Halima Elbiaze
Université du Québec à Montréal, Informatique, Faculty Member
- Halima Elbiaze holds a Ph.D. in computer science and a M.Sc in Telecommunication systems from Institut National des T... moreHalima Elbiaze holds a Ph.D. in computer science and a M.Sc in Telecommunication systems from Institut National des Télécommunications, Paris, France and Université de Versailles in 2002 and 1998. Since 2003, she is with the Department of Computer Science, Université du Québec Montréal, QC, Canada, where she is currently an Associate Professor. In 2005, Dr. Elbiaze received the Canada Foundation for Innovation Award to build her IP over the DWDM network Laboratory. Her research interests include performance evaluation, traffic engineering, cloud computing, wireless networks, and next generation IP networks. She had been awarded many research grants from both public agencies and industry.edit
In OBS networks, contention caused by multiple bursts competing simultaneously for a given wavelength on a fiber link, significantly increases the burst dropping probability and hence deteriorates the overall network performance. Several... more
In OBS networks, contention caused by multiple bursts competing simultaneously for a given wavelength on a fiber link, significantly increases the burst dropping probability and hence deteriorates the overall network performance. Several studies tackled the contention resolution in OBS networks; however several issues still need to be addressed such as quality of service (QoS) guarantee, protection and restoration. The separation
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ABSTRACT The main weakness of OBS (Optical Burst Switching) networks is the difficulty to support different types of traffic requiring several performance constraints. This paper focuses on the design and the performance evaluation of... more
ABSTRACT The main weakness of OBS (Optical Burst Switching) networks is the difficulty to support different types of traffic requiring several performance constraints. This paper focuses on the design and the performance evaluation of efficient cognitive OBS protocols that pave a way to the multi-service context. We present a graphical probabilistic model to avoid and resolve contention inside the OBS network. In order to efficiently exploit the available bandwidth while respecting QoS requirements, we highlight our complete framework using closed/open loop feedback control theoretic techniques to improve OBS networks performance.
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ABSTRACT A key goal of designing memoryless OBS networks is the minimization of burst loss. Loss is due mainly to restraints that can occur at core nodes, such as contention. Such events occurring at OBS layer are misinterpreted by TCP... more
ABSTRACT A key goal of designing memoryless OBS networks is the minimization of burst loss. Loss is due mainly to restraints that can occur at core nodes, such as contention. Such events occurring at OBS layer are misinterpreted by TCP congestion control mechanisms that reacts on (i) burst drops, (ii) end-to-end delay variation and (iii) throughput changes. This paper proposes a destination-ordering mechanism over a load balanced OBS network, that minimizes TCP misinterpretation and maximizes TCP throughput.
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ABSTRACT Femtocell and WiFi are often presented as opposing technologies. The truth is that both of them play a crucial role in sustaining the continues growth in mobile traffic. In many cases both technologies will eventually be employed... more
ABSTRACT Femtocell and WiFi are often presented as opposing technologies. The truth is that both of them play a crucial role in sustaining the continues growth in mobile traffic. In many cases both technologies will eventually be employed in a single box with access via an intelligent mobile device that will automatically select the best option. Deploying Femtocells in WiFi hotspots would let access providers add 3G capacity for users who do not have WiFi on their device and improve their quality of experience during mobility. Partitioning of the spectrum resources carries critical importance for maximizing the total capacity and quality of service (QoS) satisfaction of end users. This paper proposes a fair and QoS-based unlicensed spectrum splitting strategy between WiFi and Femtocell networks. Numerical results show that spectrum splitting under total capacity maximization constraint allows for unfair spectrum allocation, while a more equitable spectrum splitting can be accomplished by taking into account the fairness and QoS constraints.
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... 2003. [9] VM Vokkarane, K. Haridoss, and JP Jue, Threshold-based burst assembly policies for QoS support in optical burst-switched networks, Proc. of SPIE OptiComm, July 2002. ... of IEEE Globecom, San Francisco, CA, USA, Nov. 2003.... more
... 2003. [9] VM Vokkarane, K. Haridoss, and JP Jue, Threshold-based burst assembly policies for QoS support in optical burst-switched networks, Proc. of SPIE OptiComm, July 2002. ... of IEEE Globecom, San Francisco, CA, USA, Nov. 2003. [18] Qiong Zhang, Vinod M. Vokkarane ...
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This paper presents a new structure-preserving method of sampling self-similar traffic with direct applications to network monitoring and resource provisioning. Predicting the bandwidth required by upcoming traffic plays a key role for... more
This paper presents a new structure-preserving method of sampling self-similar traffic with direct applications to network monitoring and resource provisioning. Predicting the bandwidth required by upcoming traffic plays a key role for providing an efficient and intelligent resource provisioning, especially in the context of IP over WDM. To achieve this, we are proposing a periodic sampling method (called maximum-based sampling)
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This paper focuses on the design and analysis of QoS-based scheduling mechanism for service differentiation in Optical Flow Switching (OFS) networks. We consider two types of traffic flows: (i) delay-constraint flows (high priority flows)... more
This paper focuses on the design and analysis of QoS-based scheduling mechanism for service differentiation in Optical Flow Switching (OFS) networks. We consider two types of traffic flows: (i) delay-constraint flows (high priority flows) and (ii) Best-effort flows (low priority flows). In OFS, only optical cross connects (OXCs) are used for the switching function in the data plane and there
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Cognitive radio networks are composed of spectrum-agile devices capable of changing their configurations and transmission parameters on the fly based on their spectral environment. This capability opens up the possibility of designing... more
Cognitive radio networks are composed of spectrum-agile devices capable of changing their configurations and transmission parameters on the fly based on their spectral environment. This capability opens up the possibility of designing flexible and dynamic spectrum access strategies with the purpose of opportunistically reusing portions of the spectrum temporarily vacated by licensed primary users. However, this flexibility in the spectrum
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Spectrum sharing between license holders (primary users) and unlicensed secondary users has been proposed as a solution to frequency wastage. Anyhow, the coexistence among these two types of users should not affect the quality of service... more
Spectrum sharing between license holders (primary users) and unlicensed secondary users has been proposed as a solution to frequency wastage. Anyhow, the coexistence among these two types of users should not affect the quality of service of primary users. In this paper, we propose an interference control approach when one primary and multiple secondary users are simultaneously transmitting on the
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This article focuses on the control plan of IP over WDM networks. Analytical and measurement studies have shown that self-similar traffic can have detrimental impact on network performance in terms of queuing delay and packet loss ratio.... more
This article focuses on the control plan of IP over WDM networks. Analytical and measurement studies have shown that self-similar traffic can have detrimental impact on network performance in terms of queuing delay and packet loss ratio. Nevertheless, the ubiquity of scale-invariant burstiness observed across diverse network contexts can be exploited to make more efficient resource-control decisions. This paper shows
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The focus of this paper is the shaping of self-similar traffic at the access of an optical node. We propose a novel algorithm that dynamically shapes the incoming traffic, based on service curves equations, in order to meet the optical... more
The focus of this paper is the shaping of self-similar traffic at the access of an optical node. We propose a novel algorithm that dynamically shapes the incoming traffic, based on service curves equations, in order to meet the optical nodes constraints in terms of buffer size or delay. We first estimate arrival parameters within various time intervals in order
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Traffic prediction constitutes a new hot research topic of network metrology. Thus, tuning the prediction model parameters is very crucial to achieve accurate prediction. This work focuses on the design, the empirical evaluation and the... more
Traffic prediction constitutes a new hot research topic of network metrology. Thus, tuning the prediction model parameters is very crucial to achieve accurate prediction. This work focuses on the design, the empirical evaluation and the analysis of the behavior of training-based models for predicting the throughput of a single link i.e. the incoming input data in Megabit per time interval
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This paper proposes a new UCLP (User-Controlled LightPath) architecture that offers end-to-end optical services provisioning in a multi-domain network. It also shows the experimental results of our UCLP software tool implemented on the... more
This paper proposes a new UCLP (User-Controlled LightPath) architecture that offers end-to-end optical services provisioning in a multi-domain network. It also shows the experimental results of our UCLP software tool implemented on the Canarie optical network testbed. This work is motivated by the growing need for end-to-end lightpaths to support high volume data transferring applications such as GridFTP (GRID File
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Active Queue Management (AQM) policies are mechanisms for congestion avoidance, which pro-actively drop packets in order to provide an early congestion notification to the sources. Random Early Detection (RED), the defacto standard and... more
Active Queue Management (AQM) policies are mechanisms for congestion avoidance, which pro-actively drop packets in order to provide an early congestion notification to the sources. Random Early Detection (RED), the defacto standard and its different flavors have been proposed as simple solutions to the AQM problem. However, these approaches require manual tuning and fail to accurately capture variations in the
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The gool of this paper is the traffic management in the multiservice optical network context (ROM). We suggest centralising the traf- fic management policies at the interface between the client layers and the ROM network. The key idea is... more
The gool of this paper is the traffic management in the multiservice optical network context (ROM). We suggest centralising the traf- fic management policies at the interface between the client layers and the ROM network. The key idea is then to exploit, in an optimal way, the electronic memories in the electronic interfaces at the edge nodes of the optical
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Optical burst switching (OBS) is a new optical switching paradigm where traffic can be switched and groomed at a lower level compared to optical switched circuit (OCS). While OCS is useful in carrying highly aggregated long-lived streams... more
Optical burst switching (OBS) is a new optical switching paradigm where traffic can be switched and groomed at a lower level compared to optical switched circuit (OCS). While OCS is useful in carrying highly aggregated long-lived streams that require absolute quality of service (QoS) guarantees, OBS has a role in efficiently carrying bursty best-effort traffic. In this paper, we investigate
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Optical burst switching (OBS) is a new optical switching paradigm where traffic can be switched and groomed at a lower level compared to optical circuit switching (OCS). Although research in OBS networks has evolved from theoretical... more
Optical burst switching (OBS) is a new optical switching paradigm where traffic can be switched and groomed at a lower level compared to optical circuit switching (OCS). Although research in OBS networks has evolved from theoretical investigations to proof-of-concept demonstrations, several key issues need to be investigated further before OBS prototypes can clearly outperformed OCS networks. While the burst loss
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ABSTRACT Optical Burst Switching (OBS) is a new optical switching paradigm where traffic can be switched and groomed at a lower level compared to Optical Switched Circuit (OCS). While OCS is useful in carrying highly aggregated long-lived... more
ABSTRACT Optical Burst Switching (OBS) is a new optical switching paradigm where traffic can be switched and groomed at a lower level compared to Optical Switched Circuit (OCS). While OCS is useful in carrying highly aggregated long-lived streams that require absolute ...
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Optical burst switching (OBS) is a new optical switching paradigm where traffic can be switched and groomed at a lower level compared to optical circuit switching (OCS). Although research in OBS networks has evolved from theoretical... more
Optical burst switching (OBS) is a new optical switching paradigm where traffic can be switched and groomed at a lower level compared to optical circuit switching (OCS). Although research in OBS networks has evolved from theoretical investigations to proof-of-concept demonstrations, several key issues need to be investigated further before OBS prototypes can clearly outperformed OCS networks. While the burst loss
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The gool of this paper is the traffic management in the multiservice optical network context (ROM). We suggest centralising the traf- fic management policies at the interface between the client layers and the ROM network. The key idea is... more
The gool of this paper is the traffic management in the multiservice optical network context (ROM). We suggest centralising the traf- fic management policies at the interface between the client layers and the ROM network. The key idea is then to exploit, in an optimal way, the electronic memories in the electronic interfaces at the edge nodes of the optical
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... Institut National des Télécommunications 9 rue Charles Fourier 91011 Evry CEDEX - France {halima.elbiaze, tijani.chahed, tulin.atmaca, gerard.hebuterne ... We propose a novel algorithm that dy-namically shapes the incoming traffic,... more
... Institut National des Télécommunications 9 rue Charles Fourier 91011 Evry CEDEX - France {halima.elbiaze, tijani.chahed, tulin.atmaca, gerard.hebuterne ... We propose a novel algorithm that dy-namically shapes the incoming traffic, based on service curves equations, in order ...
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ABSTRACT This paper presents a policy-based management framework for GMPLS-enabled optical networks. First, the (Automatic Switched Optical Networks) and GMPLS (Generalized Multi-Protocol Label Switching) architecture are presented. We... more
ABSTRACT This paper presents a policy-based management framework for GMPLS-enabled optical networks. First, the (Automatic Switched Optical Networks) and GMPLS (Generalized Multi-Protocol Label Switching) architecture are presented. We then present a framework based on an admission control protocol COPS (Common Open Policy Service) defined by the IETF (Internet Engineering Task Force) and on an Information Model based on the CIM (Common Information Model) model defined by DMTF (Distributed Management Task Force). This framework allows interworking between the policy and control plane, and provides a comprehensive policy provisioning setup for optical networks. An information model extended from CIM for managing dynamically configured optical networks is presented.
A NOVEL OFFSET-BASED RESTORATION MECHANISM FOR OPTICAL BURST SWITCHED NETWORKS Salim Y. Said , Hussein T. Mouftah , and Halima Elbiaze School of Information Technology and Engineering (SITE), University of Ottawa, 800 King Edward Ave... more
A NOVEL OFFSET-BASED RESTORATION MECHANISM FOR OPTICAL BURST SWITCHED NETWORKS Salim Y. Said , Hussein T. Mouftah , and Halima Elbiaze School of Information Technology and Engineering (SITE), University of Ottawa, 800 King Edward Ave ...
ABSTRACT QoS support and network survivability are crucial issues in optical burst switched (OBS) networks to form a smooth transition toward next generation optical Internet. This paper presents a QoS-based restoration mechanism for OBS... more
ABSTRACT QoS support and network survivability are crucial issues in optical burst switched (OBS) networks to form a smooth transition toward next generation optical Internet. This paper presents a QoS-based restoration mechanism for OBS networks based on offset time ...
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Optical burst switching (OBS) is a very promising technology for the next generation of optical Internet. In OBS networks, contention caused by multiple bursts competing simultaneously for a given wavelength on a fiber link, significantly... more
Optical burst switching (OBS) is a very promising technology for the next generation of optical Internet. In OBS networks, contention caused by multiple bursts competing simultaneously for a given wavelength on a fiber link, significantly increases the burst dropping probability and hence deteriorates the overall network performance. That is the reason why finding solutions in order to minimize burst dropping
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Research Interests: Optical Fiber Communications, Routing algorithm, Bayesian Networks, Bayesian statistics & modelling, Artificial Intelligent, and 9 moreInternet Architecture, Optical Burst Switching, Bayesian Network, Wavelength Conversion, Traffic Matrix, Network Topology, Dynamic Loading, Shortest Path, and Network Simulator
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Burst dropping rate is a major issue for OBS networks. Unlike classical circuit switching, contention between bursts may cause blocking and make consequent loss within the network. Since the network can not carry a burst without its... more
Burst dropping rate is a major issue for OBS networks. Unlike classical circuit switching, contention between bursts may cause blocking and make consequent loss within the network. Since the network can not carry a burst without its control packet, the control channel must be able to carry the complete BCP load. We propose a new assembly mechanism which takes into account the control channel availability. In this mechanism, a burst is created only if its control packet can be transmitted. We present preliminary results that show how monitoring the control channel in the burst assembly mechanism can significantly improve the network performance. Simulations show that the proposed mechanism changes adaptively the burst length, reduces the possibility of continuous blocking problem, reduces the packets loss rate, and increases the throughput while still satisfying the maximum assembly delay.
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ABSTRACT This letter considers the problem of scheduling in the multiple input multiple output (MIMO) multiple-access wireless channel, where the transmitters are energy harvesting nodes (EHNs) that are powered by renewable energy sources... more
ABSTRACT This letter considers the problem of scheduling in the multiple input multiple output (MIMO) multiple-access wireless channel, where the transmitters are energy harvesting nodes (EHNs) that are powered by renewable energy sources (RESs). In this letter the conventional scheduling objective of maximizing rate is augmented by two other objectives, regulating fairness, and stabilization of the stored energy processes of the EHNs. This problem is formulated as a network of energy queues, which represent the batteries. Considering the stochastic nature of the wireless channel and the energy harvesting processes, this letter employs Lyapunov drift plus penalty technique to develop a cross-layer scheduler that operates in a slotted-time and distributed manner. At each epoch it selects an EHN for transmission and computes the transmit power. As an added advantage, the power control algorithm still retains the optimal water-filling solution. Through simulations, the proposed solution is compared against a conventional max-rate scheduler and is shown to better enforce fairness, stabilize the battery levels, and minimize the required battery capacity.
This paper focuses on the design and analysis of QoS-based scheduling mechanism for service differentiation in Optical Flow Switching (OFS) networks. We consider two types of traffic flows: (i) delay-constraint flows (high priority flows)... more
This paper focuses on the design and analysis of QoS-based scheduling mechanism for service differentiation in Optical Flow Switching (OFS) networks. We consider two types of traffic flows: (i) delay-constraint flows (high priority flows) and (ii) Best-effort flows (low priority flows). In OFS, only optical cross connects (OXCs) are used for the switching function in the data plane and there is no buffering and processing involved at intermediate routes. Data flows through a simple all-optical data plane without any electronic processing except for the control plane. The flow QoS-based scheduling mechanism is to be implemented in the control plane using a priority queueing. We develop an analytical model to evaluate the performance of the considered OFS network using the proposed scheduling mechanism. Simulations are also conducted in order to validate the obtained analytical results. Numerical results have shown the efficiency of the QoS-based scheduling mechanism in satisfying delay constraint for DC flows especially when the contention for resource becomes noticeable (i.e. high network load).
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ABSTRACT In this paper we consider the problem of user assignment and power allocation in a small cell environment which is one of the most important problems in present wireless cellular network research. We consider a two-tier cellular... more
ABSTRACT In this paper we consider the problem of user assignment and power allocation in a small cell environment which is one of the most important problems in present wireless cellular network research. We consider a two-tier cellular network where randomly dispersed overlay femtocell base stations (FBSs) coexist with a macrocell. Our objective is to maximize the total number of users served by the FBSs while satisfying their signal to noise and interference (SINR) requirements. This problem is known to be NP-Hard and hence there is no known optimal solution to solve it in polynomial time. First we formulate the problem of maximization of allocated users under SINR constraints with constant transmit power as an integer programming problem. We provide two heuristic polynomial time algorithms. Then we propose a third algorithm for joint power and user allocation. We evaluate the complexity of the proposed algorithms and furthermore compare the results against the brute force optimal solution and a basic random user assignment through simulations. The results demonstrate the performance and the efficiency of the proposed algorithms. We see in the simulation that the best proposed heuristic for maximizing the number of assigned users is only 3% less than the optimal while reducing the power consumption below that of the optimal user assignment algorithm.