Mohammed Atiquzzaman
University of Oklahoma, Computer Science, Faculty Member
Network Mobility (NEMO) has been proposed to efficiently manage the mobility of the group of hosts that are moving together as a mobile network. NEMO Basic Support Protocol (BSP) suffers from the problem of inefficient route. A number of... more
Network Mobility (NEMO) has been proposed to efficiently manage the mobility of the group of hosts that are moving together as a mobile network. NEMO Basic Support Protocol (BSP) suffers from the problem of inefficient route. A number of route optimization schemes have been proposed in the literature to solve the problem. The schemes are mainly based on four approaches – Delegationbased, Hierarchical, Source routing and BGP-assisted. The approaches have been evaluated in the literature in terms of various performance metrics. The selection of a route optimization approach for NEMO in terrestrial networks is straight forward from the evaluations that implicitly assume NEMO in such networks. However, the selection of a route optimization approach requires additional evaluations for NEMO architecture that has been proposed for satellite networks to manage the mobility of Internet Protocol-enabled devices onboard satellites. The requirement for the additional evaluations results from th...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Computer Science, Distributed Computing, Delegation, Performance Evaluation, Route Optimization, and 9 moreDynamic Software Adaptation, Prefix, Network Mobility, Analytical Model, Mobile Network, Electrical And Electronic Engineering, Limit (Mathematics), Dynamic Adaptation, and Wireless Personal Communications
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Computer Science, Distributed Computing, Telecommunications, The Internet, Satellite Communication, and 15 moreMobility Management, Computer Network, Protocols, Local Area Networks, Satellite, Network Mobility, Next Generation, Transport Layer, Low Earth Orbit, Mobility Model, Internet, Electrical And Electronic Engineering, Intelligent Networks, Satellite Network, and Next generation networking
Research Interests: Computer Science, Distributed Computing, Communication Networks, Handover, Computer Network, and 11 moreData Communication, Quality of Service, Satellite, Link Layer, Low Earth Orbit, Electrical And Electronic Engineering, Satellite Network, Channel Capacity, Literature survey, Propagation delay, and Frequency spectrum
Research Interests:
Mobile IP, a IETF standard to handle mobility of Internet hosts has some existing problems like high handover latency, packet loss, inefficient routing etc. To overcome these problems, we designed alternative novel approach called... more
Mobile IP, a IETF standard to handle mobility of Internet hosts has some existing problems like high handover latency, packet loss, inefficient routing etc. To overcome these problems, we designed alternative novel approach called Seamless IP diversity based Generalized Mobility Architecture (SIGMA), which utilizes multihoming and uses a transport layer protocol, Stream Control Transmission Protocol (SCTP). In our previous work, we have achieved a low latency handoff when MN moves between adjacent wireless network. Our ...
Abstract—In our earlier study, we proposed SIGMA, a Seamless IP diversity based Generalized Mobility Architecture. SIGMA utilizes multihoming to achieve a seamless handover of a mobile host, and is designed to solve many of the drawbacks... more
Abstract—In our earlier study, we proposed SIGMA, a Seamless IP diversity based Generalized Mobility Architecture. SIGMA utilizes multihoming to achieve a seamless handover of a mobile host, and is designed to solve many of the drawbacks of Mobile IP. In this paper, we evaluate the impact of Layer 2 connection setup on the performance of SIGMA. Various aspects of Layer 2 connection setup are considered such as Layer 2 setup latency, layer 2 beacon period, and mobile host moving speed. Criteria for performance ...
Abstract—Future Low Earth Orbiting spacecrafts will contain several IP-enabled devices that are accessible by users through ground stations. As the spacecraft moves around the Earth, mobility solution, such as Mobile IPv6 can be used to... more
Abstract—Future Low Earth Orbiting spacecrafts will contain several IP-enabled devices that are accessible by users through ground stations. As the spacecraft moves around the Earth, mobility solution, such as Mobile IPv6 can be used to handle the mobility of the devices when satellites handover between ground stations. However, if the devices are connected to an on-board Local Area Network, the mobility management of the devices can be handled in an aggregated fashion using Network Mobility from the Internet Engineering Task Force. ...
Research Interests:
Mobile IP to handle mobility of Internet hosts at the network layer. Mobile IP, however, suffers from a number of drawbacks such as high handover latency, packet loss, and conflict with network security solutions. In this paper, we... more
Mobile IP to handle mobility of Internet hosts at the network layer. Mobile IP, however, suffers from a number of drawbacks such as high handover latency, packet loss, and conflict with network security solutions. In this paper, we describe TraSH, a new Transport Layer Seamless Handover solution to mobility. TraSH utilizes multi-homing to achieve a seamless handover of a mobile host, and is designed to solve many of the drawbacks of Mobile IP. Various aspects, such as handover, signalling, location management, data transfer, and ...
Research Interests:
Abstract—The Internet Engineering Task Force has developed Mobile IP to handle mobility of Internet hosts at the network layer. Spacecrafts in space are analogous to mobile nodes in the terrestrial network. NASA has been experimenting... more
Abstract—The Internet Engineering Task Force has developed Mobile IP to handle mobility of Internet hosts at the network layer. Spacecrafts in space are analogous to mobile nodes in the terrestrial network. NASA has been experimenting with Mobile IP to handle handoffs in space networks. Mobile IP, however, suffers from a number of drawbacks such as high handoff latency, packet loss, and interoperability issues with network security solutions. In this paper, we describe TraSH-SN, a new Transport Layer Seamless Handover scheme ...
Research Interests:
Abstract—NASA has been interested in having Internet connectivity in space for quite some time. This would allow scientists with direct Internet access to data and devices on the satellites. The rotation of Low Earth Orbiting (LEO)... more
Abstract—NASA has been interested in having Internet connectivity in space for quite some time. This would allow scientists with direct Internet access to data and devices on the satellites. The rotation of Low Earth Orbiting (LEO) satellites around the Earth result in handover of satellites between ground stations. Two types of handover can be observed in space: Link layer and Network layer. Researchers at The University of Oklahoma and NASA Glenn Research Center have been developing a Seamless IP diversity-based ...
Clustering is an important concept in vehicular ad hoc network (VANET) where several vehicles join to form a group based on common features. Mobility-based clustering strategies are the most common in VANET clustering; however, machine... more
Clustering is an important concept in vehicular ad hoc network (VANET) where several vehicles join to form a group based on common features. Mobility-based clustering strategies are the most common in VANET clustering; however, machine learning and fuzzy logic algorithms are also the basis of many VANET clustering algorithms. Some VANET clustering algorithms integrate machine learning and fuzzy logic algorithms to make the cluster more stable and efficient. Network mobility (NEMO) and multi-hop-based strategies are also used for VANET clustering. Mobility and some other clustering strategies are presented in the existing literature reviews; however, extensive study of intelligence-based, mobility-based, and multi-hop-based strategies still missing in the VANET clustering reviews. In this paper, we presented a classification of intelligence-based clustering algorithms, mobility-based algorithms, and multi-hop-based algorithms with an analysis on the mobility metrics, evaluation crite...
Research Interests:
Performance evaluation of multiple-bus multiprocessor systems is usually carried out under the assumption of uniform memory reference model. Hot spots arising in multiprocessor systems due to the use of shared variable, synchronization... more
Performance evaluation of multiple-bus multiprocessor systems is usually carried out under the assumption of uniform memory reference model. Hot spots arising in multiprocessor systems due to the use of shared variable, synchronization primitives etc., give rise to non-uniform memory reference patterns. The objective of this paper is to study the performance of multiple bus multiprocessor system in the presence of
Research Interests:
Research Interests:
Hot spot in multistage interconnection networks (MSIN) results in performance degradation of the network. This paper develops an analytical model for the performance evaluation of unbu ered MSINs under a single hot spot, followed by a... more
Hot spot in multistage interconnection networks (MSIN) results in performance degradation of the network. This paper develops an analytical model for the performance evaluation of unbu ered MSINs under a single hot spot, followed by a performance comparison with bu ered MSINs. A hybrid network is proposed for optimum performance.
OIl (·() fa () 11tBuf huks. l< ac. h SE has ft finite 11urnbcr Of bIll/E1I· p· I (Iic·+ lm], T (IIO· IIZ ('sI//.[fla/vl'tca/.·%'llI'fAtot (/4· 5/· IL·‥/1j4· b//Iifl. l1 (/Lt)· 니 r·(N· E (ll·'y ('‥... more
OIl (·() fa () 11tBuf huks. l< ac. h SE has ft finite 11urnbcr Of bIll/E1I· p· I (Iic·+ lm], T (IIO· IIZ ('sI//.[fla/vl'tca/.·%'llI'fAtot (/4· 5/· IL·‥/1j4· b//Iifl. l1 (/Lt)· 니 r·(N· E (ll·'y ('‥ O'r·% rSn-po (ttatI.//zl) Il (f'Crs. u'f'0/i1. I1· 7C1c141s1r0/1i·(r/nd· Nlh. r· 1 (1I, lflfiPfo/PIuf· ll (A· fy·· yj· E3· Mr>· t·,%, t· L· h· c-·/l·> rItLy·>(+ Ij (· tye'M/lO/I/b· 8c PIra·(pI/(l·· r8-.
Research Interests:
Research Interests: Distributed Computing, Communication systems, Optical Communication, Electromagnetic Interference, Millimeter Wave Antennas, and 11 moreData Communication, Optical Communication System, Research and Development, Radio Frequency, Cost effectiveness, Optical network, Anxiety and Depression, Network Architecture, Community Networks, Local Area Network, and Electrical And Electronic Engineering
Continued progress in both civil and military avionics applications is overstressing the capabilities of existing radio-frequency (RF) communication networks based on coaxial cables on board modern aircrafts. Future avionics systems will... more
Continued progress in both civil and military avionics applications is overstressing the capabilities of existing radio-frequency (RF) communication networks based on coaxial cables on board modern aircrafts. Future avionics systems will require high-bandwidth on-board communication links that are lightweight, immune to electromagnetic interference, and highly reliable. Fiber optic communication technology can meet all these challenges in a cost-effective manner. Recently, digital fiber-optic ...
Research Interests:
A recent trend in Internet usage has seen large amounts of multimedia data due to increasingly large numbers of mobile users. To facilitate higher bandwidth, modern mobile routers are capable of supporting simultaneous multi-band,... more
A recent trend in Internet usage has seen large amounts of multimedia data due to increasingly large numbers of mobile users. To facilitate higher bandwidth, modern mobile routers are capable of supporting simultaneous multi-band, leading to
less interference, higher capacity and better reliability. However, there exists neither previous work that attempts to maximize utilization of available bandwidth in order
to increase performance of multi-band mobile routers through the sharing of traffic classes among different frequency bands of the multi-band mobile router by scheduling, nor that shows multi-band routers are better than single band routers in realistic scenarios. In this paper, we have proposed a novel scheduling algorithm for multi-band mobile routers which transmits different classes of traffic through different frequency bands to achieve improved performance. We have developed an analytical model to perform queuing analysis of the proposed scheduling algorithm for multi-band mobile routers and derived various performance metrics, validated by extensive simulations. Our results show that the proposed scheduling model can improve performance by ensuring maximum possible utilization through sharing of capacities
among the bands in multi-band systems. We show our results by comparing proposed multi-band scheduling model with single and current multi-band scheduling models. In addition, we compare single and multi-band mobile routers. It is evident from our results that multi-band systems are not always better than single band systems although multi-band systems are expected to have better performance. Based on the
results, we have listed recommendations for selecting single or multi-band systems and allocation policies according to traffic conditions, and their priorities. Our proposed scheduling algorithms and related analysis will help network engineers build next generation mobile routers with higher throughput and utilization, ensuring less packet loss of different classes of traffic.
less interference, higher capacity and better reliability. However, there exists neither previous work that attempts to maximize utilization of available bandwidth in order
to increase performance of multi-band mobile routers through the sharing of traffic classes among different frequency bands of the multi-band mobile router by scheduling, nor that shows multi-band routers are better than single band routers in realistic scenarios. In this paper, we have proposed a novel scheduling algorithm for multi-band mobile routers which transmits different classes of traffic through different frequency bands to achieve improved performance. We have developed an analytical model to perform queuing analysis of the proposed scheduling algorithm for multi-band mobile routers and derived various performance metrics, validated by extensive simulations. Our results show that the proposed scheduling model can improve performance by ensuring maximum possible utilization through sharing of capacities
among the bands in multi-band systems. We show our results by comparing proposed multi-band scheduling model with single and current multi-band scheduling models. In addition, we compare single and multi-band mobile routers. It is evident from our results that multi-band systems are not always better than single band systems although multi-band systems are expected to have better performance. Based on the
results, we have listed recommendations for selecting single or multi-band systems and allocation policies according to traffic conditions, and their priorities. Our proposed scheduling algorithms and related analysis will help network engineers build next generation mobile routers with higher throughput and utilization, ensuring less packet loss of different classes of traffic.
Research Interests:
An increasing number of internet connected devices access large multimedia files over the Internet. Therefore, the bandwidth demand is exponentially increasing. To satisfy users’ demands, multi-band wireless routers, which simultaneously... more
An increasing number of internet connected devices access large multimedia files over the Internet. Therefore, the
bandwidth demand is exponentially increasing. To satisfy users’
demands, multi-band wireless routers, which simultaneously
support several bands, are developed. However, current multi-band routers do not attempt to maximize the utilization of
frequency bands nor consider the energy consumption. There
are a limited number of previous works on multi-band wireless
routers and those works do not address the energy efficiency
and utilization problems of multi-band routers. Therefore, we
have proposed an energy aware scheduling algorithm to ensure
maximize utilization of multi-band routers while decreasing
energy consumption through band sharing. Results show that the proposed method uses system resources efficiently and decreases energy consumption of the multi-band systems up to 60%. Our proposed scheduling algorithm and related analysis will help network engineers build next generation wireless routers by considering performance metrics such as throughput and energy usage of multi-band Wi-Fi routers.
bandwidth demand is exponentially increasing. To satisfy users’
demands, multi-band wireless routers, which simultaneously
support several bands, are developed. However, current multi-band routers do not attempt to maximize the utilization of
frequency bands nor consider the energy consumption. There
are a limited number of previous works on multi-band wireless
routers and those works do not address the energy efficiency
and utilization problems of multi-band routers. Therefore, we
have proposed an energy aware scheduling algorithm to ensure
maximize utilization of multi-band routers while decreasing
energy consumption through band sharing. Results show that the proposed method uses system resources efficiently and decreases energy consumption of the multi-band systems up to 60%. Our proposed scheduling algorithm and related analysis will help network engineers build next generation wireless routers by considering performance metrics such as throughput and energy usage of multi-band Wi-Fi routers.
Research Interests:
Simplicity of usage, flexibility of data access, ease of maintenance, time and energy efficiency, and pay as you go policy have increased the usage of cloud computing over traditional computing. Cloud computing should be able to meet the... more
Simplicity of usage, flexibility of data access, ease of
maintenance, time and energy efficiency, and pay as you go policy have increased the usage of cloud computing over traditional computing. Cloud computing should be able to meet the performance expectations of different classes of customers. However, inefficient scheduling algorithms decrease the quality of service experienced by users. To improve quality of service, several scheduling algorithms have been proposed in the literature. However, these scheduling algorithms do not consider heterogeneous servers or different priority classes of customers. Our objective is to satisfy performance expectations of customers by proposing a Heterogeneous Dynamic Dedicated Server Scheduling (h-DDSS) while considering heterogeneous servers and different priority classes of customers. Results show that h-DDSS architecture can provide improved customer throughput and drop rate over homogeneous DDSS in cloud computing. Our proposed scheduling algorithm and related analysis will help cloud service providers build efficient cloud service architectures which are adaptable to homogeneous and heterogeneous environments by considering different types of priority class performances, such as, drop rate, throughput, and utilization.
maintenance, time and energy efficiency, and pay as you go policy have increased the usage of cloud computing over traditional computing. Cloud computing should be able to meet the performance expectations of different classes of customers. However, inefficient scheduling algorithms decrease the quality of service experienced by users. To improve quality of service, several scheduling algorithms have been proposed in the literature. However, these scheduling algorithms do not consider heterogeneous servers or different priority classes of customers. Our objective is to satisfy performance expectations of customers by proposing a Heterogeneous Dynamic Dedicated Server Scheduling (h-DDSS) while considering heterogeneous servers and different priority classes of customers. Results show that h-DDSS architecture can provide improved customer throughput and drop rate over homogeneous DDSS in cloud computing. Our proposed scheduling algorithm and related analysis will help cloud service providers build efficient cloud service architectures which are adaptable to homogeneous and heterogeneous environments by considering different types of priority class performances, such as, drop rate, throughput, and utilization.
Research Interests:
Large multimedia files are accessed by a high number of mobile users over the Internet. Therefore, the bandwidth demand for mobile Internet access is increasing exponentially. To answer users’ demand, carrier aggregation is proposed in... more
Large multimedia files are accessed by a high number of mobile users over the Internet. Therefore, the bandwidth demand for mobile Internet access is increasing exponentially. To answer users’ demand, carrier aggregation is proposed in LTE-A. In carrier aggregation, the best available one or more
component carriers of each band are assigned as primary
and secondary component carriers to each user for efficient
services. The previous works have significantly improved the
performance of LTE-A by using efficient component carrier
assignment methods. The previous works, however, have two
limitations. First, they have not investigated which of joint
or partial secondary component carrier assignment techniques
shows better performance. Second, overall system performance is analyzed in order to evaluate methods by ignoring system
behavior such as packet drops and delay metrics during carrier
reassignment operations. Therefore, in this paper, firstly, packet drops and delay which are experienced by users during the carrier reassignment process are investigated. Secondly, joint
and partial secondary component carrier assignment techniques are compared. Results show that the partial carrier assignment technique increases efficiency of resource usage, throughput rate up to 15% and decreases average delay time up to 12%.
component carriers of each band are assigned as primary
and secondary component carriers to each user for efficient
services. The previous works have significantly improved the
performance of LTE-A by using efficient component carrier
assignment methods. The previous works, however, have two
limitations. First, they have not investigated which of joint
or partial secondary component carrier assignment techniques
shows better performance. Second, overall system performance is analyzed in order to evaluate methods by ignoring system
behavior such as packet drops and delay metrics during carrier
reassignment operations. Therefore, in this paper, firstly, packet drops and delay which are experienced by users during the carrier reassignment process are investigated. Secondly, joint
and partial secondary component carrier assignment techniques are compared. Results show that the partial carrier assignment technique increases efficiency of resource usage, throughput rate up to 15% and decreases average delay time up to 12%.
Research Interests:
The number of mobile users is rapidly increasing. Therefore, the bandwidth demand of mobile users significantly growing. To answer users’ demand, Carrier Aggregation is proposed in LTE systems. In Carrier Aggregation, communication... more
The number of mobile users is rapidly increasing. Therefore, the bandwidth demand of mobile users significantly growing. To answer users’ demand, Carrier Aggregation is proposed in LTE systems. In Carrier Aggregation, communication between users and base stations are achieved by multi bands which have different coverage areas and mobile users can simultaneously connect one or multi carrier components in
each band. Because of mobility of users and quality of carriers,
the best available Carrier Components of each band should
be assigned to each user in order to provide desired service
to users. Several works have been proposed in the literature
to address Carrier Components assignment methods in LTE
systems by using Channel Quality Indicator, quality of service
and service types. Although the previous works on carrier
assignment methods significantly increase the performance of
LTE system, continuously increasing bandwidth demand of users forces the operators to manage resource allocation more intelligently. Therefore, we have proposed a novel Carrier Component assignment method which considers user profiles and channel quality indicator to increase quality of services and experiences getting by mobile users. Results show that the proposed method uses system resources efficiently and can improve performance of LTE systems. Our method will help service providers build efficient carrier components assignment methods through considering user profile and performance metrics, such as band usage, throughput and delay.
each band. Because of mobility of users and quality of carriers,
the best available Carrier Components of each band should
be assigned to each user in order to provide desired service
to users. Several works have been proposed in the literature
to address Carrier Components assignment methods in LTE
systems by using Channel Quality Indicator, quality of service
and service types. Although the previous works on carrier
assignment methods significantly increase the performance of
LTE system, continuously increasing bandwidth demand of users forces the operators to manage resource allocation more intelligently. Therefore, we have proposed a novel Carrier Component assignment method which considers user profiles and channel quality indicator to increase quality of services and experiences getting by mobile users. Results show that the proposed method uses system resources efficiently and can improve performance of LTE systems. Our method will help service providers build efficient carrier components assignment methods through considering user profile and performance metrics, such as band usage, throughput and delay.
Research Interests: Wireless Communications, Wireless networks, Wireless Networks (Computer Science), Long Term Evolution (LTE), WiMAX/LTE/LTE-A, and 10 moreLTE, GSM, WiMAX, LTE, Wireless technology (3G & LTE), Wireless Communications and Networking, LTE, LTE-Advanced, MIMO, LTE-Advanced and beyond, 3GPP LTE/LTE-A, 4G LTE networking, LTE A Throughput, and LTE Optimization
Internet usage over mobile devices is on the rise. The bandwidth demand for mobile Internet access is also increasing with the number of mobile users. To answer users’ demand, carrier aggregation is proposed in LTE-A system. In carrier... more
Internet usage over mobile devices is on the rise. The bandwidth demand for mobile Internet access is also increasing
with the number of mobile users. To answer users’ demand,
carrier aggregation is proposed in LTE-A system. In carrier
aggregation, the best available one or more component carriers of each band are assigned to each user to provide efficient services. Several works have been reported in the literature on mandatory and periodic component carrier assignment methods. Although the previous works, especially periodic component carrier assignment methods, have significantly improved performance of LTE and LTE-A systems, many limitations still exist. One limitation of previous works is that data transfer is interrupted during periodic component carrier assignment operation which can decrease performance of the system. Therefore, in this paper, selective periodic component carrier assignment technique which allows continues data transfer during periodic carrier assignment operations is proposed. Results show that the proposed technique
increases throughput rate up to 25% and decreases average delay time up to 35%.
with the number of mobile users. To answer users’ demand,
carrier aggregation is proposed in LTE-A system. In carrier
aggregation, the best available one or more component carriers of each band are assigned to each user to provide efficient services. Several works have been reported in the literature on mandatory and periodic component carrier assignment methods. Although the previous works, especially periodic component carrier assignment methods, have significantly improved performance of LTE and LTE-A systems, many limitations still exist. One limitation of previous works is that data transfer is interrupted during periodic component carrier assignment operation which can decrease performance of the system. Therefore, in this paper, selective periodic component carrier assignment technique which allows continues data transfer during periodic carrier assignment operations is proposed. Results show that the proposed technique
increases throughput rate up to 25% and decreases average delay time up to 35%.
Research Interests: Wireless Communications, Wireless networks, Wireless Networks (Computer Science), Long Term Evolution (LTE), WiMAX/LTE/LTE-A, and 9 moreLTE, GSM, WiMAX, LTE, Wireless technology (3G & LTE), LTE, LTE-Advanced, MIMO, LTE-Advanced and beyond, 3GPP LTE/LTE-A, 4G LTE networking, LTE A Throughput, and LTE Optimization
To facilitate higher bandwidth for multimedia traffic, modern routers support simultaneous multi-band communication, leading to less interference, higher capacity and better reliability. However, there is lack of quantitative evaluation... more
To facilitate higher bandwidth for multimedia traffic, modern routers support simultaneous multi-band communication, leading to less interference, higher capacity and better reliability. However, there is lack of quantitative evaluation to
judge whether multi-band is better than single band router
in realistic scenarios. Our objective is to propose a scheduling
algorithm for multi-band routers and compare single band and
multi-band system with different allocation policies. We have used
different scheduling algorithms for multi-band routers which
transmit different classes of traffic through different frequency
bands, thereby achieving improved performance. By comparing
multi-band and single band mobile router performances, we have found out that one of them is not always better than the other although multi-band is expected to have better performance.
judge whether multi-band is better than single band router
in realistic scenarios. Our objective is to propose a scheduling
algorithm for multi-band routers and compare single band and
multi-band system with different allocation policies. We have used
different scheduling algorithms for multi-band routers which
transmit different classes of traffic through different frequency
bands, thereby achieving improved performance. By comparing
multi-band and single band mobile router performances, we have found out that one of them is not always better than the other although multi-band is expected to have better performance.
Research Interests:
Recent trends in Internet usage have seen large amount of multimedia data due to increasingly large number of mobile users. To facilitate higher bandwidth, modern mobile routers are capable of supporting simultaneous multi-band, leading... more
Recent trends in Internet usage have seen large amount of multimedia data due to increasingly large number of mobile users. To facilitate higher bandwidth, modern mobile
routers are capable of supporting simultaneous multi-band,
leading to less interference, higher capacity. However, there exists no previous work that attempts to maximize utilization through sharing of traffic among different frequency bands. In this paper, we have proposed a novel scheduling algorithm for multi-band mobile routers which transmits different classes of traffic through
different frequency bands to achieve improved performance.
We have developed an analytical model to perform queuing
analysis of the proposed multi-band system and derived various performance metrics, validated by extensive simulations. Our results show that the proposed architecture can ensure maximum possible utilization through sharing of capacities among the bands. Our proposed scheduling algorithm and related analytical model can help network engineers build next generation mobile routers with higher throughput and utilization ensuring least packet loss for different classes of traffic.
routers are capable of supporting simultaneous multi-band,
leading to less interference, higher capacity. However, there exists no previous work that attempts to maximize utilization through sharing of traffic among different frequency bands. In this paper, we have proposed a novel scheduling algorithm for multi-band mobile routers which transmits different classes of traffic through
different frequency bands to achieve improved performance.
We have developed an analytical model to perform queuing
analysis of the proposed multi-band system and derived various performance metrics, validated by extensive simulations. Our results show that the proposed architecture can ensure maximum possible utilization through sharing of capacities among the bands. Our proposed scheduling algorithm and related analytical model can help network engineers build next generation mobile routers with higher throughput and utilization ensuring least packet loss for different classes of traffic.
Research Interests:
Increasing number of mobile users accesses large multimedia files (such as high definition audio, video, images, etc.) over the Internet. Therefore, the bandwidth demand for mobile Internet access is getting exponentially larger. To... more
Increasing number of mobile users accesses large
multimedia files (such as high definition audio, video, images, etc.) over the Internet. Therefore, the bandwidth demand for mobile Internet access is getting exponentially larger. To answer users’
demand, Carrier Aggregation is proposed in LTE-A. In Carrier
Aggregation, multi bands are used and the bands have supported different coverage. Therefore, mobile users can simultaneously connect only one or multi bands. Because of mobility of users,
traffic types and assigned channel errors, the best available
Carrier Components of each band should be assigned to each
user in order to increase quality of services. Several works have
been proposed in the literature to address Carrier Components
assignment to mobile users by using Channel Quality Indicator,
quality of service and traffic types in LTE systems. However, continuously increasing data requests of users forces the operators to manage traffic more intelligently. Therefore, we have proposed a novel Carrier Component assignment method which considers
user profiles and traffic types to increase quality of services
and experiences getting by mobile users. Results show that
the proposed method uses system resources efficiently and can
provide improved throughput rate in LTE and LTE-A systems.
Our method will help service providers build efficient Carrier
Component assignment services through considering user profile and traffic types.
multimedia files (such as high definition audio, video, images, etc.) over the Internet. Therefore, the bandwidth demand for mobile Internet access is getting exponentially larger. To answer users’
demand, Carrier Aggregation is proposed in LTE-A. In Carrier
Aggregation, multi bands are used and the bands have supported different coverage. Therefore, mobile users can simultaneously connect only one or multi bands. Because of mobility of users,
traffic types and assigned channel errors, the best available
Carrier Components of each band should be assigned to each
user in order to increase quality of services. Several works have
been proposed in the literature to address Carrier Components
assignment to mobile users by using Channel Quality Indicator,
quality of service and traffic types in LTE systems. However, continuously increasing data requests of users forces the operators to manage traffic more intelligently. Therefore, we have proposed a novel Carrier Component assignment method which considers
user profiles and traffic types to increase quality of services
and experiences getting by mobile users. Results show that
the proposed method uses system resources efficiently and can
provide improved throughput rate in LTE and LTE-A systems.
Our method will help service providers build efficient Carrier
Component assignment services through considering user profile and traffic types.
Research Interests:
Simplicity of usage, flexibility of data access, ease of maintenance, time and energy efficiency, and pay as you go policy have increased the usage of cloud computing over traditional computing. Cloud computing should be able to meet the... more
Simplicity of usage, flexibility of data access, ease of
maintenance, time and energy efficiency, and pay as you go policy have increased the usage of cloud computing over traditional computing. Cloud computing should be able to meet the performance expectations of different classes of customers. On the contrary, inefficient scheduling algorithms decrease the quality of service experienced by users. To improve quality of service, there are several proposed scheduling algorithms in the literature. However, these scheduling algorithms are limited because they do not consider different types of customers. Our objective is to satisfy performance expectations of customers by proposing an efficient Dynamic Dedicated Server Scheduling (DDSS) while considering different types of customers. Results show that the customer drop rate and throughput can be significantly improved by DDSS. Our proposed scheduling and related analysis will help cloud service providers build efficient cloud computing service architectures through considering different types of priority class performances such as, drop rate, throughput, and utilization.
maintenance, time and energy efficiency, and pay as you go policy have increased the usage of cloud computing over traditional computing. Cloud computing should be able to meet the performance expectations of different classes of customers. On the contrary, inefficient scheduling algorithms decrease the quality of service experienced by users. To improve quality of service, there are several proposed scheduling algorithms in the literature. However, these scheduling algorithms are limited because they do not consider different types of customers. Our objective is to satisfy performance expectations of customers by proposing an efficient Dynamic Dedicated Server Scheduling (DDSS) while considering different types of customers. Results show that the customer drop rate and throughput can be significantly improved by DDSS. Our proposed scheduling and related analysis will help cloud service providers build efficient cloud computing service architectures through considering different types of priority class performances such as, drop rate, throughput, and utilization.
Research Interests:
RefDoc Refdoc est un service / is powered by. ...
RefDoc Refdoc est un service / is powered by. ...
Research Interests:
This sender-based TFRC is shown to share the bottleneck-bandwidth fairly under various network conditions, allowing Saratoga to be adapted for shared links or for the congested Internet, while still supporting the asymmetric environments... more
This sender-based TFRC is shown to share the bottleneck-bandwidth fairly under various network conditions, allowing Saratoga to be adapted for shared links or for the congested Internet, while still supporting the asymmetric environments that Saratoga was originally developed for.
Abstract In this paper, we study the impact of multistreaming on the performance of SCTP over satellite networks. We first show that multistreaming results in higher goodput than single streams when the receiver buffer is constrained as... more
Abstract In this paper, we study the impact of multistreaming on the performance of SCTP over satellite networks. We first show that multistreaming results in higher goodput than single streams when the receiver buffer is constrained as in the case of wireless handheld devices. We then demonstrate that the multistreaming feature of SCTP results in reduced buffer requirements at the receiver in the presence of losses in the satellite network.
Real-time measurement and analysis of road traffic flow parameters such as volume, speed and queue are increasingly required for traffic control and management. Image processing is considered as an attractive and flexible technique for... more
Real-time measurement and analysis of road traffic flow parameters such as volume, speed and queue are increasingly required for traffic control and management. Image processing is considered as an attractive and flexible technique for automatic analysis of road traffic scenes for the measurement and data collection of road traffic parameters. In this paper, the authors describe a novel image processing based approach for analysis of road traffic scenes.
ABSTRACT Free space optics (FSO) is a technology that uses modulated optical beams to transmit information line-of-sight through the atmosphere. To date, the primary focus of FSO research and development has been toward the transmission... more
ABSTRACT Free space optics (FSO) is a technology that uses modulated optical beams to transmit information line-of-sight through the atmosphere. To date, the primary focus of FSO research and development has been toward the transmission of digital signals, primarily for “last mile” applications. This paper reports the use of FSO to transport modulated radio frequency (RF) analog signals, together with an investigation of key performance measures. Results indicate minimal RF signal distortion when transmitted over FSO.
Abstract To provide ubiquitous terrestrial Internet coverage mobility and Internet-based access to data generated by satellites, there is a strong desire to integrate the terrestrial Internet and satellite networks. This requires... more
Abstract To provide ubiquitous terrestrial Internet coverage mobility and Internet-based access to data generated by satellites, there is a strong desire to integrate the terrestrial Internet and satellite networks. This requires satellites that are based on IP for communications. Rotation of low Earth orbit satellites around the Earth results in communicating with different ground stations over time, and requires mobility management protocols for seamless communication between the Internet and satellite networks.
Abstract The delay-constrained capacitated minimum spanning tree (DC-CMST) problem of finding several broadcast trees from a source node is discussed. While the traditional CMST problem deals with only the traffic capacity constraint... more
Abstract The delay-constrained capacitated minimum spanning tree (DC-CMST) problem of finding several broadcast trees from a source node is discussed. While the traditional CMST problem deals with only the traffic capacity constraint served by a port of the source node, and delay-constrained minimum spanning tree (DCMST) considers only the maximum end-end delay constraint, the DC-CMST problem deals with both the mean network delay and traffic capacity constraints.
The Hough transform is a projection-based transform which can be used to detect shapes in images. One of the disadvantages of the transform is its requirement for large amounts of computing power. Parallel machines have given programmers... more
The Hough transform is a projection-based transform which can be used to detect shapes in images. One of the disadvantages of the transform is its requirement for large amounts of computing power. Parallel machines have given programmers the potential for incredible computing power. To obtain maximum performance from parallel machines, parallel algorithms should be designed to reflect the architecture of the parallel machine.
Abstract With the convergence of wireless communication and IP-based networking technologies, future IP-based wireless networks are expected to support real-time multimedia. IP services over wireless networks (eg wireless access to... more
Abstract With the convergence of wireless communication and IP-based networking technologies, future IP-based wireless networks are expected to support real-time multimedia. IP services over wireless networks (eg wireless access to Internet) enhance the mobility and flexibility of traditional IP network users.
Performance analysis of multiple-bus systems is usually carried out under the assumption of a uniform memory request model. Hot spots arising in multiprocessor systems give rise to non-uniform memory requests. It is known that a hot spot... more
Performance analysis of multiple-bus systems is usually carried out under the assumption of a uniform memory request model. Hot spots arising in multiprocessor systems give rise to non-uniform memory requests. It is known that a hot spot memory request pattern results in a significant degradation in the performance of a buffered multistage interconnection network.
ABSTRACT The Stream Control Transmission Protocol (SCTP) has been developed as a reliable transport layer protocol for carrying PSTN signalling messages over IP networks. However, its advanced congestion control and fault tolerant... more
ABSTRACT The Stream Control Transmission Protocol (SCTP) has been developed as a reliable transport layer protocol for carrying PSTN signalling messages over IP networks. However, its advanced congestion control and fault tolerant features make it a strong competitor to the widely used TCP protocol. In this paper, we investigate the performance of SCTP in an error-prone network, and compared it with that of TCP.
Seamless IP diversity based Generalized Mobility Architecture. SIGMA utilizes IP diversity to achieve a seamless handover of a mobile host, and is designed to solve many of the drawbacks of Mobile IP. In this paper, we evaluate the impact... more
Seamless IP diversity based Generalized Mobility Architecture. SIGMA utilizes IP diversity to achieve a seamless handover of a mobile host, and is designed to solve many of the drawbacks of Mobile IP. In this paper, we evaluate the impact of Layer 2 connection setup on the performance of SIGMA. Various aspects of Layer 2 connection setup, such as Layer 2 setup latency, Layer 2 beacon period, and mobile host moving speed, are considered. Criteria for performance evaluation include handover latency, packet loss, throughput.
abstract Aeronautical Telecommunication Network (ATN) has been developed by the International Civil Aviation Organization to integrate Air-Ground and Ground-Ground data communication for aeronautical applications into a single network... more
abstract Aeronautical Telecommunication Network (ATN) has been developed by the International Civil Aviation Organization to integrate Air-Ground and Ground-Ground data communication for aeronautical applications into a single network serving Air Traffic Control and Aeronautical Operational Communications. To carry time critical information required for aeronautical applications, ATN provides different Quality of Services (QoS) to applications.
Abstract—Future Low Earth Orbiting spacecrafts will contain several IP-enabled devices that are accessible by users through ground stations. As the spacecraft moves around the Earth, mobility solution, such as Mobile IPv6 can be used to... more
Abstract—Future Low Earth Orbiting spacecrafts will contain several IP-enabled devices that are accessible by users through ground stations. As the spacecraft moves around the Earth, mobility solution, such as Mobile IPv6 can be used to handle the mobility of the devices when satellites handover between ground stations.
Abstract—Increasing demand for mobility in wireless data network has given rise to various mobility management schemes. Most of the analysis on mobility protocols used Random Waypoint (RWP) mobility model which fails to represent... more
Abstract—Increasing demand for mobility in wireless data network has given rise to various mobility management schemes. Most of the analysis on mobility protocols used Random Waypoint (RWP) mobility model which fails to represent realistic movement pattern. In this paper, we have used City Section Mobility (CSM) model, a realistic mobility model, to compare the signaling costs of two host-mobility protocols: HIMPv6 and SIGMA, and two network-mobility protocols: NEMO BSP and SINEMO.
Abstract In this paper, options for providing seamless service delivery to mobile terminals via heterogeneous radio access networks are considered. Despite its current popularity, the Mobile IP solution for mobility management of mobile... more
Abstract In this paper, options for providing seamless service delivery to mobile terminals via heterogeneous radio access networks are considered. Despite its current popularity, the Mobile IP solution for mobility management of mobile hosts is discounted due to problems associated with introducing the required network infrastructure and poor handover performance. Rather, the solution described here comprises of a number of key technologies working together.
Abstract: Most current web application use small objects to increase the data transfer speed between server and client. This leads to completion of the object transfer while the TCP is still in the initial slow-start phase, which starts... more
Abstract: Most current web application use small objects to increase the data transfer speed between server and client. This leads to completion of the object transfer while the TCP is still in the initial slow-start phase, which starts with an initial window size. SCTP, a new transport layer protocol, uses congestion control mechanism that is similar to that of TCP but complements TCP's deficiencies in web applications.
Abstract Improving the quality of service (QoS) of Internet traffic is widely recognized as a critical issue for nextgeneration networks. To address this issue, we are using OPNET to help us to conceive, develop, and test new schemes,... more
Abstract Improving the quality of service (QoS) of Internet traffic is widely recognized as a critical issue for nextgeneration networks. To address this issue, we are using OPNET to help us to conceive, develop, and test new schemes, models, and algorithms for improving the performance of active queue management. Different proposed schemes, models, and algorithms are implemented in OPNET, and are evaluated by simulations.
Abstract—This paper deals with the problem of finding the topology of local access tree networks. The problem consists of finding the best way to link end-user nodes to a center node. In graph-theoretical terms, it consists of determining... more
Abstract—This paper deals with the problem of finding the topology of local access tree networks. The problem consists of finding the best way to link end-user nodes to a center node. In graph-theoretical terms, it consists of determining a set of CMST (Capacitated Minimal Spanning Tree) and solving an NP-complete combinatorial problem.
Abstract. In this chapter, we discuss the transport layer design issues in a mobile wireless networks. The focus will be put on two transport protocols: Transmission Control Protocol (TCP) and Stream Control Transmission Protocol (SCTP).... more
Abstract. In this chapter, we discuss the transport layer design issues in a mobile wireless networks. The focus will be put on two transport protocols: Transmission Control Protocol (TCP) and Stream Control Transmission Protocol (SCTP). TCP is the dominant transport protocol currently used for most Internet services such as Web browsing, file transfer, remote login etc.
Mobility support is one of the important features in mobile communication network Mobility management enables telecommunication network to locate roaming mobile terminals (MT) for call delivery and maintain connections with MTs that... more
Mobility support is one of the important features in mobile communication network Mobility management enables telecommunication network to locate roaming mobile terminals (MT) for call delivery and maintain connections with MTs that change their point of attachment. Location management is one of the most important issues in mobility management. Its protocols deal with querying and storing information in location database and sending paging signals to locate the user within the network.
Abstract To support IP-mobility of networks in motion, IETF proposed Network Mobility (NEMO) protocol that uses various signaling messages to ensure connectivity of the mobile nodes with the Internet and to maintain security of ongoing... more
Abstract To support IP-mobility of networks in motion, IETF proposed Network Mobility (NEMO) protocol that uses various signaling messages to ensure connectivity of the mobile nodes with the Internet and to maintain security of ongoing sessions by protecting the binding updates. As the next-generation wireless and mobile network is supposed to be a unified network based
Abstract Switching elements in interconnection networks for highly parallel shared memory computer systems may be implemented with different internal buffer structures. A multistage interconnection network (MIN) consist of several stages... more
Abstract Switching elements in interconnection networks for highly parallel shared memory computer systems may be implemented with different internal buffer structures. A multistage interconnection network (MIN) consist of several stages of small crossbar switching elements (SEs). The aim of this paper is to study the performance of a multibuffered MIN with different SEs architecture, in the presence of uniform and nonuniform traffic.
Abstract Multimedia is characterized by bursty traffic and often stringent real-time constraints. Multimedia traffic requires quality of service guarantees. This gives rise to traffic management issues in order to obtain high network... more
Abstract Multimedia is characterized by bursty traffic and often stringent real-time constraints. Multimedia traffic requires quality of service guarantees. This gives rise to traffic management issues in order to obtain high network utilization and quality of service guarantee to the multimedia stream. The aim of this article is to present an overview of the traffic management issues and their possible solutions for transmission of multimedia over asynchronous transfer mode networks
Abstract Domain name system (DNS) can be deployed in the network as a location manager (LM) for mobility management. The suitability of domain name system (DNS) as an LM can be measured by how successfully it can serve to locate a mobile... more
Abstract Domain name system (DNS) can be deployed in the network as a location manager (LM) for mobility management. The suitability of domain name system (DNS) as an LM can be measured by how successfully it can serve to locate a mobile host.
The current Internet does not provide Quality of Service (QoS) to real-time applications such as audio and video. Differentiated Service (DiffServ) network (1] is currently being developed by IETF to add QoS to the current Internet... more
The current Internet does not provide Quality of Service (QoS) to real-time applications such as audio and video. Differentiated Service (DiffServ) network (1] is currently being developed by IETF to add QoS to the current Internet without fundamental change to the current Internet protocol. Diffserv distinguishes between edge and core networks/routers.
Page 1. 1 Mohammed Atiquzzaman, University of Dayton, Email: atiq@ieee.org QoS for Real Time Applications over Next Generation Data Networks Project Status Report: Part 1 June 2, 2000... more
Page 1. 1 Mohammed Atiquzzaman, University of Dayton, Email: atiq@ieee.org QoS for Real Time Applications over Next Generation Data Networks Project Status Report: Part 1 June 2, 2000 http://www.engr.udayton.edu/faculty/matiquzz/Pres/QoS.pdf University of Dayton Mohammed Atiquzzaman Jyotsna Chitri Faruque Ahamed Hongjun Su Haowei Bai Ohio State University Raj Jain Mukul Goyal Bharani Chadavala Arindam Paul Chun Lei Liu Wei Sun Arian Durresi NASA Glenn Will Ivancic Page 2.
Abstract Network Mobility (NEMO) efficiently manages the mobility of multiple nodes that moves together as a mobile network. A major limitation of the basic protocol in NEMO is the inefficient route between end hosts. A number of prefix... more
Abstract Network Mobility (NEMO) efficiently manages the mobility of multiple nodes that moves together as a mobile network. A major limitation of the basic protocol in NEMO is the inefficient route between end hosts. A number of prefix delegation-based schemes have been proposed in the literature to solve the route optimization problem in NEMO. Approaches used by the schemes trade off delivery of packets through the partially optimized route with signaling and other processing overheads.
A tiquzzaman t is a great pleasure and an honor for us to take on the responsibility of editors for the Internet Technology Series of IEEE Communications Magazine. The previous series editors, Khaled Elsayed and Michah Lerner, have done a... more
A tiquzzaman t is a great pleasure and an honor for us to take on the responsibility of editors for the Internet Technology Series of IEEE Communications Magazine. The previous series editors, Khaled Elsayed and Michah Lerner, have done a marvelous job in carrying out the responsibility. We hope to build on their success, and continue their efforts in improving the
Abstract—IP mobility can be handled at different layers of the protocol stack. Mobile IP has been developed to handle mobility of Internet hosts at the network layer. As an alternative solution, a number of transport layer mobility... more
Abstract—IP mobility can be handled at different layers of the protocol stack. Mobile IP has been developed to handle mobility of Internet hosts at the network layer. As an alternative solution, a number of transport layer mobility protocols have been proposed, for example, MSOCKS and TCP connection migration solution in the context of TCP, and M-SCTP and mobile SCTP in the context of SCTP.
ABSTRACT TCP is the dominant transport layer protocol in the IP protocol suite. Due to a number of limitations of TCP, the Internet Engineering Task Force has developed a new transport layer protocol, called Stream Control Transmission... more
ABSTRACT TCP is the dominant transport layer protocol in the IP protocol suite. Due to a number of limitations of TCP, the Internet Engineering Task Force has developed a new transport layer protocol, called Stream Control Transmission Protocol (SCTP). It was initially developed as a reliable transport layer protocol for carrying PSTN signalling messages over IP networks. However, its advanced congestion control and fault tolerant features make it a strong competitor to the widely used TCP protocol.
Abstract A mobile ad hoc network (MANET) is a network that allows mobile servers and clients to communicate in the absence of a fixed infrastructure. MANET is a fast growing area of research as it finds use in a variety of applications.... more
Abstract A mobile ad hoc network (MANET) is a network that allows mobile servers and clients to communicate in the absence of a fixed infrastructure. MANET is a fast growing area of research as it finds use in a variety of applications. In order to facilitate efficient data access and update, databases are deployed on MANETs. These databases that operate on MANETs are referred to as MANET databases.
Abstract. In this chapter, we discuss transport layer design issues in mobile wireless networks. The focus is on two transport protocols: Transmission Control Protocol (TCP) and Stream Control Transmission Protocol (SCTP). TCP is the... more
Abstract. In this chapter, we discuss transport layer design issues in mobile wireless networks. The focus is on two transport protocols: Transmission Control Protocol (TCP) and Stream Control Transmission Protocol (SCTP). TCP is the dominant transport protocol which is currently used for most Internet services such as Web browsing, file transfer, remote login etc. SCTP is a recently developed protocol by IETF for signaling message transport over IP networks, and it is being actively studied to explore its applicability to new arenas.
Abstract We present a new multi-rate architecture for decoding irregular LDPC codes in IEEE 802.16 e WiMax standard. The proposed architecture utilizes the value-reuse property of offset min-sum, block-serial scheduling of computations... more
Abstract We present a new multi-rate architecture for decoding irregular LDPC codes in IEEE 802.16 e WiMax standard. The proposed architecture utilizes the value-reuse property of offset min-sum, block-serial scheduling of computations and turbo decoding message passing algorithm. The decoder has the following advantages: 55% savings in memory, reduction of routers by 50%, and increase of throughput by 2times when compared to the recent state-of-the-art decoder architectures.
Abstract Domain name system (DNS) maps domain names to IP addresses in the Internet. DNS can, however, be used as a location manager (LM) for mobility management in wireless mobile networks. The suitability and performance of DNS as a LM... more
Abstract Domain name system (DNS) maps domain names to IP addresses in the Internet. DNS can, however, be used as a location manager (LM) for mobility management in wireless mobile networks. The suitability and performance of DNS as a LM for locating mobile hosts (MH) has not been studied in the past. In this paper, we develop an analytical model to measure the performance of DNS as LM for IP diversity based mobility management.
Abstract: Multistage interconnection networks are used to connect processors to memories in shared memory multiprocessor systems. The performance evaluation of such networks is usually based on the assumption of a uniform memory reference... more
Abstract: Multistage interconnection networks are used to connect processors to memories in shared memory multiprocessor systems. The performance evaluation of such networks is usually based on the assumption of a uniform memory reference pattern. Hot spots in such networks give rise to a nonuniform memory reference pattern and result in a degradation in performance. A comparison of the performance of unbuffered and buffered networks under a nonuniform traffic pattern is given.
Detection of patterns in images is an important high-level task in automated manufacturing using machine vision. Straight lines, circles and ellipses are considered to be the basic building blocks of a large number of patterns occurring... more
Detection of patterns in images is an important high-level task in automated manufacturing using machine vision. Straight lines, circles and ellipses are considered to be the basic building blocks of a large number of patterns occurring in real-world images. Real-world images frequently contain noise and occlusions resulting in discontinuous patterns in noisy images. The Hough transform can be used to detect parametric patterns, such as straight lines and circles, embedded in noisy images.
Abstract In our earlier study, we proposed SIGMA, a seamless IP diversity based generalized mobility architecture. SIGMA utilizes IP diversity to achieve a seamless handover of a mobile host, and is designed to solve many of the drawbacks... more
Abstract In our earlier study, we proposed SIGMA, a seamless IP diversity based generalized mobility architecture. SIGMA utilizes IP diversity to achieve a seamless handover of a mobile host, and is designed to solve many of the drawbacks of mobile IP. In this paper, we compare the handover latency of SIGMA and recent MIPv6 enhancements, namely, FMIPv6, HMIPv6, and FHMIPv6.
Abstract—The Hough transform is highly compute bound and demands a large amount of storage. In this correspondence, a novel multiresolution implementation of the Hough transform has been proposed. To reduce the computing time, it exploits... more
Abstract—The Hough transform is highly compute bound and demands a large amount of storage. In this correspondence, a novel multiresolution implementation of the Hough transform has been proposed. To reduce the computing time, it exploits the reduced information content of multiresolution images and accumulator arrays and uses a simple peak detection algorithm. Logarithmic parameter-range reduction ensures faster convergence than other methods. The algorithm takes care of discretization errors.
Abstract Wireless sensor networks is an emerging paradigm of computing and networking where a node may be selfpowered, and have sensing, computing, and communication capabilities. They have been proposed for use in a wide variety of... more
Abstract Wireless sensor networks is an emerging paradigm of computing and networking where a node may be selfpowered, and have sensing, computing, and communication capabilities. They have been proposed for use in a wide variety of applications. The objective of this article is to describe a wireless sensor network for monitoring of the health of aircraft engines. We describe the architecture of the wireless sensor network along with how it fits into the general area of wireless sensor networks.
Abstract IETF has proposed mobile IPv6-based network mobility (NEMO) basic support protocol (BSP) to support network mobility. NEMO BSP inherits all the drawbacks of mobile IPv6, such as inefficient routing path, single point of failure,... more
Abstract IETF has proposed mobile IPv6-based network mobility (NEMO) basic support protocol (BSP) to support network mobility. NEMO BSP inherits all the drawbacks of mobile IPv6, such as inefficient routing path, single point of failure, high handover latency and packet loss, and high packet overhead. To address these drawbacks, we proposed an IP diversity-based network mobility management scheme called seamless IP-diversity based network mobility (SINEMO).
Abstract The stream control transmission protocol has recently been standardized as a new transport layer protocol in the IP protocol suite. SCFP is based on the TCP protocol, but incorporates a number of advanced and unique features that... more
Abstract The stream control transmission protocol has recently been standardized as a new transport layer protocol in the IP protocol suite. SCFP is based on the TCP protocol, but incorporates a number of advanced and unique features that are not available in TCP. Although the suitability of TCP over satellite networks has been widely studied, the suitability of SCTP over satellite networks remains to be evaluated. The objective of this article is to investigate the suitability of SCTP for data communications over satellite networks.
Abstract The Internet Engineering Task Force (IETF) has defined the Guaranteed Service (GS) with firm delay and bandwidth guarantees in the Integrated Services model for supporting real-time services. Before setting up a GS flow, the... more
Abstract The Internet Engineering Task Force (IETF) has defined the Guaranteed Service (GS) with firm delay and bandwidth guarantees in the Integrated Services model for supporting real-time services. Before setting up a GS flow, the traffic parameter of the source have to be specified in terms of a number of token bucket traffic descriptors. The source must conform to these descriptors by shaping its traffic. In this paper we study a novel traffic shaper for efficient transmission of MPEG video streams over GS.
Abstract Explicit congestion notification (ECN), when used with random early detection (RED) gateways, reduces packet losses and delays of transport control protocol (TCP) based applications. However, choosing the buffer size and optimum... more
Abstract Explicit congestion notification (ECN), when used with random early detection (RED) gateways, reduces packet losses and delays of transport control protocol (TCP) based applications. However, choosing the buffer size and optimum parameter values of RED buffers are still open research issues. In this paper, we first present a model to determine the optimal value of RED's maximum threshold to achieve zero packet loss at RED gateways.
Abstract Among the schemes, proposed in the literature to solve the route optimization problem in NEtwork Mobility (NEMO), the prefix delegation-based schemes perform better than other schemes. Depending on the way the prefix are... more
Abstract Among the schemes, proposed in the literature to solve the route optimization problem in NEtwork Mobility (NEMO), the prefix delegation-based schemes perform better than other schemes. Depending on the way the prefix are delegated, the prefix delegation-based schemes result in difference in performance under different speed at various distance from the home network (network to which mobile network usually belongs).
Asynchronous transfer mode (ATM) switches based on shared buffering are known to have better performance and buffer utilization than input or output queued switches. Shared buffer switches do not suffer from head of line blocking which is... more
Asynchronous transfer mode (ATM) switches based on shared buffering are known to have better performance and buffer utilization than input or output queued switches. Shared buffer switches do not suffer from head of line blocking which is a problem in simple input buffering. Shared buffer switches have previously been studied under uniform and unbalanced traffic patterns. However, due to the complexity of the model, the performance of such a switch, in the presence of a single hot spot, has not been fully explored.
Abstract Mobile IP has been developed by IETF to handle mobility of Internet hosts at the network layer. Mobile IP suffers from a number of drawbacks, including low survivability due to single-point failure of Home Agents. Recently,... more
Abstract Mobile IP has been developed by IETF to handle mobility of Internet hosts at the network layer. Mobile IP suffers from a number of drawbacks, including low survivability due to single-point failure of Home Agents. Recently, Seamless IP diversity based Generalized Mobility Architecture (SIGMA) was proposed to support low latency, low packet loss mobility of IP hosts. In this paper, we show that the location management scheme used in SIGMA enhances the survivability of the SIGMA-based mobile network.
Abstract Current Web applications use HTTP (hyper text transfer protocol) over TCP (transmission control protocol) to retrieve objects over the Internet. SCTP (stream control transmission protocol) is a recently proposed transport... more
Abstract Current Web applications use HTTP (hyper text transfer protocol) over TCP (transmission control protocol) to retrieve objects over the Internet. SCTP (stream control transmission protocol) is a recently proposed transport protocol with very similar congestion control mechanisms as TCP, except the initial congestion window during the slow start phase.
Abstract—NASA has been interested in having Internet connectivity in space for quite some time. This would allow scientists with direct Internet access to data and devices on the satellites. The rotation of Low Earth Orbiting (LEO)... more
Abstract—NASA has been interested in having Internet connectivity in space for quite some time. This would allow scientists with direct Internet access to data and devices on the satellites. The rotation of Low Earth Orbiting (LEO) satellites around the Earth result in handover of satellites between ground stations. Two types of handover can be observed in space: Link layer and Network layer.
Abstract Active buffer management can improve the performance of Transmission Control Protocol/Internet Protocol-based networks. Random early detection (RED), an active queue management scheme, has been proposed by the Internet... more
Abstract Active buffer management can improve the performance of Transmission Control Protocol/Internet Protocol-based networks. Random early detection (RED), an active queue management scheme, has been proposed by the Internet Engineering Task Force for next-generation Internet routers. RED uses a number of parameters, such as buffer thresholds, a packet drop probability and a weight parameter. RED suffers from low throughput and large delay/jitter and induces instability in networks.
Abstract Mobile Ad hoc networks (MANETs) are composed of a collection of independent nodes usually connected by low bandwidth Radio Frequency (RF) links which are challenging for transmitting video and high bandwidth applications for... more
Abstract Mobile Ad hoc networks (MANETs) are composed of a collection of independent nodes usually connected by low bandwidth Radio Frequency (RF) links which are challenging for transmitting video and high bandwidth applications for rescue workers in emergency situations.
Abstract Ad hoc networks are characterized by nodes which are usually connected by low data rate Radio Frequency (RF) links when compared to optical links. RF links make it challenging for transmitting video and running high bandwidth... more
Abstract Ad hoc networks are characterized by nodes which are usually connected by low data rate Radio Frequency (RF) links when compared to optical links. RF links make it challenging for transmitting video and running high bandwidth applications over ad hoc networks. The objective of this paper is to develop a novel routing protocol for Ad hoc networks consisting of hybrid nodes using high bandwidth Free Space Optical (FSO) and RF links, with FSO being the primary link and RF as backup in case of FSO link failures.
Abstract Since the need for high alignment accuracy of the transmitter and receiver to construct a viable connection is a primary challenge for mobile free-space optical (FSO) links, developing an efficient transmitter control system for... more
Abstract Since the need for high alignment accuracy of the transmitter and receiver to construct a viable connection is a primary challenge for mobile free-space optical (FSO) links, developing an efficient transmitter control system for acquisition and tracking is an urgent demand. This paper investigates a novel control algorithm within different transmitter designs in FSO mobile networks. The fiber bundles are utilized so that the beam deflection properties of a lens can be exploited to affect beam steering.
Abstract IETF has proposed mobile IPv6-based network mobility (NEMO) basic support protocol (BSP) to support network mobility. NEMO BSP inherits all the drawbacks of mobile IPv6, such as inefficient routing path, single point of failure,... more
Abstract IETF has proposed mobile IPv6-based network mobility (NEMO) basic support protocol (BSP) to support network mobility. NEMO BSP inherits all the drawbacks of mobile IPv6, such as inefficient routing path, single point of failure, high handover latency and high packet overhead. To address these drawbacks, a new network mobility scheme, called seamless IP-diversity based network mobility (SINEMO), has been proposed.
Abstract A number of prefix delegation-based schemes have been proposed in the literature to solve the route optimization problem in NEMO, where a group of hosts move together as a mobile network. The route optimization solutions generate... more
Abstract A number of prefix delegation-based schemes have been proposed in the literature to solve the route optimization problem in NEMO, where a group of hosts move together as a mobile network. The route optimization solutions generate different amounts of overheads that depend on the characteristics of the mobile network and mobility parameters.
Abstract Wireless networks are becoming more heterogeneous; different classes of networks coexist and users want to connect to any available network, anytime. So, it is important to have a mobility management scheme that can manage... more
Abstract Wireless networks are becoming more heterogeneous; different classes of networks coexist and users want to connect to any available network, anytime. So, it is important to have a mobility management scheme that can manage handoff for both interclass and intraclass mobility so that the users can connect to and roam between any network.
Abstract Seamless IP-diversity based NEtwork MObility (SINEMO) was proposed to address a number of drawbacks of the Network Mobility (NEMO) protocol for mobility management of a number of hosts moving together in a Local Area Network.... more
Abstract Seamless IP-diversity based NEtwork MObility (SINEMO) was proposed to address a number of drawbacks of the Network Mobility (NEMO) protocol for mobility management of a number of hosts moving together in a Local Area Network. Increasing number of mobile hosts results in higher level of signalling cost on the mobility agents in a mobility protocol.
Abstract Stream control transmission protocol (SCTP) is a new transport layer protocol which is being standardized by IETF. Multi-homing, one of the most attractive features of SCTP, makes it competitive in high-availability and mobile... more
Abstract Stream control transmission protocol (SCTP) is a new transport layer protocol which is being standardized by IETF. Multi-homing, one of the most attractive features of SCTP, makes it competitive in high-availability and mobile environments. In this paper, we propose an analytical model for evaluating the performance of SCTP multi-homing. The proposed model has been validated against and found to agree well with simulation results.
Abstract Among the route optimization schemes in NEtwork MObility (NEMO), the prefix delegation-based schemes perform better than other schemes. Since the prefix delegation-based schemes are designed for communication between a mobile... more
Abstract Among the route optimization schemes in NEtwork MObility (NEMO), the prefix delegation-based schemes perform better than other schemes. Since the prefix delegation-based schemes are designed for communication between a mobile network and a wired network, they lack evaluation for the case of intra mobile network communication involving MIPv6 incapable hosts in a mobile network.
∎ TCP is the main transport protocol in the Internet protocol suite∎ Original TCP performed poorly in satellite networks• errors• long propagation delay.∎ Many schemes for enhancing TCP for satellite networks.∎ IETF developing Stream... more
∎ TCP is the main transport protocol in the Internet protocol suite∎ Original TCP performed poorly in satellite networks• errors• long propagation delay.∎ Many schemes for enhancing TCP for satellite networks.∎ IETF developing Stream Control Transmission Protocol (SCTP) for PSTN signaling over IP.
Abstract. The stream control transmission protocol (SCTP) is a new transport protocol, which provides multi-streaming and multi-homing features. Especially, recent SCTP extensions with dynamic address reconfiguration supports transport... more
Abstract. The stream control transmission protocol (SCTP) is a new transport protocol, which provides multi-streaming and multi-homing features. Especially, recent SCTP extensions with dynamic address reconfiguration supports transport layer mobility. We address web agent framework supporting seamless transport layer mobility in the wired and wireless environment. Our proposed framework for mobile web agent deploys SCTP with dynamic address reconfiguration.
Abstract This study deals with the delay-constrained minimum cost loop problem (DC-MCLP) of finding several loops from a source node. The DC-MCLP consists of finding a set of minimum cost loops to link end-nodes to a source node... more
Abstract This study deals with the delay-constrained minimum cost loop problem (DC-MCLP) of finding several loops from a source node. The DC-MCLP consists of finding a set of minimum cost loops to link end-nodes to a source node satisfying the traffic requirements at end-nodes and the required mean delay of the network. In the DC-MCLP, the objective function is to minimize the total link cost. This paper proposes a dynamic programming based three phase algorithm that solves the DC-MCLP.
Abstract Mobility management in an IP network requires a location manager to identify the location of mobile host. Four mobility management schemes (SIGMA, Migrate, HIP and TCP-R) in the literature have proposed Domain Name Service as a... more
Abstract Mobility management in an IP network requires a location manager to identify the location of mobile host. Four mobility management schemes (SIGMA, Migrate, HIP and TCP-R) in the literature have proposed Domain Name Service as a location manager, with performance results available only for SIGMA. In this paper, we introduce a generic analytical model to compare the performance of DNS as location manager for all the four schemes.
Abstract—Network survivability, which reflects the ability of a network to continue to function during and after natural or man-made disturbances, is a crucial aspect for any kind communication. It goes beyond security and fault tolerance... more
Abstract—Network survivability, which reflects the ability of a network to continue to function during and after natural or man-made disturbances, is a crucial aspect for any kind communication. It goes beyond security and fault tolerance to focus on delivery of essential services and rapid recovery of full services when situation improves. Wireless and space networks have the challenge of survivability, since users and network entities are mobile and the communication channels are accessible to anyone.
Abstract The Stream Control Transmission Protocol (SCTP) is an IETF-standard transport layer protocol in the IP protocol suite. SCTP is very attractive for data communication over satellite networks due to its unique features such as... more
Abstract The Stream Control Transmission Protocol (SCTP) is an IETF-standard transport layer protocol in the IP protocol suite. SCTP is very attractive for data communication over satellite networks due to its unique features such as multihoming and multistreaming that are not present in TCP. SIGMA, an SCTP-based mobility management scheme, has been developed for space networks. RTEMS, an open source Real Time Operating System (RTOS), is used by the computers onboard several spacecraft.
Abstract Continued progress in both civil and military radio-frequency (RF) digital avionics applications is overstressing the capabilities and reliability of existing RF communication networks based on coaxial cables on board modern... more
Abstract Continued progress in both civil and military radio-frequency (RF) digital avionics applications is overstressing the capabilities and reliability of existing RF communication networks based on coaxial cables on board modern aircrafts. Future avionics systems will require high-bandwidth on-board communication links that are lightweight, immune to electromagnetic interference, and highly reliable. Fibre-optic networks can meet all these challenges in a cost-effective manner.
Abstract Internet mobility protocols are designed to support handover between different wireless networks. Many of them, such as Mobile IPv6, suffer problems such as high handover latency, high packet overhead, high packet loss during... more
Abstract Internet mobility protocols are designed to support handover between different wireless networks. Many of them, such as Mobile IPv6, suffer problems such as high handover latency, high packet overhead, high packet loss during handoff, requirement for infrastructure change, etc. To solve these problems, SEamless MObility using SHIM6 (SEMO6), a multihoming based mobility protocol framework for host mobility, has been proposed.
Page 1. 1 Applicability and Performance of NEMO in Satellite Networks Abu Zafar M. Shahriar1 Mohammad Atiquzzaman1 William Ivancic2 1School of Computer Science University of Oklahoma. 2NASA Glenn Research Center June 24, 2008 Page 2.
Yong-Jin Lee M. Atiquzzaman Dept. of Computer Science School of Computer Science Woosong University University of Oklahoma Taejon, 300-718, Korea Norman, OK 73019, USA yjlee@ woosong. ac. kr atiq@ ou. edu Keywords: mean waiting time, mean... more
Yong-Jin Lee M. Atiquzzaman Dept. of Computer Science School of Computer Science Woosong University University of Oklahoma Taejon, 300-718, Korea Norman, OK 73019, USA yjlee@ woosong. ac. kr atiq@ ou. edu Keywords: mean waiting time, mean around time, web transaction, HTTP, TCP, T-TCP
Abstract An important characteristic of a mobile ad hoc network routing protocol is connectivity maintenance. The protocol's ability to maintain routes and react to topology changes due to link failures affects the delay, packet loss, and... more
Abstract An important characteristic of a mobile ad hoc network routing protocol is connectivity maintenance. The protocol's ability to maintain routes and react to topology changes due to link failures affects the delay, packet loss, and throughput of real-time applications. However, the time required to recover from a link failure in the current AODV protocol is too long for real-time applications.
Internet customers want to improve their capacities of interaction with humans and machines, by means of new advanced (but simple to use) applications and tools. They would like Internet to be not only a large container of information,... more
Internet customers want to improve their capacities of interaction with humans and machines, by means of new advanced (but simple to use) applications and tools. They would like Internet to be not only a large container of information, but also an environment where people can move, look, meet, talk, listen, learn, work, sell and buy.
Abstract Image processing involves processing a vast amount of data, and hence requires a large amount of computing power. Multiprocessor systems have been suggested as sources of large amount of computing power. For e cient execution of... more
Abstract Image processing involves processing a vast amount of data, and hence requires a large amount of computing power. Multiprocessor systems have been suggested as sources of large amount of computing power. For e cient execution of an algorithm in a multiprocessor system, the structure of the algorithm should mirror the architecture of the multiprocessor system. A linear array multiprocessor architecture for low level image processing is described in this paper.
Abstract—Network mobility (NEMO) protocols are required to maintain connectivity of ongoing sessions for mobile networks that can be formed in bus, train, aircrafts with a wide variety of on-board IP-enabled devices. However, basic NEMO... more
Abstract—Network mobility (NEMO) protocols are required to maintain connectivity of ongoing sessions for mobile networks that can be formed in bus, train, aircrafts with a wide variety of on-board IP-enabled devices. However, basic NEMO suffers from large delay and packet loss and fails to ensure seamless handover. Multi-homed network mobility solutions can facilitate seamless handover of mobile networks by making use of multiple network interfaces of NEMO.
Abstract This paper suggests a systolic array implementation of fuzzy expert systems based on a fuzzy evidential reasoning methodology. Evidential reasoning systems are compute-bound in general, and fuzzy systems match a larger number of... more
Abstract This paper suggests a systolic array implementation of fuzzy expert systems based on a fuzzy evidential reasoning methodology. Evidential reasoning systems are compute-bound in general, and fuzzy systems match a larger number of rules than simple symbolic reasoning systems. The fuzzy evidential system proposed, which is a combination of both, needs much more computation than either of these two independently. To speed up processing in such a system the suggested implementation is useful
Abstract Random early detection (RED) is expected to eliminate global synchronization by random active packet drop. Its packet drop probability is decided by the maximum packet drop probability in its drop function, the buffer thresholds,... more
Abstract Random early detection (RED) is expected to eliminate global synchronization by random active packet drop. Its packet drop probability is decided by the maximum packet drop probability in its drop function, the buffer thresholds, and the average queue length. It has been observed that, for a large number of connections, a small value of maximum drop probability does not eliminate global synchronization.
Abstract The throughput degradation of Transport Control Protocol (TCP)/Internet Protocol (IP) networks over lossy links due to the coexistence of congestion losses and link corruption losses is very similar to the degradation of... more
Abstract The throughput degradation of Transport Control Protocol (TCP)/Internet Protocol (IP) networks over lossy links due to the coexistence of congestion losses and link corruption losses is very similar to the degradation of processor performance (ie, cycle per instruction) due to control hazards in computer design. First, two types of loss events in networks with lossy links are analogous to two possibilities of a branching result in computers (taken vs. not taken).
Abstract-In parallel with the growth of VoIP services, a large number of manufacturers have begun to develop multimode devices capable of connecting to multiple wireless access networks simultaneously. These multimode terminals have, in... more
Abstract-In parallel with the growth of VoIP services, a large number of manufacturers have begun to develop multimode devices capable of connecting to multiple wireless access networks simultaneously. These multimode terminals have, in principle, the capability to support seamless handover between different radio access networks. One handover solution that utilises the IP diversity which these multimode devices can deliver is SIGMA. SIGMA is a promising end-to-end transport layer handover solution based on SCTP.
Abstract Performance modeling of multiple-bus systems is usually carried out under the assumption of uniform memory reference model. Hot spots arising in multiprocessor systems give rise to non-uniform memory references. It is known that... more
Abstract Performance modeling of multiple-bus systems is usually carried out under the assumption of uniform memory reference model. Hot spots arising in multiprocessor systems give rise to non-uniform memory references. It is known that a hot spot memory reference pattern results in a significant degradation in the performance of a buffered multistage interconnection network. The aim of this research is to study the effect of hot spots on the performance of buffered multiple-bus systems.
ABSTRACT The Hough Transform is a powerful tool for the recognition of patterns in images. However, its high computational cost both in terms of time and storage requirements restricts its usefulness on single processor machines.... more
ABSTRACT The Hough Transform is a powerful tool for the recognition of patterns in images. However, its high computational cost both in terms of time and storage requirements restricts its usefulness on single processor machines. Multiprocessor implementations of the algorithm are therefore attractive. We have investigated algorithms for use on the Fujitsu AP1000 distributed memory multiprocessor, and implemented them using amostly'functional language called paraML.
Abstract—To facilitate seamless Internet connectivity to mobile nodes, we earlier proposed SIGMA, a transport layer mobility management protocol. However, frequent handoff of the mobile nodes produce excessive signaling overhead in the... more
Abstract—To facilitate seamless Internet connectivity to mobile nodes, we earlier proposed SIGMA, a transport layer mobility management protocol. However, frequent handoff of the mobile nodes produce excessive signaling overhead in the bandwidthlimited air interfaces and cause large handover delay, thereby degrading the performance. Hierarchical mobility management for SIGMA aims at resolving this problem by introducing micromobility agents in the hierarchy.
ABSTRACT In this paper, we analyze the end-to-end statistical delay performance of Motion Pictures Experts Group (MPEG) compressed video flows in the next generation Internet when the flows are served by earliest deadline first (EDF)... more
ABSTRACT In this paper, we analyze the end-to-end statistical delay performance of Motion Pictures Experts Group (MPEG) compressed video flows in the next generation Internet when the flows are served by earliest deadline first (EDF) scheduling discipline at each switch. We develop a model for an isolated scheduler fed by shaped MPEG sources, and extend the model for end-to-end statisticar delay analysis for multiple hops.
A schematic design is presented for a stand-alone test device to measure all aspects of echo at the subscriber location of dial lines in telephone networks. The proposed architecture is based on off-the-shelf components such as a general... more
A schematic design is presented for a stand-alone test device to measure all aspects of echo at the subscriber location of dial lines in telephone networks. The proposed architecture is based on off-the-shelf components such as a general purpose PC and one of the available digital signal processing (DSP) boards with minimum additional hardware. Echo aspects are identified for measurements and the firmware (both hardware and software) of the design are presented.
ABSTRACT The Internet was initially designed for non real-time data communications, and hence does not provide any Quality of Service (QoS) guarantees. Differentiated Services (DiffServ) is being developed by IETF to provide QoS... more
ABSTRACT The Internet was initially designed for non real-time data communications, and hence does not provide any Quality of Service (QoS) guarantees. Differentiated Services (DiffServ) is being developed by IETF to provide QoS guarantees by carrying priority information in the packet headers. ATM is expected to coexist with DiffServ in the core of the next generation Internet.
Ab.stract Atiquzzaman, M., Performance modeling of multiprocessor systems for different data loading schemes, Microprocessing and Microprogramming 36 (1993) 167-178. When evaluating the performance of an algorithm in a multiprocessor... more
Ab.stract Atiquzzaman, M., Performance modeling of multiprocessor systems for different data loading schemes, Microprocessing and Microprogramming 36 (1993) 167-178. When evaluating the performance of an algorithm in a multiprocessor system, most authors assume that the data are already loaded in the system. This assumption gives rise to a large error between the predicted and actual performances, specially for fine-grained tasks like image processing.
Abstract Mobile IP, a IETF standard to handle mobility of Internet hosts has some existing problems like high handover latency, packet loss, inefficient routing etc. To overcome these problems, we designed alternative novel approach... more
Abstract Mobile IP, a IETF standard to handle mobility of Internet hosts has some existing problems like high handover latency, packet loss, inefficient routing etc. To overcome these problems, we designed alternative novel approach called Seamless IP diversity based Generalized Mobility Architecture (SIGMA), which utilizes multihoming and uses a transport layer protocol, Stream Control Transmission Protocol (SCTP). In our previous work, we have achieved a low latency handoff when MN moves between adjacent wireless network.
Abu S Reaz, Pulak K Chowdhury, Mohammed Atiquzzaman Telecommunications and Networks Research Lab, School of Computer Science University of Oklahoma, Norman, OK 73019-6151, USA Email:{sayeem reaz, pulak, atiq}@ ou. edu Keywords: Network... more
Abu S Reaz, Pulak K Chowdhury, Mohammed Atiquzzaman Telecommunications and Networks Research Lab, School of Computer Science University of Oklahoma, Norman, OK 73019-6151, USA Email:{sayeem reaz, pulak, atiq}@ ou. edu Keywords: Network Mobility, Mobility Management, IP Diversity, DNS, Location Management Abstract—IETF has proposed Mobile IPv6-based Network Mobility (NEMO) basic support protocol (BSP) to support network mobility.
Abstract—Mobility management of Internet nodes has been widely investigated over the last few years. Various schemes have been developed to support mobility in the Internet. While designing mobility management schemes, a few fundamental... more
Abstract—Mobility management of Internet nodes has been widely investigated over the last few years. Various schemes have been developed to support mobility in the Internet. While designing mobility management schemes, a few fundamental considerations have to be followed to achieve better performance. In this paper, we present a number of important issues that have to be considered while designing mobility management schemes.
We hope that these three articles provide some understanding of challenges toward the mobile Internet of the future and its emerging applications. It is only a start to long-term research and development for mobile applications and... more
We hope that these three articles provide some understanding of challenges toward the mobile Internet of the future and its emerging applications. It is only a start to long-term research and development for mobile applications and services. We would like to thank Editor-in-Chief Tom Chen for his continuous support for this Feature Topic and the publication staff at ComSoc. We would like to thank all authors who submitted their articles for consideration in this issue.
Abstract We have developed an exact model and algorithm for the delay-constrained minimum cost loop problem (DC-MCLP) of finding broadcast loops from a source node. While the traditional minimum cost loop problem (MCLP) deals with only... more
Abstract We have developed an exact model and algorithm for the delay-constrained minimum cost loop problem (DC-MCLP) of finding broadcast loops from a source node. While the traditional minimum cost loop problem (MCLP) deals with only the traffic capacity constraint served by a port of source node, the DC-MCLP deals with the mean network delay and traffic capacity constraints simultaneously.
Abstract—A new end-to-end seamless mobility management protocol, called Seamless IP diversity-based Generalized Mobility Architecture (SIGMA), which utilizes multi-homing to achieve seamless handover of a mobile host and overcomes a... more
Abstract—A new end-to-end seamless mobility management protocol, called Seamless IP diversity-based Generalized Mobility Architecture (SIGMA), which utilizes multi-homing to achieve seamless handover of a mobile host and overcomes a number of performance bottlenecks and security limitations of Mobile IP, has been proposed in the literature. Various performance aspects of SIGMA have been widely studied in the literature using simulation and experimental prototype.
Abstract In network layer based mobility protocols, such as mobile IP, the correspondent node is not aware of handovers and therefore continues to send data at the same rate as before the handover which may exhibit network unfriendliness,... more
Abstract In network layer based mobility protocols, such as mobile IP, the correspondent node is not aware of handovers and therefore continues to send data at the same rate as before the handover which may exhibit network unfriendliness, especially when the capacities of the two subnets differ significantly. On the contrary, transport layer based mobility protocols, such as SIGMA, do not show such phenomena.
Abstract Hybrid Free Space Optics (FSO)/Radio Frequency (RF) communication systems have emerged as a way to improve network performance by providing enhanced availability and reliability. In an effort to mitigate individual drawbacks in... more
Abstract Hybrid Free Space Optics (FSO)/Radio Frequency (RF) communication systems have emerged as a way to improve network performance by providing enhanced availability and reliability. In an effort to mitigate individual drawbacks in the optical link during adverse weather conditions, network traffic flows simultaneously between channels. Based on the Shannon-Hartley theorem, channel capacity is dependent, among others, on both the signal to noise ratio (SNR) and channel bandwidth.
Abstract—Satellites are being used to capture real-time images, video for various purposes, such as, observing the Earth, weather data, live images for tornado, cyclones, tsunami, etc. In future, these data can be accessed by terrestrial... more
Abstract—Satellites are being used to capture real-time images, video for various purposes, such as, observing the Earth, weather data, live images for tornado, cyclones, tsunami, etc. In future, these data can be accessed by terrestrial users through the Internet. Mobility protocols aim at providing uninterrupted realtime data communication facilities through seamless Internet connectivity to hosts or networks in motion, such as in bus, train, aircraft, and satellites.
Wood et al.[1] describe Saratoga, a UDP-based protocol that sends data at a rate independent of feedback rate, and performs loss recovery based on periodic feedback. Saratoga is used to download data from Internet-enabled Disaster... more
Wood et al.[1] describe Saratoga, a UDP-based protocol that sends data at a rate independent of feedback rate, and performs loss recovery based on periodic feedback. Saratoga is used to download data from Internet-enabled Disaster Monitoring Constellation (DMC) satellites constructed by Surrey Satellite Technology. The six DMC satellites currently operational in low Earth orbit provide remote sensing images to support disaster relief. At present Saratoga is being used in a controlled environment.
Abstract A number of prefix delegation-based schemes have been proposed to solve the route optimization problem in NEMO, where a group of hosts move together as a mobile network. The schemes trade off between inefficiency of routes and... more
Abstract A number of prefix delegation-based schemes have been proposed to solve the route optimization problem in NEMO, where a group of hosts move together as a mobile network. The schemes trade off between inefficiency of routes and various overheads. With the rapid growth of mobile computing, this overhead will give rise to the scalability issue of these schemes. However, there has been no quantitative study on the asymptotic scalability analysis of these schemes.
Increasing demand for mobility in wireless data networks has given rise to various mobility management protocols. The protocols use signalling messages to maintain reachability of mobile nodes. Increase in the number of mobile nodes gives... more
Increasing demand for mobility in wireless data networks has given rise to various mobility management protocols. The protocols use signalling messages to maintain reachability of mobile nodes. Increase in the number of mobile nodes gives rise to the scalability issues that need to be dealt with to avoid performance degradation of the network.
Abstract Mobile networks can be formed in bus, train, aircrafts, satellites with a wide variety of on-board IP-enable devices and Network Mobility (NEMO) protocols are required to support uninterrupted services to ongoing sessions. Node... more
Abstract Mobile networks can be formed in bus, train, aircrafts, satellites with a wide variety of on-board IP-enable devices and Network Mobility (NEMO) protocols are required to support uninterrupted services to ongoing sessions. Node mobility has a direct impact on the performance evaluation of various NEMO protocols. However, most of the analysis on mobility protocols used random waypoint mobility model which does not always represent real-world movement patterns in city streets.
Abstract—Mobile networks can be formed in bus, train, aircrafts, satellites with a wide variety of on-board IP-enabled devices and Network Mobility (NEMO) protocols are required to support uninterrupted services to ongoing sessions.... more
Abstract—Mobile networks can be formed in bus, train, aircrafts, satellites with a wide variety of on-board IP-enabled devices and Network Mobility (NEMO) protocols are required to support uninterrupted services to ongoing sessions. Earlier works have not demonstrated seamless handover for NEMO architecture. In this work, we proposed a handover scheme for NEMO that exploits the multi-homing feature of the Mobile Router and uses make-before-break strategy to ensure seamless handover for NEMO.
Abstract To support IP-mobility of networks in motion, IETF proposed Network Mobility (NEMO) protocol that uses various signaling messages to ensure connectivity of the mobile nodes with the Internet and to maintain security of ongoing... more
Abstract To support IP-mobility of networks in motion, IETF proposed Network Mobility (NEMO) protocol that uses various signaling messages to ensure connectivity of the mobile nodes with the Internet and to maintain security of ongoing sessions by protecting the binding updates.
Abstract This index covers all technical items-papers, correspondence, reviews, etc.-that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other... more
Abstract This index covers all technical items-papers, correspondence, reviews, etc.-that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author's name.
Abstract Mobile networks (NEMO) can be formed with IP-enabled devices in motion. Mobile Router (MR) acts as the gateway for all the nodes inside a mobile network. As the MR is the key entity in NEMO, the load on MR can be very high and... more
Abstract Mobile networks (NEMO) can be formed with IP-enabled devices in motion. Mobile Router (MR) acts as the gateway for all the nodes inside a mobile network. As the MR is the key entity in NEMO, the load on MR can be very high and can become the performance bottleneck. Increase in number of MRs can improve the reliability, as a single MR can be single point of failure. There have no survivability analysis of NEMO based on multiple MRs.
Abstract Previous studies have analyzed cost and performance of multihomed network mobility management protocols, such as, Seamless IP diversity-based Network Mobility management scheme (SINEMO). However, increase in the number of mobile... more
Abstract Previous studies have analyzed cost and performance of multihomed network mobility management protocols, such as, Seamless IP diversity-based Network Mobility management scheme (SINEMO). However, increase in the number of mobile nodes raises scalability issues which can result in its performance degradation. In this paper, we have developed analytical models for scalability analysis of SINEMO in terms of network size, mobility rate, and traffic rate.
Abstract Increasing demand for mobility in wireless data network has given rise to various mobility management schemes. Most of the analysis on mobility protocols used Random Waypoint mobility model However, the analysis done earlier... more
Abstract Increasing demand for mobility in wireless data network has given rise to various mobility management schemes. Most of the analysis on mobility protocols used Random Waypoint mobility model However, the analysis done earlier ignored some major costs, resulting in an incomplete estimation and used random waypoint model which fails to represent realistic movement pattern.
Abstract—To facilitate higher bandwidth for multimedia traf-fic, modern mobile routers support simultaneous multi-band communication, leading to less interference, higher capacity and better reliability. However, there exists no... more
Abstract—To facilitate higher bandwidth for multimedia traf-fic, modern mobile routers support simultaneous multi-band communication, leading to less interference, higher capacity and better reliability. However, there exists no quantitative evaluation to judge whether multi-band is better than single band router in realistic scenario. Our main objective in this paper is to find performance of different class of traffic under single and multi-band system with respect to utilization.
16. ABSTRACT Roadway Weather Information System and Automatic Vehicle Location Coordination involves the development of an Inclement Weather Console that provides a new capability for the state of Oklahoma to monitor weather-related... more
16. ABSTRACT Roadway Weather Information System and Automatic Vehicle Location Coordination involves the development of an Inclement Weather Console that provides a new capability for the state of Oklahoma to monitor weather-related roadway conditions. The goal of this development is that motorist safety might be improved and the damage to highways and bridges caused by the application of deicing agents minimized through the use of the IWC and Decision Support Systems built upon it.
Abstract Mobility protocols are originally proposed to support ongoing Internet connectivity of hosts or networks in motion. However, the requirement of seamless connectivity in mobile environment and use of route optimization between the... more
Abstract Mobility protocols are originally proposed to support ongoing Internet connectivity of hosts or networks in motion. However, the requirement of seamless connectivity in mobile environment and use of route optimization between the communicating nodes have introduced several security vulnerabilities to mobility protocols. In this paper, we explain with illustrative examples major security threats on various components of the network involving the mobility protocol.
Abstract Multiprocessor systems are employed to perform computation-intensive tasks, like image processing in real-time. Interprocessor communications has always been a performance bottleneck in bus-oriented multiprocessor systems. A... more
Abstract Multiprocessor systems are employed to perform computation-intensive tasks, like image processing in real-time. Interprocessor communications has always been a performance bottleneck in bus-oriented multiprocessor systems. A two-dimensional array (mesh) of simple processors, operating in the SIMD mode has been found very suitable for low-level image processing. Degradation in the throughput of mesh-type multiprocessor systems due to interprocessor communications is determined.
Enterprise Networking is the interconnection of corporate, departmental, local, and remote computing and communications resources to create an enterprise-wide information utility. An enterprise could be organization, such as a business,... more
Enterprise Networking is the interconnection of corporate, departmental, local, and remote computing and communications resources to create an enterprise-wide information utility. An enterprise could be organization, such as a business, government, administration, institution, etc., having business or other operating needs. The TCP/IP protocol is the internetworking protocol which glues together millions of computer and heterogeneous networks into one global Internet.
Abstract The traffic characteristics in recent years have changed considerably having more video and audio traffic with critical real-time constraints. This situation is compounded by the increased number of mobile nodes communicating... more
Abstract The traffic characteristics in recent years have changed considerably having more video and audio traffic with critical real-time constraints. This situation is compounded by the increased number of mobile nodes communicating over Internet. Due to such high data traffic, the access routers are often overloaded with packets with different priority. The access routers have to act quickly enough to avoid loss of connection of mobile nodes' ongoing communication.
Abstract. Typical transmission control protocol (TCP) based web agents in mobile wireless environment have several deficiencies, such as performance degradation, head-of-line blocking, and unsupported mobility. The Stream Control... more
Abstract. Typical transmission control protocol (TCP) based web agents in mobile wireless environment have several deficiencies, such as performance degradation, head-of-line blocking, and unsupported mobility. The Stream Control Transmission Protocol (SCTP) is a new transport protocol, which provides multi-streaming and multi-homing features. SCTP extensions for dynamic address reconfiguration will support transport layer mobility.
Abstract. We have presented an optimal algorithm for minimal cost loop problem (MCLP), which consists of finding a set of minimum cost loops rooted at a source node. In the MCLP, the objective function is to minimize the total link cost.... more
Abstract. We have presented an optimal algorithm for minimal cost loop problem (MCLP), which consists of finding a set of minimum cost loops rooted at a source node. In the MCLP, the objective function is to minimize the total link cost. The proposed algorithm is composed of two phases: in the first phase, it generates feasible paths to satisfy the traffic capacity constraint, and finds the exact solution through matching in the second phase. In addition, we have derived several properties of the proposed algorithm.
Abstract The throughput degradation of Transport Control Protocol (TCP)/Internet Protocol (IP) networks over lossy links due to the coexistence of congestion losses and link corruption losses is very similar to the degradation of... more
Abstract The throughput degradation of Transport Control Protocol (TCP)/Internet Protocol (IP) networks over lossy links due to the coexistence of congestion losses and link corruption losses is very similar to the degradation of processor performance (ie, cycle per instruction) due to control hazards in computer design. First, two types of loss events in networks with lossy links are analogous to two possibilities of a branching result in computers (taken vs. not taken).
ABSTRACT Wireless optical nodes with mobility capabilities (mobile free space optics [FSO]) have emerged as a way to overcome limitations inherent in FSO links, for example, transmitter–receiver restrictive alignment requirement.
Interactive Video on Demand with Instantaneous Access (IVoD-i) can offer users with VCR like functions by sending requests to video servers. Earlier work has shown that the Available Bit Rate Service of ATM networks can be effectively... more
Interactive Video on Demand with Instantaneous Access (IVoD-i) can offer users with VCR like functions by sending requests to video servers. Earlier work has shown that the Available Bit Rate Service of ATM networks can be effectively used for interactive video on demand. However, non optimal values of the connection setup parameters can affect the Quality of Service (QoS) at the user. This is because the ABR service only provides minimum bandwidth guarantee for a connection.
abstract The role of the Advanced Air Transportation Technologies program undertaken at the NASA Glenn Research Centers has been focused mainly on the improvement of air transportation safety, with particular emphasis on air... more
abstract The role of the Advanced Air Transportation Technologies program undertaken at the NASA Glenn Research Centers has been focused mainly on the improvement of air transportation safety, with particular emphasis on air transportation communication systems in on-board aircraft. The conventional solutions for digital optical communications systems specifically designed for local/metro area networks are, unfortunately, not capable of transporting the microwave and millimeter RF signals used in avionics systems.
Abstract—A constellation of spacecrafts, carrying sensing equipment for collection of scientific data, can be connected using communication links to form a space sensor web. Data collected by the sensors are downloaded to Earth through... more
Abstract—A constellation of spacecrafts, carrying sensing equipment for collection of scientific data, can be connected using communication links to form a space sensor web. Data collected by the sensors are downloaded to Earth through ground stations through the sensor web. The relative motion of the spacecrafts require a mobility management scheme to maintain continuous connectivity between the sensors and computers on Earth.
Abstract Suggests a systolic array implementation of fuzzy expert systems based on possibilistic evidential reasoning methodology. Evidential reasoning systems are computationally-bounded in general, and fuzzy systems match a larger... more
Abstract Suggests a systolic array implementation of fuzzy expert systems based on possibilistic evidential reasoning methodology. Evidential reasoning systems are computationally-bounded in general, and fuzzy systems match a larger number of rules than in a simple symbolic reasoning system. The proposed possibilistic evidential system, which is a combination of both types of system, needs much more computation time than either of these two independently.
Abstract Future avionics systems will require high-bandwidth on-board communication links that are lightweight, immune to electromagnetic interference, and highly reliable. Fiber optic communication technology can meet all these... more
Abstract Future avionics systems will require high-bandwidth on-board communication links that are lightweight, immune to electromagnetic interference, and highly reliable. Fiber optic communication technology can meet all these challenges in a cost-effective manner. Recent advances in fiber optic technology, especially wavelength division multiplexing (WDM), have opened a number of possibilities for designing on-board fiber optic networks for radar and avionics RF signal distribution.
Abstract Typical intelligent transportation systems (ITS) are comprised of geographically distributed ITS devices including sensors, cameras and dynamic message signs (DMS). There are several options for providing data communication... more
Abstract Typical intelligent transportation systems (ITS) are comprised of geographically distributed ITS devices including sensors, cameras and dynamic message signs (DMS). There are several options for providing data communication between these field devices and traffic management centers (TMC). Wireless networks are attractive due to their relatively lower cost and ease of deployment compared to fixed networks.
Abstract—In this paper, we propose and evaluate a novel transport layer mobility management scheme: Seamless IP diversity based Generalized Mobility Architecture (SIGMA). SIGMA provides seamless handover for mobile hosts and is based on... more
Abstract—In this paper, we propose and evaluate a novel transport layer mobility management scheme: Seamless IP diversity based Generalized Mobility Architecture (SIGMA). SIGMA provides seamless handover for mobile hosts and is based on SCTP, which is a new reliable transport protocol introduced by IETF to transport SS7 signaling messages over IP network.
Abstract—In our earlier study, we proposed SIGMA, a Seamless IP diversity based Generalized Mobility Architecture. SIGMA utilizes multihoming to achieve a seamless handover of a mobile host, and is designed to solve many of the drawbacks... more
Abstract—In our earlier study, we proposed SIGMA, a Seamless IP diversity based Generalized Mobility Architecture. SIGMA utilizes multihoming to achieve a seamless handover of a mobile host, and is designed to solve many of the drawbacks of Mobile IP. In this paper, we evaluate the impact of Layer 2 connection setup on the performance of SIGMA. Various aspects of Layer 2 connection setup are considered such as Layer 2 setup latency, layer 2 beacon period, and mobile host moving speed.
Abstract The Internet was initially designed for non real-time data communications and hence does not provide any quality of service (QoS). The next generation Internet will be characterized by high speed and QoS guarantees. The aim of... more
Abstract The Internet was initially designed for non real-time data communications and hence does not provide any quality of service (QoS). The next generation Internet will be characterized by high speed and QoS guarantees. The aim of this paper is to develop a prioritized early packet discard (PEPD) scheme for ATM switches to provide service differentiation and QoS guarantee to end applications running over the next generation Internet.
abstract In hybrid FSO/RF (Free Space Optics/Radio Frequency) systems, the FSO link is the primary link while the RF link is the secondary (backup) link. In current hybrid systems, once the FSO signal to noise ratio (SNR) decreases above... more
abstract In hybrid FSO/RF (Free Space Optics/Radio Frequency) systems, the FSO link is the primary link while the RF link is the secondary (backup) link. In current hybrid systems, once the FSO signal to noise ratio (SNR) decreases above a preset threshold, the system switches from FSO to RF to maintain the communication connection. But this scenario does not provide maximum utilization of the available bandwidth in terms of spectrum efficiency.
ABSTRACT ATM switches based on shared bu ering are known to have better performance and bu er utilization than input or output queued switches. Although shared bu er switches do not su er from head of line blocking which is a common... more
ABSTRACT ATM switches based on shared bu ering are known to have better performance and bu er utilization than input or output queued switches. Although shared bu er switches do not su er from head of line blocking which is a common problem in simple input bu ering, their performance is adversly a ected in the case of unbalanced tra c at the inputs of the switch. In this paper, we investigate the performance of a shared bu er ATM switch in the presence of a hot spot tra c pattern.
Abstract In this study, the authors address a mobile Web agent framework based on stream control transmission protocol (SCTP) to overcome the deficiencies, which the typical mobile Web agent framework based on transmission control... more
Abstract In this study, the authors address a mobile Web agent framework based on stream control transmission protocol (SCTP) to overcome the deficiencies, which the typical mobile Web agent framework based on transmission control protocol (TCP) suffers from, such as performance degradation, head-of-line blocking and unsupported mobility in mobile wireless environment. The proposed SCTP-based mobile Web agent framework supports seamless transport layer mobility in a ubiquitous environment.
Abstract—In our earlier study, we proposed SIGMA, a Transport Layer Seamless Handover solution to mobility. SIGMA utilizes multihoming to achieve a seamless handover of a mobile host, and is designed to solve many of the drawbacks of... more
Abstract—In our earlier study, we proposed SIGMA, a Transport Layer Seamless Handover solution to mobility. SIGMA utilizes multihoming to achieve a seamless handover of a mobile host, and is designed to solve many of the drawbacks of Mobile IP. In this paper, we evaluate the signaling cost of SIGMA by using an analytical model. The signaling cost of SIGMA is also compared with Hierarchical Mobile IPv6 (HMIPv6) by using the proposed model.
Abstract Most current web application use HTTP (Hyper Text Transfer Protocol) and TCP (Transmission Control Protocol) to retrieve objects from the Internet. SCTP (Stream Control Transmission Protocol) is recently proposed transport... more
Abstract Most current web application use HTTP (Hyper Text Transfer Protocol) and TCP (Transmission Control Protocol) to retrieve objects from the Internet. SCTP (Stream Control Transmission Protocol) is recently proposed transport protocol with congestion control mechanism similar to that of TCP. Waiting delay is an important performance criterion for when transferring web object over the Internet.
Abstract Multistage switches have been used as ATM switching fabrics in broadband ISDN networks, and also to connect processors to memories in massively parallel multiprocessor systems. Previous performance models for multistage switches... more
Abstract Multistage switches have been used as ATM switching fabrics in broadband ISDN networks, and also to connect processors to memories in massively parallel multiprocessor systems. Previous performance models for multistage switches have been neither accurate enough nor based on realistic assumptions regarding modelling the correlation of the blocked packets in successive stages of the switch. Two new analytical models for accurate analysis of multistage switches are proposed.
Abstract Third generation (3G) communication networks based on low Earth orbit (LEO) satellites provide a new trend in future mobile communications. LEO satellites provide lower end-to-end delays and efficient frequency spectrum... more
Abstract Third generation (3G) communication networks based on low Earth orbit (LEO) satellites provide a new trend in future mobile communications. LEO satellites provide lower end-to-end delays and efficient frequency spectrum utilization, making it suitable for personal communication services (PCS). However, ongoing communications using LEO satellite systems experience frequent handover due to high rotational speed of satellites.
Abstract IETF proposed Hierarchical Mobile IPv6 (HMIPv6) to support host mobility and mobility management involves signaling costs at various mobility entities of the network. Widespread use of IP-enabled mobile devices have resulted in... more
Abstract IETF proposed Hierarchical Mobile IPv6 (HMIPv6) to support host mobility and mobility management involves signaling costs at various mobility entities of the network. Widespread use of IP-enabled mobile devices have resulted in increase in number of mobile users and the signaling cost on underlying mobility entities have increased significantly, which will result in their performance degradation.
Abstract Network Mobility (NEMO) has been proposed to efficiently manage the mobility of the group of hosts that are moving together as a mobile network. NEMO Basic Support Protocol (BSP) suffers from the problem of inefficient route. A... more
Abstract Network Mobility (NEMO) has been proposed to efficiently manage the mobility of the group of hosts that are moving together as a mobile network. NEMO Basic Support Protocol (BSP) suffers from the problem of inefficient route. A number of route optimization schemes have been proposed in the literature to solve the problem. The schemes are mainly based on four approaches–Delegationbased, Hierarchical, Source routing and BGP-assisted.
Aeronautical Telecommunication Network (ATN) has been developed by International Civil Aviation Organization (ICAO) to integrate air-ground and ground-ground data communications for aeronautical applications into a single network serving... more
Aeronautical Telecommunication Network (ATN) has been developed by International Civil Aviation Organization (ICAO) to integrate air-ground and ground-ground data communications for aeronautical applications into a single network serving air traffic control and aeronautical operational communications. The current ICAO ATN model specifies a standalone network with its own protocols, which requires building an expensive separate network for air-ground and ground-ground communications.
Abstract Multistage Interconnection Networks (MIN) are used to connect processors and memories in large scale scalable multiprocessor systems. MINs have also been proposed as switching fabrics in ATM networks in the future Broadband ISDN... more
Abstract Multistage Interconnection Networks (MIN) are used to connect processors and memories in large scale scalable multiprocessor systems. MINs have also been proposed as switching fabrics in ATM networks in the future Broadband ISDN networks. A MIN consists of several stages of small crossbar switching elements (SE). Buffers ore used in the SEs to increase the throughput of the MIN and prevent internal loss of packets. Different buffering schemes for the SEs are discussed in this paper.
Abstract Paging is a well established technique to reduce signalling cost in mobile devices. Different proposals in literature have shown the implementation and improvement of Mobile IP with paging. Here we propose P-SIGMA, an improved... more
Abstract Paging is a well established technique to reduce signalling cost in mobile devices. Different proposals in literature have shown the implementation and improvement of Mobile IP with paging. Here we propose P-SIGMA, an improved and signalling cost-effective version of SIGMA, an IP diversity based end-to-end mobility scheme.
Abstract To support IP-mobility of networks in motion, IETF proposed Network Mobility (NEMO) protocol that uses various signaling messages to ensure connectivity of the mobile nodes with the Internet. However, there has been no... more
Abstract To support IP-mobility of networks in motion, IETF proposed Network Mobility (NEMO) protocol that uses various signaling messages to ensure connectivity of the mobile nodes with the Internet. However, there has been no comprehensive cost analysis of mobility protocol entities that considers all possible costs. In this paper, we have developed analytical models to estimate total costs of key mobility management entities of NEMO.
Abstract During flight, aircraft avionics transmit and receive RF signals to/from antennas over coaxial cables. As the density and complexity of onboard avionics increases, the electromagnetic interference (EMI) environment degrades... more
Abstract During flight, aircraft avionics transmit and receive RF signals to/from antennas over coaxial cables. As the density and complexity of onboard avionics increases, the electromagnetic interference (EMI) environment degrades proportionately, leading to decreasing signal-to-noise ratios (SNRs) and potential safety concerns. The coaxial cables are inherently lossy, limiting the RF signal bandwidth while adding considerable weight.
Abstract IETF has developed Mobile IP to support mobility of IP hosts at the network layer. The national aeronautics and space administration has implemented mobile IP to handle handovers in space networks. Due to a number of limitations... more
Abstract IETF has developed Mobile IP to support mobility of IP hosts at the network layer. The national aeronautics and space administration has implemented mobile IP to handle handovers in space networks. Due to a number of limitations of Mobile IP, such as high handover latency, packet loss rate, and conflict with existing network security solutions, a new IP-diversity based mobility management scheme, called SIGMA, has been developed through collaborative efforts of NASA and University of Oklahoma.
Abstract The authors have developed an exact model to evaluate the performance of multistage interconnection networks using internal shared buffering. The model assumes a general output distribution which allows the study of the... more
Abstract The authors have developed an exact model to evaluate the performance of multistage interconnection networks using internal shared buffering. The model assumes a general output distribution which allows the study of the performance of such networks under any desired output distribution. Among many possible output distributions, uniform, hot-spot and favourite distributions are studied.
Abstract Network mobility (NEMO) protocols can be used to manage aggregate mobility of multiple IP-enabled devices on-board a Low Earth Orbit satellite (a mobile network on-board). NEMO protocols enjoy several performance advantages, such... more
Abstract Network mobility (NEMO) protocols can be used to manage aggregate mobility of multiple IP-enabled devices on-board a Low Earth Orbit satellite (a mobile network on-board). NEMO protocols enjoy several performance advantages, such as reduced signaling, increased manageability and conservation of satellite link bandwidth as compared to host mobility protocols for individual devices.
Abstract Due to inconsistent atmospheric conditions, scattering and scintillation of free space optical (FSO) signal can occur, thus negatively influencing the received signal intensity. The channel is usually modeled as a normalized... more
Abstract Due to inconsistent atmospheric conditions, scattering and scintillation of free space optical (FSO) signal can occur, thus negatively influencing the received signal intensity. The channel is usually modeled as a normalized fading coefficient with additive Gaussian noise. Optimal detection of the received signal is designed based on a decision rule, eg, Maximum Likelihood (ML), assuming the receiver knows the noise statistics and fading correlation of the channel.
Abstract: TCP was designed for wireline networks, where loss events are mostly caused by network congestion. The congestion control mechanism of current TCP uses loss events as the indicator of congestion, and reduces its congestion... more
Abstract: TCP was designed for wireline networks, where loss events are mostly caused by network congestion. The congestion control mechanism of current TCP uses loss events as the indicator of congestion, and reduces its congestion window size. However, when a lossy link is involved in a TCP connection, non-congestion random losses should also be considered. The congestion window size should not be decreased if a loss event is caused by link corruptions.
Abstract HTTP (Hyper Text Transfer Protocol) and TCP (Transmission Control Protocol) are usually used to retrieve objects in the Internet. Stream Control Transmission Protocol (SCTP) has attractive multi-streaming feature, which allows... more
Abstract HTTP (Hyper Text Transfer Protocol) and TCP (Transmission Control Protocol) are usually used to retrieve objects in the Internet. Stream Control Transmission Protocol (SCTP) has attractive multi-streaming feature, which allows for independent delivery among streams, thus can avoid the head-of-line blocking experienced by TCP and reduce the mean response time of users.
Abstract The availability of Channel State Information (CSI) at the receiver side of a Free Space Optical (FSO) link is required for optimal detection and diversity combining. Consequently, providing instantaneous CSI knowledge introduces... more
Abstract The availability of Channel State Information (CSI) at the receiver side of a Free Space Optical (FSO) link is required for optimal detection and diversity combining. Consequently, providing instantaneous CSI knowledge introduces challenges to receiver design and an increase in estimation error and bandwidth waste. In this work we investigate two selection-combining diversity schemes and their achieved gains when perfect instantaneous CSI is not available.
ABSTRACT Incoherent receivers of Free Space Optical (FSO) signals have no knowledge of instantaneous channel state. Thus, the receiver requires some information about the noise and fading statistics for a maximum likelihood (ML)-based... more
ABSTRACT Incoherent receivers of Free Space Optical (FSO) signals have no knowledge of instantaneous channel state. Thus, the receiver requires some information about the noise and fading statistics for a maximum likelihood (ML)-based optimal detection. Using pilot-aided symbols, we develop a simple multi slot averaging (MSA) estimation technique to approximate the values of parameters required at the incoherent detector.
Abstract Because of the statistical multiplexing of a large number of sources in an ATM network, it is not possible to eliminate cell losses due to buffer overflows. Several space priority mechanisms have been proposed in the literature... more
Abstract Because of the statistical multiplexing of a large number of sources in an ATM network, it is not possible to eliminate cell losses due to buffer overflows. Several space priority mechanisms have been proposed in the literature to manage buffers in the case of congestion. The aim of this paper is to establish buffer dimensioning criteria for the no-priority and the pushout space priority schemes under a broad range of input traffic parameters for a given QoS requirement.
WSNs typically comprise of sensing nodes with limited computational capability and onboard power. The sensed data in a WSN is transmitted from an individual node to a network sink in a multi-hop fashion. Since transmission costs are often... more
WSNs typically comprise of sensing nodes with limited computational capability and onboard power. The sensed data in a WSN is transmitted from an individual node to a network sink in a multi-hop fashion. Since transmission costs are often several orders of magnitude larger than computational costs, the efficiency of the WSN can be improved by in-network data aggregation techniques.
Abstract Communication is vital in order to coordinate rescue and clean up efforts should an event eliminate the most common infrastructure, such a cell tower and phone lines, in a region. One of the most effective ways to set up an... more
Abstract Communication is vital in order to coordinate rescue and clean up efforts should an event eliminate the most common infrastructure, such a cell tower and phone lines, in a region. One of the most effective ways to set up an alternative communication system without relying on traditional methods would be to attach a temporary system to airships floating above the region. However, an inherent problem with airships is keeping them in the desired area with the correct orientation.
Abstract The term mobile FSO refers to wireless optical nodes with mobility capabilities. Mobile FSO has emerged as a way to combat some of limitations facing FSO links, ie incompatibility of transmitters and receivers relative to... more
Abstract The term mobile FSO refers to wireless optical nodes with mobility capabilities. Mobile FSO has emerged as a way to combat some of limitations facing FSO links, ie incompatibility of transmitters and receivers relative to movement and misalignment. In this paper we utilize an angular diversity model for characterizing the performance of mobile FSO over atmospheric turbulence.
Abstract Existing terminal oriented handover mechanisms capable of meeting the strict delay bounds of real time applications such as VoIP do not consider the QoS of candidate handover networks. In this paper ECHO-a QoS based handover... more
Abstract Existing terminal oriented handover mechanisms capable of meeting the strict delay bounds of real time applications such as VoIP do not consider the QoS of candidate handover networks. In this paper ECHO-a QoS based handover solution for VoIP-is proposed. ECHO is endpoint centric and does not require any network support; it leverages the SCTP transport protocol. ECHO incorporates network metrics that directly affect VoIP quality into the handover decision process.
Page 1. 1 Dr. Mohammed Atiquzzaman atiq@ou.edu; http://www.cs.ou.edu/~atiq/ Running Integrated Services over Differentiated Service Networks: Quantitative Performance Measurements Mohammed Atiquzzaman University of Oklahoma Haowei Bai... more
Page 1. 1 Dr. Mohammed Atiquzzaman atiq@ou.edu; http://www.cs.ou.edu/~atiq/ Running Integrated Services over Differentiated Service Networks: Quantitative Performance Measurements Mohammed Atiquzzaman University of Oklahoma Haowei Bai Honeywell Aerospace William Ivancic NASA Glenn Research Center August 1, 2002 Boston, Massachusetts USA Page 2. 2 Dr.
Wireless channels have a high channel bit error rate and limited bandwidth. The high bit error rate degrades the quality of multimedia transmission, and also increases the buffer size requirement at the client. In this paper, we propose a... more
Wireless channels have a high channel bit error rate and limited bandwidth. The high bit error rate degrades the quality of multimedia transmission, and also increases the buffer size requirement at the client. In this paper, we propose a novel selective retransmission scheme for multimedia transmission over wireless ATM networks using the ABR service. Our objective is to develop a simple cost effective scheme which offers quality of service for MPEG compressed video transmitted over a noisy wireless channel.
Abstract Mobility protocols are designed to support handover between different wireless networks. Many of them suffer problems such as high handover latency, high packet overhead, high packet loss during handoff, lack of application... more
Abstract Mobility protocols are designed to support handover between different wireless networks. Many of them suffer problems such as high handover latency, high packet overhead, high packet loss during handoff, lack of application transparency, etc. To remove these problems, we proposed a network layer based mobility protocol framework, SEamless MObility using shim6 (SEMO6), for host mobility. It is based on using the SHIM6 protocol and provides multihoming, mobility and application transparency.
Abstract Node mobility has a direct impact on the performance evaluation of various network mobility protocols. Unfortunately, most of the analysis on mobility protocols used Random Waypoint mobility model which does not represent... more
Abstract Node mobility has a direct impact on the performance evaluation of various network mobility protocols. Unfortunately, most of the analysis on mobility protocols used Random Waypoint mobility model which does not represent real-world movement patterns of mobile nodes. In this paper, we have analyzed City Section mobility model, a realistic mobility model for the movement in the city streets.
Abstract The Internet Engineering Task Force (IETF) has defined the integrated services model for supporting real-time services. Guaranteed service is one of these services with firm delay and bandwidth guarantees. Before setting up a... more
Abstract The Internet Engineering Task Force (IETF) has defined the integrated services model for supporting real-time services. Guaranteed service is one of these services with firm delay and bandwidth guarantees. Before setting up a guaranteed service flow, traffic parameters of the source have to be specified in terms of token bucket traffic descriptors. The source must conform to these descriptors by shaping its traffic.
Available bit rate (ABR) is an emerging asynchronous transfer mode (ATM)-based telecommunication service, which dynamically allocates bandwidth to the users according to the available bandwidth in the network. However, research shows that... more
Available bit rate (ABR) is an emerging asynchronous transfer mode (ATM)-based telecommunication service, which dynamically allocates bandwidth to the users according to the available bandwidth in the network. However, research shows that ABR-based connections suffer from congestion at LAN–ATM gateway when ATM network abruptly reduces the bandwidth available to the gateway. Gateway congestion may result in high packet loss.
Abstract Multistage interconnection networks (MINs) are used to connect processors and memories in large-scale multiprocessor systems. MINs have also been proposed as switching fabrics in ATM networks. A MIN consists of several stages of... more
Abstract Multistage interconnection networks (MINs) are used to connect processors and memories in large-scale multiprocessor systems. MINs have also been proposed as switching fabrics in ATM networks. A MIN consists of several stages of small crossbar switching elements (SEs).
Abstract Even if a line-of-sight condition of Free Space Optics (FSO) is satisfied, atmospheric-induced fading, scattering, and attenuation may severely deteriorate the availability of the communication link. This argument is true except... more
Abstract Even if a line-of-sight condition of Free Space Optics (FSO) is satisfied, atmospheric-induced fading, scattering, and attenuation may severely deteriorate the availability of the communication link. This argument is true except in reconfigurable FSO ad hoc networks, a path reconfiguration scheme replaces a severed FSO link with an operational one. Reconfigurability, as a property of our hybrid FSO/RF (Radio Frequency) work in progress, provides connection reliability and network throughput.
Abstract Differentiated services (DiffServ) networks use two type of routers: edge routers mark the packet headers according to their service profile, while the core routers implement queue management to provide service differentiation... more
Abstract Differentiated services (DiffServ) networks use two type of routers: edge routers mark the packet headers according to their service profile, while the core routers implement queue management to provide service differentiation between packets according to information in their packet headers. Most previous studies on the performance of DiffServ have considered either the effect of the edge marking scheme or the effect of core queue management on the throughput of TCP applications.
The problem of monitoring and characterizing network traffic arises in the context of a variety of network management functions. For example, consider the five functions defined in the OSI Network Management Framework [20.1], ie,... more
The problem of monitoring and characterizing network traffic arises in the context of a variety of network management functions. For example, consider the five functions defined in the OSI Network Management Framework [20.1], ie, configuration management, performance management, fault management, accounting management and security management.
Abstract Mobile IP and SIGMA are handoff schemes at the network layer and the transport layer respectively. SIGMA is based on IP diversity and aims to improve the handoff performance over mobile IP by reducing the handoff latency. We... more
Abstract Mobile IP and SIGMA are handoff schemes at the network layer and the transport layer respectively. SIGMA is based on IP diversity and aims to improve the handoff performance over mobile IP by reducing the handoff latency. We compared the performance of the handoff schemes in an experimental test bed. Results show that SIGMA has a lower handoff latency when compared to mobile IP. Moreover, SIGMA can achieve a seamless handoff between two subnets.
Abstract To increase the availability of free space network (FSO) networks, the optical link is provided with a redundant backup network, such as RF, to form a hybrid network. The immediate switching from FSO to RF in hybrid networks... more
Abstract To increase the availability of free space network (FSO) networks, the optical link is provided with a redundant backup network, such as RF, to form a hybrid network. The immediate switching from FSO to RF in hybrid networks leads to suboptimal utilization of FSO network. In this work, a network of hybrid nodes, where each node is equipped with multiple transceivers and has multiple associations with other nodes of the network is proposed.
Abstract Studies have shown that the IETF recommended active queue management scheme, random early detection (RED) suffers from low throughput, large delay/jitter, and induces instability in networks. To improve the throughput and delay... more
Abstract Studies have shown that the IETF recommended active queue management scheme, random early detection (RED) suffers from low throughput, large delay/jitter, and induces instability in networks. To improve the throughput and delay of the RED gateways, double slope RED (DSRED) was proposed and was shown to outperform RED in a homogeneous TCP/IP network. The objective of this paper is to evaluate DSRED in a heterogeneous network environment.
Abstract TCP has been found to perform poorly in the presence of spurious timeouts (ST) caused by delay spikes which are especially more frequent in today's wireless mobile networks than in traditional wired network. Because STs are... more
Abstract TCP has been found to perform poorly in the presence of spurious timeouts (ST) caused by delay spikes which are especially more frequent in today's wireless mobile networks than in traditional wired network. Because STs are generally considered to represent a transient state in wired networks, previous research did not consider the effects of ST on the steady state performance of TCP.
Abstract The low pass filter (LPF) algorithm, which is used to calculate the average queue length in the random early detection (RED) algorithm, results in a poor response time when RED recovers from congestion. In this paper, we propose... more
Abstract The low pass filter (LPF) algorithm, which is used to calculate the average queue length in the random early detection (RED) algorithm, results in a poor response time when RED recovers from congestion. In this paper, we propose a new algorithm, called low pass filter/over drop avoidance (LPF/ODA), to improve the response time of RED. LPF/ODA is based on reducing the time required by RED to recover from long-term congestion.
Characteristics of wireless sensor networks, specifically dense deployment, limited processing power, and limited power supply, provide unique design challenges at the transport layer. Message transmission between sensor nodes over a... more
Characteristics of wireless sensor networks, specifically dense deployment, limited processing power, and limited power supply, provide unique design challenges at the transport layer. Message transmission between sensor nodes over a wireless medium is especially expensive. Care must be taken to design an efficient transport layer protocol that combines reliable message delivery and congestion control with minimal overhead and retransmission. Sensor networks are created using low cost, low power nodes.
Network centric handover solutions for all IP wireless networks usually require modifications to network infrastructure which can stifle any potential rollout. This has led researchers to begin looking at alternative approaches. Endpoint... more
Network centric handover solutions for all IP wireless networks usually require modifications to network infrastructure which can stifle any potential rollout. This has led researchers to begin looking at alternative approaches. Endpoint centric handover solutions do not require network infrastructure modification, thereby alleviating a large barrier to deployment.
Mobile IP to handle mobility of Internet hosts at the network layer. Mobile IP, however, suffers from a number of drawbacks such as high handover latency, packet loss, and conflict with network security solutions. In this paper, we... more
Mobile IP to handle mobility of Internet hosts at the network layer. Mobile IP, however, suffers from a number of drawbacks such as high handover latency, packet loss, and conflict with network security solutions. In this paper, we describe TraSH, a new Transport Layer Seamless Handover solution to mobility. TraSH utilizes multi-homing to achieve a seamless handover of a mobile host, and is designed to solve many of the drawbacks of Mobile IP.
Abstract Network mobility (NEMO) handles mobility of a set of mobile nodes in an aggregate way using one or more mobile routers. NEMO introduces several advantages, such as reduced signaling, increased manageability, reduced power... more
Abstract Network mobility (NEMO) handles mobility of a set of mobile nodes in an aggregate way using one or more mobile routers. NEMO introduces several advantages, such as reduced signaling, increased manageability, reduced power consumption and conservation of bandwidth when compared to individual host mobility. NEMO Basic Support Protocol (BSP), the IETF standard for NEMO, suffers from a number of limitations, like inefficient route and increased handoff latency.
Abstract—The Internet Engineering Task Force has developed Mobile IP to handle mobility of Internet hosts at the network layer. Spacecrafts in space are analogous to mobile nodes in the terrestrial network. NASA has been experimenting... more
Abstract—The Internet Engineering Task Force has developed Mobile IP to handle mobility of Internet hosts at the network layer. Spacecrafts in space are analogous to mobile nodes in the terrestrial network. NASA has been experimenting with Mobile IP to handle handoffs in space networks. Mobile IP, however, suffers from a number of drawbacks such as high handoff latency, packet loss, and interoperability issues with network security solutions.
This study deals with the Delay-Constrained Capacitated Minimum Spanning Tree (DC-CMST) problem arising in topology discovery of local network. While the traditional Capacitated Minimum Spanning Tree (CMST) problem deals with only traffic... more
This study deals with the Delay-Constrained Capacitated Minimum Spanning Tree (DC-CMST) problem arising in topology discovery of local network. While the traditional Capacitated Minimum Spanning Tree (CMST) problem deals with only traffic capacity constraint of a port of a source node, and Delay-Constrained Minimum Spanning Tree (DCMST) considers only the maximum end-to-end delay constraint, the DC-CMST problem deals with mean network delay and traffic capacity constraints simultaneously.
Abstract—Stream Control Transmission Protocol (SCTP) is a new transport layer protocol which can be deployed in the Internet along with TCP. In this paper, we investigate the performance issues that arise when SCTP and TCP are used in the... more
Abstract—Stream Control Transmission Protocol (SCTP) is a new transport layer protocol which can be deployed in the Internet along with TCP. In this paper, we investigate the performance issues that arise when SCTP and TCP are used in the same satellite network. We evaluate performance through measurement of throughput, and also fairness of use of networks resources by the two protocols. We observed that SCTP is fair, although SCTP always achieved slightly higher throughput than TCP.
ABSTRACT Low Earth Orbit (LEO) satellites will work as an important component in future data communication networks. LEO satellites provide low end-toend delays and efficient frequency spectrum utilization, making them suitable for... more
ABSTRACT Low Earth Orbit (LEO) satellites will work as an important component in future data communication networks. LEO satellites provide low end-toend delays and efficient frequency spectrum utilization, making them suitable for personal communication. However, due to high satellite speed, ongoing communication using LEO constellations experiences frequent handover. In this article we provide an up-to-date, comprehensive literature survey on proposed handover schemes for LEO satellite systems.
Abstract Mobility of Internet hosts allows computing nodes to move between subnets. Mobility can be handled at different layers of the protocol stack, with network and transport layer mobility being the most widely studied. Transport... more
Abstract Mobility of Internet hosts allows computing nodes to move between subnets. Mobility can be handled at different layers of the protocol stack, with network and transport layer mobility being the most widely studied. Transport layer mobility can overcome many of the limitations of network layer schemes like mobile IP. Various approaches have been proposed to implement mobility in the transport layer.
Abstract—Mobile IP has been developed to handle mobility of Internet hosts at the network layer. Mobile IP suffers from a number of drawbacks such as requirement of infrastructure change, high handover latency, high packet loss rate, and... more
Abstract—Mobile IP has been developed to handle mobility of Internet hosts at the network layer. Mobile IP suffers from a number of drawbacks such as requirement of infrastructure change, high handover latency, high packet loss rate, and conflict with network security solutions. In this paper, we describe the architecture of Seamless IP diversity-based Generalized Mobility Architecture (SIGMA)-a new mobility management scheme.
Abstract Network system designers need to understand the error performance of wireless mobile channels in order to improve the quality of communications by deploying better modulation and coding schemes, and better network architectures.... more
Abstract Network system designers need to understand the error performance of wireless mobile channels in order to improve the quality of communications by deploying better modulation and coding schemes, and better network architectures. It is also desirable to have an accurate and thoroughly reproducible error model, which would allow network designers to evaluate a protocol or algorithm and its variations in a controlled and repeatable way.
ABSTRACT IETF has proposed Mobile IPv6-based Network Mobility (NEMO) basic support protocol (BSP) to support network mobility. NEMO BSP inherits all the drawbacks of Mobile IPv6, such as inefficient routing path, single point of failure,... more
ABSTRACT IETF has proposed Mobile IPv6-based Network Mobility (NEMO) basic support protocol (BSP) to support network mobility. NEMO BSP inherits all the drawbacks of Mobile IPv6, such as inefficient routing path, single point of failure, high handover latency and packet loss, and high packet overhead. To address these drawbacks, we proposed an IP diversity-based network mobility management scheme called Seamless IP-diversity based NEtwork MObility (SINEMO).
Abstract The stream control transmission protocol (SCTP) has recently been standardized as a new transport layer protocol in the IP suite. In addition to the core features of TCP, SCTP incorporates a number of advanced and unique features... more
Abstract The stream control transmission protocol (SCTP) has recently been standardized as a new transport layer protocol in the IP suite. In addition to the core features of TCP, SCTP incorporates a number of advanced and unique features which are not available in TCP. The paper investigates the suitability of SCTP for data communications over satellite links. We describe SCTP features that allow SCTP to utilize the bandwidth of satellite networks better, while at the same time avoiding congestion collapse in a shared network.
Abstract Mobile IP is the IETF-proposed standard to offer seamless mobile computing. A new transport layer protocol, called stream control transmission protocol (SCTP), has recently been accepted by IETF as a proposed standard to address... more
Abstract Mobile IP is the IETF-proposed standard to offer seamless mobile computing. A new transport layer protocol, called stream control transmission protocol (SCTP), has recently been accepted by IETF as a proposed standard to address a number of TCP limitations. Most of the previous research on end-to-end throughput over Mobile IP has been carried out on TCP-Reno. Both TCP and SCTP can use selective acknowledgment (SACK) for error recovery.
Abstract Mobile IP has been developed to handle mobility of Internet hosts at the network layer. Mobile IP (MIP), however, suffers from a number of drawbacks such as requirement of infrastructure change, high handover latency, high packet... more
Abstract Mobile IP has been developed to handle mobility of Internet hosts at the network layer. Mobile IP (MIP), however, suffers from a number of drawbacks such as requirement of infrastructure change, high handover latency, high packet loss rate, and conflict with network security solutions. In this paper, we describe and evaluate the performance of SIGMA, a Seamless IP diversity-based Generalized Mobility Architecture.
Abstract Random early detection (RED), an active queue management scheme, has been proposed by the Internet Engineering Task Force (IETF) to improve the throughput of TCP/IP based networks in the next generation routers. RED has a number... more
Abstract Random early detection (RED), an active queue management scheme, has been proposed by the Internet Engineering Task Force (IETF) to improve the throughput of TCP/IP based networks in the next generation routers. RED has a number of problems such as low throughput, large delay/jitter and inducing instability in networks. Previous enhancements to RED attempted to improve the performance of RED by modifying the parameters of RED. However such modifications result in limited improvement.
Abstract The Internet Engineering Task Force has developed Mobile IP to handle the mobility of Internet hosts at the network layer. Mobile IP, however, suffers from a number of drawbacks such as high handover latency, packet loss, and... more
Abstract The Internet Engineering Task Force has developed Mobile IP to handle the mobility of Internet hosts at the network layer. Mobile IP, however, suffers from a number of drawbacks such as high handover latency, packet loss, and conflict with network security solutions. We describe and evaluate the performance of SIGMA (seamless IP diversity based generalized mobility architecture).
Abstract The stream control transmission protocol (STCP) is being standardized by the IEFT as a reliable transport protocol to transport SS7signaling messages over IP networks. Due to its attractive features such as multistreaming and... more
Abstract The stream control transmission protocol (STCP) is being standardized by the IEFT as a reliable transport protocol to transport SS7signaling messages over IP networks. Due to its attractive features such as multistreaming and multihoming, SCTP has received much attention from the network community, in terms of both research and development. This article introduces the main features of SCTP, and discusses the state of the art in SCTP research and development activities.
Abstract The rapid proliferation of the Internet has given rise to a strong interest in carrying telephony over the Internet. Because the Internet supports data communications, a range of other services can be bundled together with... more
Abstract The rapid proliferation of the Internet has given rise to a strong interest in carrying telephony over the Internet. Because the Internet supports data communications, a range of other services can be bundled together with Internet telephony. The Internet, however, was designed for non-real-time data communications, and hence it poses several technical challenges that must be overcome before the Internet can be successfully used for carrying telephone services.
Supporting analog RF signal transmission over optical fibers, this project demonstrates a successful application of wavelength division multiplexing (WDM) to the avionics environment. We characterize the simultaneous transmission of four... more
Supporting analog RF signal transmission over optical fibers, this project demonstrates a successful application of wavelength division multiplexing (WDM) to the avionics environment. We characterize the simultaneous transmission of four RF signals (channels) over a single optical fiber. At different points along a fiber optic backbone, these four analog channels are sequentially multiplexed and demultiplexed to more closely emulate the conditions in existing onboard aircraft.
Abstract Eifel has been proposed as a solution to enhance the performance of TCP during delay spikes in a wireless mobile environment. This paper evaluates and compares the performance of SCTP, TCP, and Eifel during delay spikes. We have... more
Abstract Eifel has been proposed as a solution to enhance the performance of TCP during delay spikes in a wireless mobile environment. This paper evaluates and compares the performance of SCTP, TCP, and Eifel during delay spikes. We have shown that although Eifel performs better than TCP Reno and SCTP when there are no packet losses, the opposite is true when packets are lost in the presence of delay spikes.
When the Hough transform is applied to the detection of straight lines in images, it provides the parameters but not the length or the end points of the line. We propose a new algorithm for the determination of the length and the end... more
When the Hough transform is applied to the detection of straight lines in images, it provides the parameters but not the length or the end points of the line. We propose a new algorithm for the determination of the length and the end points of a line in an image. It is very efficient in terms of computing time and does not depend on the sharpness of the peak in the accumulator array.
Abstract Multistage interconnection networks (MIN) are used to connect processors to memories in shared memory multiprocessor systems. A generalized Markov chain model for the performance evaluation of a single-buffered Omega network, in... more
Abstract Multistage interconnection networks (MIN) are used to connect processors to memories in shared memory multiprocessor systems. A generalized Markov chain model for the performance evaluation of a single-buffered Omega network, in the presence of a hot spot, is proposed. The proposed model produces better results than existing models
Abstract The cost effective ABR service is suitable for transmitting bursty compressed video over ATM network. Here, we propose a fast buffer fillup (FBF) scheme to run VoD over ATM network with ABR service. We develop models to determine... more
Abstract The cost effective ABR service is suitable for transmitting bursty compressed video over ATM network. Here, we propose a fast buffer fillup (FBF) scheme to run VoD over ATM network with ABR service. We develop models to determine buffer size at the client and the server for our scheme. We also develop relationships between the startup delay, the ABR service parameters, and the network congestion status. Our results indicate that the new scheme minimizes the startup delay and has simple network resource requirements
The emerging, ATM network will support permanent, semi-permanent and switched virtual channel connections (SVCC). A number of simulation studies have been carried out to study the performance of SVCCs using empirical data. The absence of... more
The emerging, ATM network will support permanent, semi-permanent and switched virtual channel connections (SVCC). A number of simulation studies have been carried out to study the performance of SVCCs using empirical data. The absence of an analytical model has prevented the study of SVCCs under known traffic distributions. In this paper, we develop a new< I> delayed vacation</I> model to facilitate the performance study of SVCCs with configurable inactivity timer in the ATM network interface card (NIC).
Abstract The Hough transform is used to detect patterns in images. Its advantage is the ability to detect discontinuous patterns in noisy images. The drawback is its demand for a large amount of computing power. Efficient algorithms and... more
Abstract The Hough transform is used to detect patterns in images. Its advantage is the ability to detect discontinuous patterns in noisy images. The drawback is its demand for a large amount of computing power. Efficient algorithms and their implementations in multiprocessor systems have been proposed to overcome the computational requirements.
Abstract For uniform traffic, ATM switches employing shared buffering have lower cell loss probability and better buffer utilization than other buffering strategies. However, the performance of shared-buffer switches degrades dramatically... more
Abstract For uniform traffic, ATM switches employing shared buffering have lower cell loss probability and better buffer utilization than other buffering strategies. However, the performance of shared-buffer switches degrades dramatically under non-uniform traffic. Traffic nonuniformity is inherent in telecommunications, and is likely to be present in ATM networks because of the different characteristics of traffic sources such as video, voice and data.
Abstract Multimedia is an emerging service which integrates voice, video and data in the same service. With the progress made in high speed large capacity multimedia servers, high speed networks, cost effective QoS, acceptable service... more
Abstract Multimedia is an emerging service which integrates voice, video and data in the same service. With the progress made in high speed large capacity multimedia servers, high speed networks, cost effective QoS, acceptable service category and cost effective set top boxes, it is currently possible to carry multimedia over high speed networks cost effectively and efficiently. This paper surveys the progress made and the future of efficiently carrying multimedia over ATM networks
Abstract Previous models for performance evaluation of multistage switches have been neither accurate enough nor based on realistic assumptions regarding the correlation of the blocked cells in successive stages of the switch. In this... more
Abstract Previous models for performance evaluation of multistage switches have been neither accurate enough nor based on realistic assumptions regarding the correlation of the blocked cells in successive stages of the switch. In this paper, a new analytical model which permits an accurate analysis of multistage switches is proposed. The new model reflects the behavior of blocked cells, and takes into account the fact that a blocked cell always hunts for the same output link in successive cycles
A number of distributed corporate intranets can be connected together using the ABR service of an ATM network to form a virtual private network. However, because the available bandwidth of the ABR connection may be occasionally reduced by... more
A number of distributed corporate intranets can be connected together using the ABR service of an ATM network to form a virtual private network. However, because the available bandwidth of the ABR connection may be occasionally reduced by the ATM network, severe congestion may occur at the gateway connecting an intranet to the ATM network. Such congestion is likely to cause packet loss at the gateway which in turn may significantly reduce the throughput of intranet applications.
Abstract A model for the analysis of ATM switches based on shared buffer switching for broadband ISDN networks is developed, and the results are compared with simulation. Switches constructed from shared buffer switching elements (SE) no... more
Abstract A model for the analysis of ATM switches based on shared buffer switching for broadband ISDN networks is developed, and the results are compared with simulation. Switches constructed from shared buffer switching elements (SE) no longer suffer from the head of line blocking which is a common problem in simple input buffering. The analysis models the state of the entire switch and extends the model introduced by Turner (see International Teletraffic Congress, Copenhagen, Denmark, p.
The NASA STI Program Office is operated by Langley Research Center, the Lead Center for NASA's scientific and technical information. The NASA STI Program Office provides access to the NASA STI Database, the largest collection of... more
The NASA STI Program Office is operated by Langley Research Center, the Lead Center for NASA's scientific and technical information. The NASA STI Program Office provides access to the NASA STI Database, the largest collection of aeronautical and space science STI in the world. The Program Office is also NASA's institutional mechanism for disseminating the results of its research and development activities. These results are published by NASA in the NASA STI Report Series, which includes the following report types:
Abstract The throughput degradation of transport control protocol (TCP) over lossy links due to the coexistence of congestion losses and link corruption losses is very similar to the degradation of processor performance due to control... more
Abstract The throughput degradation of transport control protocol (TCP) over lossy links due to the coexistence of congestion losses and link corruption losses is very similar to the degradation of processor performance due to control hazards in CPU design. First, two types of loss events in networks with lossy links can be considered as two possibilities of a branching result (correct speculation vs. incorrect speculation) in a CPU.
Abstract Multistage interconnection networks based on shared buffering are known to have better performance and buffer utilization than input or output buffered switches. Shared buffer switches do not suffer from head of line blocking... more
Abstract Multistage interconnection networks based on shared buffering are known to have better performance and buffer utilization than input or output buffered switches. Shared buffer switches do not suffer from head of line blocking which is a common problem in simple input buffering. Shared buffer switches have previously been studied under uniform and unbalanced traffic patterns.
Abstract The degradation of transport control protocol (TCP) throughput in networks with lossy links is mainly due to the coexistence of two types of losses, congestion losses and link corruption losses. This is very similar to processor... more
Abstract The degradation of transport control protocol (TCP) throughput in networks with lossy links is mainly due to the coexistence of two types of losses, congestion losses and link corruption losses. This is very similar to processor performance degradation due to control hazards in CPU design. First, two types of loss events in networks with lossy links can be considered as two possibilities of a branching result (correct speculation vs. incorrect speculation) in a CPU.
Abstract The authors have developed an exact model to evaluate the performance of multistage interconnection networks using internal shared buffering. The model assumes general output distribution which enables one to study the... more
Abstract The authors have developed an exact model to evaluate the performance of multistage interconnection networks using internal shared buffering. The model assumes general output distribution which enables one to study the performance of such networks under any desired output distribution. Among many possible output distributions, uniform, hot spot and favorite distributions are used as examples. The model is validated by the comparison of numerical results with event simulation results
Random Early Detection (RED), an active queue management scheme, has been recommended by the Internet Engineering Task Force (IETF) for the next generation routers. RED suffers from a number of performance problems, such as low... more
Random Early Detection (RED), an active queue management scheme, has been recommended by the Internet Engineering Task Force (IETF) for the next generation routers. RED suffers from a number of performance problems, such as low throughput, large delay/jitter, and induces instability in networks. Many of the previous attempts to improve the performance of RED have been based on optimizing the values of the RED parameters.
Abstract A new and accurate Markov chain model for evaluating the performance of multistage ATM switching fabrics with 2× 2 finite output-buffered switching elements is proposed. By comparing the results obtained from the proposed model,... more
Abstract A new and accurate Markov chain model for evaluating the performance of multistage ATM switching fabrics with 2× 2 finite output-buffered switching elements is proposed. By comparing the results obtained from the proposed model, existing models, and simulations, it has been shown that the proposed model is much more accurate than existing models in the presence of a non-uniform traffic in the switch.
Shared buffer switches do not suffer from head of line blocking which is a common problem in simple input buffering. Shared buffer switches have previously been studied under uniform and unbalanced traffic patterns. However, due to the... more
Shared buffer switches do not suffer from head of line blocking which is a common problem in simple input buffering. Shared buffer switches have previously been studied under uniform and unbalanced traffic patterns. However, due to the complexity of the model, it was not possible to fully explore the performance of such a switch, in the presence of a single hot spot. In this paper, we develop a new model for an ATM switch constructed from shared buffered switching elements, and operating under a hot spot traffic pattern.
Abstract We analyse the cost performance of LAN interconnection over ATM using switched VC. Frame loss due to bu er over ow during connection setup has been taken into consideration in the proposed cost function. We investigate the e ect... more
Abstract We analyse the cost performance of LAN interconnection over ATM using switched VC. Frame loss due to bu er over ow during connection setup has been taken into consideration in the proposed cost function. We investigate the e ect of the length of the holding time of an idle VC on the total cost per frame transmitted. Our simulation results suggest that there is no optimum holding time for minimising the total cost.
Abstract LAN interconnection is expected to be the rst service o ered by ATM based B-ISDN. Since tra c on the current LANs is connectionless and bursty, the main challenge will be to provide an e cient connectionless service over... more
Abstract LAN interconnection is expected to be the rst service o ered by ATM based B-ISDN. Since tra c on the current LANs is connectionless and bursty, the main challenge will be to provide an e cient connectionless service over connection oriented ATM network. One of the methods proposed for transporting bursty LAN tra c over ATM is to set up an ATM connection upon arrival of a burst and close the connection while there is no tra c. We investigate the performance of such method of LAN interconnection.
Abstract Because of the growing investment in both IP and ATM networks, designing efficient IP-ATM gateways for interconnecting these two networks has become very important. One of the main design issues is buffer dimensioning at the... more
Abstract Because of the growing investment in both IP and ATM networks, designing efficient IP-ATM gateways for interconnecting these two networks has become very important. One of the main design issues is buffer dimensioning at the gateway for optimum performance. Modeling IP-ATM gateways helps obtaining the optimum design. However, due to very complex nature of an IP-ATM gateway, only models for gateways with infinite buffers have been studied previously.
Abstract. This study deals with the topology discovery for the capacitated minimum spanning tree network. The problem is composed of finding the best way to link nodes to a source node and, in graph-theoretical terms, it is to determine a... more
Abstract. This study deals with the topology discovery for the capacitated minimum spanning tree network. The problem is composed of finding the best way to link nodes to a source node and, in graph-theoretical terms, it is to determine a minimal spanning tree with a capacity constraint. In this paper, a heuristic algorithm with two phases is presented. Computational complexity analysis and simulation confirm that our algorithm produces better results than the previous other algorithms in short running time.
ABSTRACT: Video-on-Demand in education is used in a very different way to entertainment video. In particular, it is much more interactive, requiring variations in bit rates over long periods. This paper explores some of the server and... more
ABSTRACT: Video-on-Demand in education is used in a very different way to entertainment video. In particular, it is much more interactive, requiring variations in bit rates over long periods. This paper explores some of the server and network design issues in implementing an ATM network to carry this interactive traffic. It includes an analysis of the effect of a server using the Winsock 2 quality of service mechanism and compares the system performance when CBR, UBR and VBR are used to carry interactive Video-on-Demand sessions.
ABSTRACT A Markov chain model for evaluating the performance of a multistage ATM switching fabric using split shared bu ered switch elements (SE) is proposed. By comparing the results obtained from the proposed model and simulations, it... more
ABSTRACT A Markov chain model for evaluating the performance of a multistage ATM switching fabric using split shared bu ered switch elements (SE) is proposed. By comparing the results obtained from the proposed model and simulations, it is shown that the model is accurate in the presence of uniform and non-uniform tra c in the switch. To eliminate the in uence of head of line blocking, a non-FIFO queueing discipline approach called a window by-pass mechanism is considered.
ABSTRACT In this paper, a new and e cient Markov chain model for evaluating the performance of ATM switching fabrics based on multistage switches with 2 2 nite output-bu ered SEs is proposed. By comparing the results obtained from the... more
ABSTRACT In this paper, a new and e cient Markov chain model for evaluating the performance of ATM switching fabrics based on multistage switches with 2 2 nite output-bu ered SEs is proposed. By comparing the results obtained from the proposed model, previous models and simulations, it has been shown that the proposed model is much more accurate than previous models in the presence of a non-uniform tra c in the switch.
ABSTRACT: It has been observed that the usage pattern of interactive video on demand (VOD) is significantly different to entertainment video. In particular, the usage pattern includes pausing, playing and fast-forwarding parts of the... more
ABSTRACT: It has been observed that the usage pattern of interactive video on demand (VOD) is significantly different to entertainment video. In particular, the usage pattern includes pausing, playing and fast-forwarding parts of the video sequence. This usage pattern results in highly interactive video on demand which in turn gives rise to multiscale burstiness of the traffic to be carried over the network.
Abstract Multiprocessor systems can provide higher performance, reliability, and availability than single processor systems. In order to properly assess the effectiveness of multiprocessor systems, measures that combine performance and... more
Abstract Multiprocessor systems can provide higher performance, reliability, and availability than single processor systems. In order to properly assess the effectiveness of multiprocessor systems, measures that combine performance and reliability are needed. Most previous studies have considered the performance and reliability/availability separately. Only a limited number of studies have been carried out by considering the performance and reliability together in the presence of a uniform traffic in the network.
An interactive video-on-demand (IVoD) system consists of a video server and a client connected together through a high speed network. Use of interactive video-on-demand in an educational environment is very interactive because students... more
An interactive video-on-demand (IVoD) system consists of a video server and a client connected together through a high speed network. Use of interactive video-on-demand in an educational environment is very interactive because students frequently pause, fast-forward, skip and view frame-by-frame. Designing a network able to support interactivity and make efficient use of bandwidth is challenging.
ABSTRACT A Mobile Network consists of a set of IP nodes that move collectively. A Low Earth Orbiting (LEO) satellite with on-board IP-enabled devices, such as telescopes, computers, etc., can be considered as a mobile network handing off... more
ABSTRACT A Mobile Network consists of a set of IP nodes that move collectively. A Low Earth Orbiting (LEO) satellite with on-board IP-enabled devices, such as telescopes, computers, etc., can be considered as a mobile network handing off between ground stations.
Abstract SIGMA is an IP diversity-based mobility management scheme that aims to reduce handoff latency and packet loss of mobile IP. In this paper, we propose a power-aware version of SIGMA (called PEARS) which reduces power consumption... more
Abstract SIGMA is an IP diversity-based mobility management scheme that aims to reduce handoff latency and packet loss of mobile IP. In this paper, we propose a power-aware version of SIGMA (called PEARS) which reduces power consumption by intelligently switching off network devices, and improves handoff performance by reducing the number of unnecessary handoffs. The effectiveness of PEARS and SIGMA have been evaluated on a Linux-based experimental testbed.
Abstract: In some recent papers, the reliability analyses for multistage interconnection networks (MIN) have been carried out with the assumption that the failed components are not repaired (replaced). However, in most practical cases a... more
Abstract: In some recent papers, the reliability analyses for multistage interconnection networks (MIN) have been carried out with the assumption that the failed components are not repaired (replaced). However, in most practical cases a faulty component would be repaired (replaced) within a certain period of time. In this paper, we determine the network reliability of MINs with component failures and normal replacement time, and determine the maximum allowable replacement time (MART) for a given reliability.
Multimedia is an emerging service which integrates voice, video and data in the same service. With the progress made in high speed large capacity multimedia servers, high speed networks, QoS, service guarantees and set top boxes, it is... more
Multimedia is an emerging service which integrates voice, video and data in the same service. With the progress made in high speed large capacity multimedia servers, high speed networks, QoS, service guarantees and set top boxes, it is currently possible to cost effectively and efficiently carry multimedia over high speed networks. This paper surveys the progress made, and the future of efficiently carrying multimedia over the emerging Asynchronous Transfer Mode networks.
ABSTRACT Continued progress in both civil and military avionics applications is overstressing the capabilities of existing radio-frequency (RF) communication networks based on coaxial cables on board modern aircrafts. Future avionics... more
ABSTRACT Continued progress in both civil and military avionics applications is overstressing the capabilities of existing radio-frequency (RF) communication networks based on coaxial cables on board modern aircrafts. Future avionics systems will require high-bandwidth on-board communication links that are lightweight, immune to electromagnetic interference, and highly reliable. Fiber optic communication technology can meet all these challenges in a cost-effective manner.
Performance evaluation of multiple-bus multiprocessor systems is usually carried out under the assumption of uniform memory reference model. Hot spots arising in multiprocessor systems due to the use of shared variables, synchronization... more
Performance evaluation of multiple-bus multiprocessor systems is usually carried out under the assumption of uniform memory reference model. Hot spots arising in multiprocessor systems due to the use of shared variables, synchronization primitives, etc. give rise to non-uniform memory reference pattern. The objective of this paper is to study the performance of multiple bus multiprocessor system in the presence of hot spots.
abstract ATM is a connection oriented network while IP is based on a connectionless protocol. Connecting the two networks requires protocol conversion. When IP packets arrive at the interconnection between the two networks, signalling is... more
abstract ATM is a connection oriented network while IP is based on a connectionless protocol. Connecting the two networks requires protocol conversion. When IP packets arrive at the interconnection between the two networks, signalling is used to open a switched virtual circuit on the ATM side. In this paper, we look at the management of the ATM connection with a view to reducing the cost of the connection.
Abu S. Reaz, Mohammed Atiquzzaman Telecommunications and Networks Research Lab School of Computer Science, University of Oklahoma, Norman, OK 73019-6151, USA. Email:{sayeem reaz, atiq}@ ou. edu Keywords: Location Management, DNS, Mobility... more
Abu S. Reaz, Mohammed Atiquzzaman Telecommunications and Networks Research Lab School of Computer Science, University of Oklahoma, Norman, OK 73019-6151, USA. Email:{sayeem reaz, atiq}@ ou. edu Keywords: Location Management, DNS, Mobility Management, IP Diversity, Paging
Abstract A connection has to be opened before data can be transmitted over an ATM network. The connection can be permanent, semipermanent or switched. Depending of requirements, switched virtual circuits are dynamically set up and torn... more
Abstract A connection has to be opened before data can be transmitted over an ATM network. The connection can be permanent, semipermanent or switched. Depending of requirements, switched virtual circuits are dynamically set up and torn down using signalling. When a connection has to be reestablished, the network may reject the connection or may o er a connection with a reduced bandwidth.
Abstract Dedicated hardware can be used to release the CPU of an image processing system, of routine image pre-processing tasks, thereby speeding up the operational speed of the system. This paper describes the hardware implementation of... more
Abstract Dedicated hardware can be used to release the CPU of an image processing system, of routine image pre-processing tasks, thereby speeding up the operational speed of the system. This paper describes the hardware implementation of a one-pass fill, shrink and expand algorithm to clear random noise from an image. The three operations, comprising the algorithm, operate in parallel on a raster-scan image in a pipelined system.
Abstract Prefix delegation-based schemes have been proposed to solve the route optimization problem in NEtwork MObility where multiple IP-enabled hosts move together as a mobile network.
Abstract Performance evaluation of multiple-bus multiprocessor systems is usually carried out under the assumption of uniform memory reference model. The objective of this paper is to study the performance of multiple bus multiprocessor... more
Abstract Performance evaluation of multiple-bus multiprocessor systems is usually carried out under the assumption of uniform memory reference model. The objective of this paper is to study the performance of multiple bus multiprocessor system in the presence of hot spots. Analytical expressions for the average memory bandwidth and probability of acceptance of prioritized processors have been derived. Two new phenomenon, coined as bumping and knee effect, have been observed in the acceptance probabilities of the processors.
ABSTRACT When the Hough transform is applied to the detection of straight lines in images, it provides only the parameters of the line but not the length or the end points of the line. We propose a new algorithm for the determination of... more
ABSTRACT When the Hough transform is applied to the detection of straight lines in images, it provides only the parameters of the line but not the length or the end points of the line. We propose a new algorithm for the determination of the length and the end points of a line in an image. It is very e cient in terms of computing time and does not depend on the sharpness of the peak in the accumulator array.
Abstract The Hough transform is used to detect patterns in images. E cient algorithms and their implementations in multiprocessor systems have been proposed to overcome the computational requirements. An e cient pipelined implementation... more
Abstract The Hough transform is used to detect patterns in images. E cient algorithms and their implementations in multiprocessor systems have been proposed to overcome the computational requirements. An e cient pipelined implementation of the transform in a pyramid machine has been proposed. The proposed implementation considers task scheduling to ensure uniform computational load among the processor elements in the pyramid.
Abstract Connections in an ATM network are made using virtual channel connections which can be either permanent (PVCC) or switched (SVCC). SVCC requires a signalling protocol which is being standardised by international standards... more
Abstract Connections in an ATM network are made using virtual channel connections which can be either permanent (PVCC) or switched (SVCC). SVCC requires a signalling protocol which is being standardised by international standards organisations. Because of the cost e ectiveness of SVCCs over PVCCs for data communication in an ATM environment, a signicant amount of work has been carried out to determine the most cost-e cient and e ective ways to operate SVCCs.
Abstract During flight, aircraft avionics transmit and receive RF signals to/from antennas over coaxial cables. As the density and complexity of onboard avionics increases, the electromagnetic interference (EMI) environment degrades... more
Abstract During flight, aircraft avionics transmit and receive RF signals to/from antennas over coaxial cables. As the density and complexity of onboard avionics increases, the electromagnetic interference (EMI) environment degrades proportionately, leading to decreasing signal-to-noise ratios (SNRs) and potential safety concerns. The coaxial cables are inherently lossy, limiting the RF signal bandwidth while adding considerable weight.
Abstract—Mobile networks can be formed in vehicles, ships, satellites with a wide variety of on-board IP-enable devices. In spite of the fact that the connection configuration of the components inside the mobile network can influence its... more
Abstract—Mobile networks can be formed in vehicles, ships, satellites with a wide variety of on-board IP-enable devices. In spite of the fact that the connection configuration of the components inside the mobile network can influence its total cost and performance regarding mobility management, there exists no standard topological configuration of the mobile network. In this paper, we have performed a cost analysis of the key components of the nested mobile network considering all possible costs.
Abstract A highly parallel multiprocessor architecture for low-level processing of digital images is described in this paper. It is based on the ideas of distributed memory, data replication to reduce the need for interprocessor... more
Abstract A highly parallel multiprocessor architecture for low-level processing of digital images is described in this paper. It is based on the ideas of distributed memory, data replication to reduce the need for interprocessor communications, and dedicated links between processors to eliminate the need for a common bus for interprocessor communications.
Abstract—Mobile IP, an industry standard for handling mo-bility, suffers from high handover latency and packet loss, in addition to change in network infrastructure. To overcome these problems, we proposed a novel approach called Seamless... more
Abstract—Mobile IP, an industry standard for handling mo-bility, suffers from high handover latency and packet loss, in addition to change in network infrastructure. To overcome these problems, we proposed a novel approach called Seamless IP diversity based Generalized Mobility Architecture (SIGMA). Although SIGMA achieved a low latency handoff, use of IP diversity resulted in some instability during handoff. In this paper, we propose a new handoff policy, called HANSIG-HR, to solve the instability problem of SIGMA.
Abstract Retransmission ambiguity, arising from delay spikes in a wireless mobile environment, results in poor TCP performance. Eifel improves the performance of TCP by using the timestamp option, which requires additional header bytes,... more
Abstract Retransmission ambiguity, arising from delay spikes in a wireless mobile environment, results in poor TCP performance. Eifel improves the performance of TCP by using the timestamp option, which requires additional header bytes, resulting in increased overhead in bandwidth constrained wireless networks. Moreover, the destination needs to support the timestamp option.
Abstract In recent years there has been a strong interest in transmitting compressed Video over ATM. Previous work has dealt with transmitting MPEG over CBR and VBR services of ATM. The ABR service of ATM is expected to be much more cost... more
Abstract In recent years there has been a strong interest in transmitting compressed Video over ATM. Previous work has dealt with transmitting MPEG over CBR and VBR services of ATM. The ABR service of ATM is expected to be much more cost e ective than CBR or VBR. There has been a limited amount of work done in transmitting video over ABR. However, there hasn't been much work done on running client/server applications (for example, video on demand) over ABR.
Abstract Many of the existing analytical models for output buffered switching elements (SE) assume uniform traffic and infinite buffers at each output port of an SE. Moreover, because of simplifying assumptions, the results are not... more
Abstract Many of the existing analytical models for output buffered switching elements (SE) assume uniform traffic and infinite buffers at each output port of an SE. Moreover, because of simplifying assumptions, the results are not accurate. It is important to develop an accurate analytical model to tailor the design of the network parameters and optimize the network performance by proper dimensioning of the buffers.
The Internet Engineering Task Force (IETF) has proposed the Guaranteed Service (GS) in the Integrated Services model with firm delay and bandwidth guarantees. In this paper, we study the effects of a token bucket traffic shaper at the... more
The Internet Engineering Task Force (IETF) has proposed the Guaranteed Service (GS) in the Integrated Services model with firm delay and bandwidth guarantees. In this paper, we study the effects of a token bucket traffic shaper at the source on the transmission characteristics of Motion Picture Experts Group (MPEG) compressed video streams over the GS.
Abstract This paper demonstrates a successful application of wavelength division multiplexing (WDM) to the avionics environment to support analog RF signal transmission. We investigate the simultaneous transmission of four RF signals... more
Abstract This paper demonstrates a successful application of wavelength division multiplexing (WDM) to the avionics environment to support analog RF signal transmission. We investigate the simultaneous transmission of four RF signals (channels) over a single optical fiber. These four analog channels are sequentially multiplexed and demultiplexed at different points along a fiber optic backbone to more closely emulate the conditions found onboard aircraft.
Abstract The Hough transform is a robust method for detecting discontinuous patterns in noisy images. When it is applied to the detection of a straight line, represented by the normal parameters, the transform provides only the length of... more
Abstract The Hough transform is a robust method for detecting discontinuous patterns in noisy images. When it is applied to the detection of a straight line, represented by the normal parameters, the transform provides only the length of the normal and the angle it makes with the axis. The transform gives no information about the length or the end points of the line. A few authors have suggested algorithms or the determination of the length and the end points of a line.
Abstract IETF proposed network mobility (NEMO) basic support protocol (BSP) to support network mobility. NEMO BSP is an extension of Mobile IP v6 (MIPv6), and inherits all the drawbacks of MIPv6 (like inefficient routing, high handover... more
Abstract IETF proposed network mobility (NEMO) basic support protocol (BSP) to support network mobility. NEMO BSP is an extension of Mobile IP v6 (MIPv6), and inherits all the drawbacks of MIPv6 (like inefficient routing, high handover latency and packet loss rate). Satellites equipped with several IP-enabled devices are an example of network mobility in space networks.
Abstract Recent demand for real time applications has given rise to a need for quality of service (QoS) in the Internet. Differentiated Services is one such effort currently pursued by IETF. Previous researchers found unfairness in the... more
Abstract Recent demand for real time applications has given rise to a need for quality of service (QoS) in the Internet. Differentiated Services is one such effort currently pursued by IETF. Previous researchers found unfairness in the DiffServ network. To solve the unfairness problem, we propose a new TSW based three color marker (ItswTCM) which achieves proportional fair sharing of excess bandwidth among aggregates. We have compared the fairness of our proposed ItswTCM marker with srTCM, trTCM, and tswTCM.
Optical fiber offers many advantages over coaxial cable for the transmission of radio frequency (rf) signals in antenna-remoting applications, as well as cellular networks and cable television (CATV) signal distribution networks. Optical... more
Optical fiber offers many advantages over coaxial cable for the transmission of radio frequency (rf) signals in antenna-remoting applications, as well as cellular networks and cable television (CATV) signal distribution networks. Optical fiber shows significantly less loss, can support signals demanding much higher bandwidth, is immune to electromagnetic interference (EMI), and enables considerable size and weight savings when compared to coaxial cable.
16. ABSTRACT Roadway Weather Information System and Automatic Vehicle Location Coordination involves the development of an Inclement Weather Console that provides a new capability for the state of Oklahoma to monitor weather-related... more
16. ABSTRACT Roadway Weather Information System and Automatic Vehicle Location Coordination involves the development of an Inclement Weather Console that provides a new capability for the state of Oklahoma to monitor weather-related roadway conditions. The goal of this development is that motorist safety might be improved and the damage to highways and bridges caused by the application of deicing agents minimized through the use of the IWC and Decision Support Systems built upon it.
Abstract Scalable video transmission is used to adjust the rate of video depending on the level of network congestion. Previous studies on scalable video transmission of MPEG over ATM ABR service required major changes in the network... more
Abstract Scalable video transmission is used to adjust the rate of video depending on the level of network congestion. Previous studies on scalable video transmission of MPEG over ATM ABR service required major changes in the network protocols and did not provide methods to determine the ABR connection parameters. We propose a new scalable video transmission scheme which does not require major changes in network protocols.
Multistage switches consisting of a number of stages of small switching elements (SE) are often used in ATM switch fabrics. An ATM switch fabric performs the functions of switching and buffering of cells. The location of buffers inside a... more
Multistage switches consisting of a number of stages of small switching elements (SE) are often used in ATM switch fabrics. An ATM switch fabric performs the functions of switching and buffering of cells. The location of buffers inside a fabric is critical in the performance of the switch. Output buffered SEs have a higher throughput than input buffered SEs. Moreover, output buffered SEs do not suffer from buffer hogging as found in shared buffered SEs operating in a nonuniform traffic environment.
Abstract The objective of the authors is to develop an analytical model to evaluate the throughput and packet delay, in the presence of nonuniform traffic, in a MIN having multiple buffers at the output of the switching elements. The... more
Abstract The objective of the authors is to develop an analytical model to evaluate the throughput and packet delay, in the presence of nonuniform traffic, in a MIN having multiple buffers at the output of the switching elements. The model is based on Markov chains, and uses several simplifying assumptions to make the model tractable. The validity of the model has been verified by comparison of the results with those obtained from simulations