2018 IEEE Global Communications Conference (GLOBECOM), 2018
The use of satellite communications to support the Internet of Things paradigm is of paramount im... more The use of satellite communications to support the Internet of Things paradigm is of paramount importance for application scenarios where machines are spread in remote and wide areas. In such context, this paper proposes an efficient hierarchical radio access scheme. Ground machines randomly access the radio channel to communicate with their cluster heads, which in turn relay the cluster's aggregated traffic toward the satellite. The aim is optimizing the resource allocation to different communication stages, allowing resource reuse among clusters, in order to minimize the packet drop probability, and hence, to maximize the system throughput. First, the optimal solution is derived for the single cluster, then it is extended to the multi-cluster scenario. Numerical results show the effectiveness of the proposed method, also in comparison with benchmark approaches.
The ultra dense deployment of small cells is considered a key technology to achieve the requested... more The ultra dense deployment of small cells is considered a key technology to achieve the requested capacity in future cellular networks. However, the interference pattern becomes more unpredictable and challenging in these networks. Therefore, a suitable trade-off between spectrum spatial reuse and interference level has to be pursued to achieve good performance in terms of provided throughput. This paper proposes a new method to maximize the achievable throughput of an UDN with a suitable level of spatial spectrum reuse. In particular, the focus is on the small cells tier where the available spectrum is divided into sub-bands and each cell can use some of these to communicate with its associated users. The goal is to find the sub-bands allocation among cells that maximizes the system throughput. However, to limit complexity and signaling overhead that could result unaffordable in an UDN, a new metric to approximate the cell throughput to be optimized is defined. Moreover, the newly defined problem is solved using the Gibbs Sampling approach. The method effectiveness is proven by comparing the achieved results with those of the maximization of the effective system throughput and the optimal solution.
Ultra-Dense Network (UDN) deployment is considered a key element to achieve the requested capacit... more Ultra-Dense Network (UDN) deployment is considered a key element to achieve the requested capacity in future fifth-generation (5G) mobile networks. Backhaul networks in UDNs are formed by heterogeneous links with multi-hop connections and must handle massive traffic. Backhauling in future 5G networks may represent the capacity bottleneck. Therefore, there is the need for efficient and flexible routing schemes able to handle the dynamism of the traffic load in capacity-limited networks. Toward this goal, the emerging Software-Defined Network (SDN) paradigm provides an efficient solution, transferring the routing operation from the data plane switches to a central controller, thus achieving more flexibility, efficiency, and faster convergence time in comparison to conventional networks. This paper proposes and investigates an SDN-approach for an efficient routing in a capacity-limited backhaul network that carries data and control traffic of a heterogeneous UDN. The routing algorithm ...
Abstract: Nowadays people are used to going online to use a number of data sources, which provide... more Abstract: Nowadays people are used to going online to use a number of data sources, which provide information useful for their daily routine (status of transportation services, delay on commuters’ routes, traffic, weather etc.), as well as for leisure and social activities. At the same time, the availability of broadband connections allows mobile users to themselves become creators of online content, following the paradigm of Web 2.0. A large part of population is using social networks in their private life for sharing their daily experience through text or multimedia contents over several platforms with friends or even publically. Therefore, social networks represent a unique opportunity for bi-directional information exchange between a population and the authorities, acquiring a key role in emergency management. It is in fact possible to take advantage from a new “social awareness” of people that become in this way directly involved in crisis management by means of tools usually dedicate to recreational purposes. Official portals and institutional pages on social networks can be an efficient way to disseminate emergency alerts or information to large number of people. A quick advice dissemination is one of the most important things for reducing risks in disaster scenarios, and in many cases news is shared online by users before it is published on official portals; in particular the use of mobile devices increases the speed of information diffusion. Moreover, location-based applications can use information provided by official channels to show advice to citizens located in a particular emergency area and to assist them during rescue activities. This chapter describes how the collection of information posted on social media can make the difference in all emergency phases, and analyzes the available means which give citizens and authorities the possibility to accomplish their needs in emergency forecast, facing, management and response.
GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)
In this paper, the performance of a multiuser detection (MUD) receiver is investigated for a mult... more In this paper, the performance of a multiuser detection (MUD) receiver is investigated for a multi-carrier-code division multiple access (MC-CDMA) system in an indoor environment. Furthermore, low complexity pilot-aided methods are introduced for estimating channel parameters in an effort to study the resistance of the proposed solution to imperfect channel estimates. Simulation results show that benefits of MC-CDMA schemes, in
Handbook of Research on Software-Defined and Cognitive Radio Technologies for Dynamic Spectrum Management
Machine to Machine (M2M) communications have been recently introduced as a viable paradigm for al... more Machine to Machine (M2M) communications have been recently introduced as a viable paradigm for allowing low cost and efficient communications among devices mainly in an autonomous manner. Even if M2M protocols need dedicated resources, a new paradigm, called Cognitive M2M (CM2M) communications, has been recently considered exploiting cognitive/opportunistic radio communications. After having introduced the problem of applying cognitive techniques in M2M scenarios, the authors focus their attention on the Medium Access Control (MAC) protocols for CM2M scenarios, with a particular attention on the OFDMA-based primary systems. Among other approaches, the authors focus on a data-aided approach for the access of the secondary devices aiming to reduce interference toward the primary system.
International Journal of Antennas and Propagation, 2015
Among the mobile ad hoc networks appealing characteristics there are network reconfigurability an... more Among the mobile ad hoc networks appealing characteristics there are network reconfigurability and flexibility. In this context a smart antenna capable of self-configuring multiple high-directivity beams provides a major advantage in terms of power saving, increased range, and spatial reuse of channels. In this paper a smart antenna made of a cylindrical array of patches suitable for MANETs is presented.
Proceedings of the 2009 International Conference on Wireless Communications and Mobile Computing: Connecting the World Wirelessly, 2009
ABSTRACT Wireless communications have achieved a great attention during the last decades due to t... more ABSTRACT Wireless communications have achieved a great attention during the last decades due to the easy implementation, pos-sibility of delivering multimedia services to rural communi-ties, suitability for public safety and emergency communi-cations. In particular, ...
Heterogeneous network deployment represents one of the main enhancements of future LTE-A networks... more Heterogeneous network deployment represents one of the main enhancements of future LTE-A networks to increase spectrum efficiency. However, the achievable improvements are limited by the interference that arises from a co-channel allocation of the cells. This paper proposes two cognitive resource allocation methods that work using the angle of arrival of the signals instead of the channel state information. Both methods reduce the interference towards the macro-cell User Equipments (MUEs) using Zero Forcing Beamforming to avoid transmission in the MUEs direction. At the same time they maximize the capacity of the femto-cell with a suitable allocation of the time-frequency resources to the femto-cell UEs (FUEs). The performance of the proposed methods is compared with that of a conventional maximum gain beamforming and conventional zero forcing beamforming. The results show that the proposed methods achieve a good trade off between maximization of the femto-cell capacity and reduction of the interference level at the MUEs side.
ABSTRACT This paper deals with a cognitive approach used to reduce the co-channel interference ar... more ABSTRACT This paper deals with a cognitive approach used to reduce the co-channel interference arising from the coexistence of an LTE macrocell and an LTE femtocell sharing the same frequency band. Multiple-antennas technology is considered to exploit the angle dimension as a new spectrum opportunity: femtocell acts as a secondary system and inserts nulls in the directions of the UE connected to the macrocell thus protecting the downlink transmission of the primary base station. MuSiC algorithm is used to detect the DOA of the UE signal replicas in an indoor environment assuming a variable number of multipath components characterized by a very large angle spread. The proposed scheme permits to increase the signal to interference ratio at the UE side thus reducing the achieved error rate on the downlink connection even when the number of resolvable paths is higher than the number of antennas. Finally the UE mobility is considered to take into account the effect of variable DOAs.
2008 IEEE International Conference on Communications, 2008
AbstractWiMAX is one of the most important technologies for providing a Broadband Wireless Acces... more AbstractWiMAX is one of the most important technologies for providing a Broadband Wireless Access (BWA) in a metropoli-tan area. The use of OFDM transmission has been proposed to reduce the effect of multipath fading in wireless communications; moreover, multiple ...
Network coding (NC) is a promising technique recently proposed to improve network performance in ... more Network coding (NC) is a promising technique recently proposed to improve network performance in terms of maximum throughput, minimum delivery delay, and energy consumption. The original proposal highlighted the advantages of NC for multicast communications in wire-line networks. Recently, network coding has been considered as an efficient approach to improve performance in wireless networks, mainly in terms of data reliability and lower energy consumption, especially for broadcast communications. The basic idea of NC is to remove the typical requirement that different information flows have to be processed and transmitted independently through the network. When NC is applied, intermediate nodes in the network do not simply relay the received packets, but they combine several received packets before transmission. As a consequence, the output flow at a given node is obtained as a linear combination of its input flows. This chapter deals with the application of network coding principl...
This paper deals with the problem of finding an optimal subcarrier allocation strategy for uplink... more This paper deals with the problem of finding an optimal subcarrier allocation strategy for uplink and downlink communications in an OFDMA metropolitan wireless system. Three different resource allocation algorithms are proposed by taking into account the Quality of Service (QoS) constraints and the user’s channel conditions. Moreover, a simple strategy for choosing the most appropriate Modulation and Coding Scheme (MCS)
2018 IEEE Global Communications Conference (GLOBECOM), 2018
The use of satellite communications to support the Internet of Things paradigm is of paramount im... more The use of satellite communications to support the Internet of Things paradigm is of paramount importance for application scenarios where machines are spread in remote and wide areas. In such context, this paper proposes an efficient hierarchical radio access scheme. Ground machines randomly access the radio channel to communicate with their cluster heads, which in turn relay the cluster's aggregated traffic toward the satellite. The aim is optimizing the resource allocation to different communication stages, allowing resource reuse among clusters, in order to minimize the packet drop probability, and hence, to maximize the system throughput. First, the optimal solution is derived for the single cluster, then it is extended to the multi-cluster scenario. Numerical results show the effectiveness of the proposed method, also in comparison with benchmark approaches.
The ultra dense deployment of small cells is considered a key technology to achieve the requested... more The ultra dense deployment of small cells is considered a key technology to achieve the requested capacity in future cellular networks. However, the interference pattern becomes more unpredictable and challenging in these networks. Therefore, a suitable trade-off between spectrum spatial reuse and interference level has to be pursued to achieve good performance in terms of provided throughput. This paper proposes a new method to maximize the achievable throughput of an UDN with a suitable level of spatial spectrum reuse. In particular, the focus is on the small cells tier where the available spectrum is divided into sub-bands and each cell can use some of these to communicate with its associated users. The goal is to find the sub-bands allocation among cells that maximizes the system throughput. However, to limit complexity and signaling overhead that could result unaffordable in an UDN, a new metric to approximate the cell throughput to be optimized is defined. Moreover, the newly defined problem is solved using the Gibbs Sampling approach. The method effectiveness is proven by comparing the achieved results with those of the maximization of the effective system throughput and the optimal solution.
Ultra-Dense Network (UDN) deployment is considered a key element to achieve the requested capacit... more Ultra-Dense Network (UDN) deployment is considered a key element to achieve the requested capacity in future fifth-generation (5G) mobile networks. Backhaul networks in UDNs are formed by heterogeneous links with multi-hop connections and must handle massive traffic. Backhauling in future 5G networks may represent the capacity bottleneck. Therefore, there is the need for efficient and flexible routing schemes able to handle the dynamism of the traffic load in capacity-limited networks. Toward this goal, the emerging Software-Defined Network (SDN) paradigm provides an efficient solution, transferring the routing operation from the data plane switches to a central controller, thus achieving more flexibility, efficiency, and faster convergence time in comparison to conventional networks. This paper proposes and investigates an SDN-approach for an efficient routing in a capacity-limited backhaul network that carries data and control traffic of a heterogeneous UDN. The routing algorithm ...
Abstract: Nowadays people are used to going online to use a number of data sources, which provide... more Abstract: Nowadays people are used to going online to use a number of data sources, which provide information useful for their daily routine (status of transportation services, delay on commuters’ routes, traffic, weather etc.), as well as for leisure and social activities. At the same time, the availability of broadband connections allows mobile users to themselves become creators of online content, following the paradigm of Web 2.0. A large part of population is using social networks in their private life for sharing their daily experience through text or multimedia contents over several platforms with friends or even publically. Therefore, social networks represent a unique opportunity for bi-directional information exchange between a population and the authorities, acquiring a key role in emergency management. It is in fact possible to take advantage from a new “social awareness” of people that become in this way directly involved in crisis management by means of tools usually dedicate to recreational purposes. Official portals and institutional pages on social networks can be an efficient way to disseminate emergency alerts or information to large number of people. A quick advice dissemination is one of the most important things for reducing risks in disaster scenarios, and in many cases news is shared online by users before it is published on official portals; in particular the use of mobile devices increases the speed of information diffusion. Moreover, location-based applications can use information provided by official channels to show advice to citizens located in a particular emergency area and to assist them during rescue activities. This chapter describes how the collection of information posted on social media can make the difference in all emergency phases, and analyzes the available means which give citizens and authorities the possibility to accomplish their needs in emergency forecast, facing, management and response.
GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489)
In this paper, the performance of a multiuser detection (MUD) receiver is investigated for a mult... more In this paper, the performance of a multiuser detection (MUD) receiver is investigated for a multi-carrier-code division multiple access (MC-CDMA) system in an indoor environment. Furthermore, low complexity pilot-aided methods are introduced for estimating channel parameters in an effort to study the resistance of the proposed solution to imperfect channel estimates. Simulation results show that benefits of MC-CDMA schemes, in
Handbook of Research on Software-Defined and Cognitive Radio Technologies for Dynamic Spectrum Management
Machine to Machine (M2M) communications have been recently introduced as a viable paradigm for al... more Machine to Machine (M2M) communications have been recently introduced as a viable paradigm for allowing low cost and efficient communications among devices mainly in an autonomous manner. Even if M2M protocols need dedicated resources, a new paradigm, called Cognitive M2M (CM2M) communications, has been recently considered exploiting cognitive/opportunistic radio communications. After having introduced the problem of applying cognitive techniques in M2M scenarios, the authors focus their attention on the Medium Access Control (MAC) protocols for CM2M scenarios, with a particular attention on the OFDMA-based primary systems. Among other approaches, the authors focus on a data-aided approach for the access of the secondary devices aiming to reduce interference toward the primary system.
International Journal of Antennas and Propagation, 2015
Among the mobile ad hoc networks appealing characteristics there are network reconfigurability an... more Among the mobile ad hoc networks appealing characteristics there are network reconfigurability and flexibility. In this context a smart antenna capable of self-configuring multiple high-directivity beams provides a major advantage in terms of power saving, increased range, and spatial reuse of channels. In this paper a smart antenna made of a cylindrical array of patches suitable for MANETs is presented.
Proceedings of the 2009 International Conference on Wireless Communications and Mobile Computing: Connecting the World Wirelessly, 2009
ABSTRACT Wireless communications have achieved a great attention during the last decades due to t... more ABSTRACT Wireless communications have achieved a great attention during the last decades due to the easy implementation, pos-sibility of delivering multimedia services to rural communi-ties, suitability for public safety and emergency communi-cations. In particular, ...
Heterogeneous network deployment represents one of the main enhancements of future LTE-A networks... more Heterogeneous network deployment represents one of the main enhancements of future LTE-A networks to increase spectrum efficiency. However, the achievable improvements are limited by the interference that arises from a co-channel allocation of the cells. This paper proposes two cognitive resource allocation methods that work using the angle of arrival of the signals instead of the channel state information. Both methods reduce the interference towards the macro-cell User Equipments (MUEs) using Zero Forcing Beamforming to avoid transmission in the MUEs direction. At the same time they maximize the capacity of the femto-cell with a suitable allocation of the time-frequency resources to the femto-cell UEs (FUEs). The performance of the proposed methods is compared with that of a conventional maximum gain beamforming and conventional zero forcing beamforming. The results show that the proposed methods achieve a good trade off between maximization of the femto-cell capacity and reduction of the interference level at the MUEs side.
ABSTRACT This paper deals with a cognitive approach used to reduce the co-channel interference ar... more ABSTRACT This paper deals with a cognitive approach used to reduce the co-channel interference arising from the coexistence of an LTE macrocell and an LTE femtocell sharing the same frequency band. Multiple-antennas technology is considered to exploit the angle dimension as a new spectrum opportunity: femtocell acts as a secondary system and inserts nulls in the directions of the UE connected to the macrocell thus protecting the downlink transmission of the primary base station. MuSiC algorithm is used to detect the DOA of the UE signal replicas in an indoor environment assuming a variable number of multipath components characterized by a very large angle spread. The proposed scheme permits to increase the signal to interference ratio at the UE side thus reducing the achieved error rate on the downlink connection even when the number of resolvable paths is higher than the number of antennas. Finally the UE mobility is considered to take into account the effect of variable DOAs.
2008 IEEE International Conference on Communications, 2008
AbstractWiMAX is one of the most important technologies for providing a Broadband Wireless Acces... more AbstractWiMAX is one of the most important technologies for providing a Broadband Wireless Access (BWA) in a metropoli-tan area. The use of OFDM transmission has been proposed to reduce the effect of multipath fading in wireless communications; moreover, multiple ...
Network coding (NC) is a promising technique recently proposed to improve network performance in ... more Network coding (NC) is a promising technique recently proposed to improve network performance in terms of maximum throughput, minimum delivery delay, and energy consumption. The original proposal highlighted the advantages of NC for multicast communications in wire-line networks. Recently, network coding has been considered as an efficient approach to improve performance in wireless networks, mainly in terms of data reliability and lower energy consumption, especially for broadcast communications. The basic idea of NC is to remove the typical requirement that different information flows have to be processed and transmitted independently through the network. When NC is applied, intermediate nodes in the network do not simply relay the received packets, but they combine several received packets before transmission. As a consequence, the output flow at a given node is obtained as a linear combination of its input flows. This chapter deals with the application of network coding principl...
This paper deals with the problem of finding an optimal subcarrier allocation strategy for uplink... more This paper deals with the problem of finding an optimal subcarrier allocation strategy for uplink and downlink communications in an OFDMA metropolitan wireless system. Three different resource allocation algorithms are proposed by taking into account the Quality of Service (QoS) constraints and the user’s channel conditions. Moreover, a simple strategy for choosing the most appropriate Modulation and Coding Scheme (MCS)
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Papers by Dania Marabissi