Angelo Trotta | Università di Bologna (original) (raw)
Papers by Angelo Trotta
Computer Communications, 2015
Nowadays, spontaneous wireless networks enabled by mobile end-user devices (e.g. smartphones or t... more Nowadays, spontaneous wireless networks enabled by mobile end-user devices (e.g. smartphones or tablets) are receiving considerable interest due the possibility to offer a wide range of novel, highly pervasive and user-centric network services and applications. In this paper, we focus on emergency-related scenarios, and we investigate the potential of spontaneous networks for providing Internet connectivity over the emergency area through the sharing of resources owned by the end-user devices. Novel and extremely flexible network deployment strategies are required in order to cope with the user mobility, the limited communication capabilities of wireless devices, and the intrinsic dinamicity of traffic loads and QoS requirements. To this purpose, we propose here a novel approach toward the deployment of spontaneous networks composed by a new generation of wireless devices -called Stem Nodes (SNs) to emphasize their ability to cover multiple network roles (e.g. gateway, router). The self-organization of the spontaneous network is then achieved through the local reconfiguration of each SN. Two complementary research contributions are provided. First, we describe the software architecture of a SN (which can be implemented on top of existing end-user devices), and we detail how a SN can manage its role set, eventually extending it through cooperation with other SNs. Second, we propose distributed algorithms, based on swarm intelligence principles, through which each SN can autonously select its role, and self-elect to gateways or routers, so that end-to-end performance are maximized while the lifetime of the spontaneous emergency network is prolonged. The ability of the proposed algorithm to guarantee adaptive and self-organizing network behaviours is demostrated through extensive Omnet++ simulations, and through a prototype implementation of the SN architecture on a real testbed.
After the digital TV switch-over, national spectrum regulators are considering opportunistic sp... more After the digital TV switch-over, national spectrum regulators are considering opportunistic spectrum access techniques in the TV White Spaces (TVWS) frequency band. At present, the reference solution envisages the utilization of geolocation spectrum databases (GLDBs), in which spectrum availability is computed through complex propagation models. However, recent studies indicate that the used path loss model in GLDBs could be either inaccurate or too much conservative, possibly reducing the use of TVWS for opportunistic use by secondary networks. In this paper, we investigate the possibility to enhance the estimation accuracy of GLDBs with sensing reports produced by a swarm of Unmanned Aerial Scanning Vehicles (UASVs). These latter are able to explore the scenario in both space and frequencies, and to build a fine-grained shadowing map which can be used to tune the accuracy of propagation model used by GLDB. A novel distributed mobility algorithm is described for the sensing coverage of the scenario, and an aggregation mechanism for the map creation is illustrated. Simulation results confirm the effectiveness of our scheme in terms of TVWS detection accuracy and scenario coverage issues.
2013 9th International Wireless Communications and Mobile Computing Conference, IWCMC 2013, 2013
In this paper, we address the problem of reestablishing the network connectivity in post-disaster... more In this paper, we address the problem of reestablishing the network connectivity in post-disaster scenarios, where the original wireless infrastructure has been partitioned into multiple network fragments (called islands), operating on different frequencies. To this purpose, we propose the utilization of swarms of dedicated repairing units, called Stem-Nodes (SNs). SNs are provided with Cognitive Radio (CR) and self-positioning capabilities, in order to offer maximum reconfigurability in terms of mobility and wireless technologies supported. Moreover, swarms of SNs can self-organize into STEM-Mesh structure, that works as a dynamic backbone to connect heterogeneous islands using different technologies (e.g. Wi-Fi, Wi-MAX, etc). In this paper, we present three contributions pertaining to STEM-Mesh: (i) we describe a distributed motion control scheme (based on virtual springs approach) that enables SNs to self-organize into dynamic STEM-Mesh structures, (ii) we introduce a discovery scheme, through which SNs can explore the scenario in both spatial and frequency domains, and possibly connect the islands to the STEM-Mesh backbone and (iii) we validate the correctness of the proposed scheme, by verifying the optimal placements of the SNs composing the STEM-Mesh on a simplified scenario (e.g. chain topology). Finally, we evaluate through Omnet++ simulations the ability of STEM-Mesh to maximally re-establish connectivity on partitioned network scenarios.
Spontaneous networks among end-user devices (e.g. smartphones, tablets) can guarantee emergency c... more Spontaneous networks among end-user devices (e.g. smartphones, tablets) can guarantee emergency communication in post-disaster scenarios where the original infrastructure has been partially damaged by the occurrence of unpredictable or catastrophic events. However, the heterogeneity of devices and wireless access technologies poses important challenges on the network deployment and management. In this paper, we propose the STEM-Net architecture as a viable network model to handle the devices' heterogeneity and to enable spontaneous networking functionalities in post-disaster scenarios. In STEM-Net, the wireless devices -called Stem Nodes (SN)-are able to adapt their transmitting configurations, cover different roles (e.g. router, bridge, etc) according to the system needs and evolve their functionalities through cooperation with other nodes. Here, we provide a proof-of-concept of the principles of nodes' mutation and evolution, by discussing how heterogeneous end-user devices provided with SN capabilities can dynamically self-organize into multi-hop networks, and share the Internet access by switching among three roles: stub, transit and gateway SNs. A bio-inspired distributed gateway selection mode is proposed to allow each SN device to decide its current role, based on the system needs and on the individual hardware characteristics and resources (e.g. residual energy or queue occupation). The simulation analysis conducted with the Omnet++ tool demonstrates the effectiveness of the STEM-Net framework in prolonging the network lifetime while providing adequate bandwidth for emergency communication to the end-users devices.
Nell'ultimo decennio il mondo sie mosso nella direzione in cui il vincolo di una comunic... more Nell'ultimo decennio il mondo sie mosso nella direzione in cui il vincolo di una comunicazione ristretta a quella tramite cavi viene sciolto dalla possibilita, attraverso l'uso di tecnologie senza fili, di essere connessi ovunque ci si trovi. Il 2002e una data storica per ...
2013 9th International Wireless Communications and Mobile Computing Conference, IWCMC 2013, 2013
In this paper, we address the problem of reestablishing the network connectivity in post-disaster... more In this paper, we address the problem of reestablishing the network connectivity in post-disaster scenarios, where the original wireless infrastructure has been partitioned into multiple network fragments (called islands), operating on different frequencies. To this purpose, we propose the utilization of swarms of dedicated repairing units, called Stem-Nodes (SNs). SNs are provided with Cognitive Radio (CR) and self-positioning capabilities, in order to offer maximum reconfigurability in terms of mobility and wireless technologies supported. Moreover, swarms of SNs can self-organize into STEM-Mesh structure, that works as a dynamic backbone to connect heterogeneous islands using different technologies (e.g. Wi-Fi, Wi-MAX, etc). In this paper, we present three contributions pertaining to STEM-Mesh: (i) we describe a distributed motion control scheme (based on virtual springs approach) that enables SNs to self-organize into dynamic STEM-Mesh structures, (ii) we introduce a discovery scheme, through which SNs can explore the scenario in both spatial and frequency domains, and possibly connect the islands to the STEM-Mesh backbone and (iii) we validate the correctness of the proposed scheme, by verifying the optimal placements of the SNs composing the STEM-Mesh on a simplified scenario (e.g. chain topology). Finally, we evaluate through Omnet++ simulations the ability of STEM-Mesh to maximally re-establish connectivity on partitioned network scenarios.
ABSTRACT The heterogeneity of current telecommunication access technologies is dramatically incre... more ABSTRACT The heterogeneity of current telecommunication access technologies is dramatically increasing the complexity and costs required for the set-up and maintenance of the network by service providers, and it is also posing important limitations in terms of network interoperability from the end-users' perspectives. For these reasons, research on wireless systems has investigated the possibility to deploy wireless devices with self-organizing and self-managing capabilities. However, most of these approaches limit the re-configuration capabilities to a specific layer (e.g. routing), and do not investigate the property of reconfiguration of the network as a whole. In this paper, we propose an alternative architecture (called STEM-Net) for network infrastructure deployment, extension, and management. In STEM-Net self-organization is managed through fully-reconfigurable wireless devices (called stem-nodes), that can undergo mutations to fulfill a specific tasks, like their biological counterpart. In this work we present the main characteristics of stem-nodes, and we discuss how their evolutionary behaviour can result in an extreme flexibility of the whole network segment, transforming the technological heterogeneity from a limitation to a richness.
Computer Communications, 2015
Nowadays, spontaneous wireless networks enabled by mobile end-user devices (e.g. smartphones or t... more Nowadays, spontaneous wireless networks enabled by mobile end-user devices (e.g. smartphones or tablets) are receiving considerable interest due the possibility to offer a wide range of novel, highly pervasive and user-centric network services and applications. In this paper, we focus on emergency-related scenarios, and we investigate the potential of spontaneous networks for providing Internet connectivity over the emergency area through the sharing of resources owned by the end-user devices. Novel and extremely flexible network deployment strategies are required in order to cope with the user mobility, the limited communication capabilities of wireless devices, and the intrinsic dinamicity of traffic loads and QoS requirements. To this purpose, we propose here a novel approach toward the deployment of spontaneous networks composed by a new generation of wireless devices -called Stem Nodes (SNs) to emphasize their ability to cover multiple network roles (e.g. gateway, router). The self-organization of the spontaneous network is then achieved through the local reconfiguration of each SN. Two complementary research contributions are provided. First, we describe the software architecture of a SN (which can be implemented on top of existing end-user devices), and we detail how a SN can manage its role set, eventually extending it through cooperation with other SNs. Second, we propose distributed algorithms, based on swarm intelligence principles, through which each SN can autonously select its role, and self-elect to gateways or routers, so that end-to-end performance are maximized while the lifetime of the spontaneous emergency network is prolonged. The ability of the proposed algorithm to guarantee adaptive and self-organizing network behaviours is demostrated through extensive Omnet++ simulations, and through a prototype implementation of the SN architecture on a real testbed.
2013 Future Network Mobile Summit, 2013
ABSTRACT The heterogeneity of current telecommunication access technologies is dramatically incre... more ABSTRACT The heterogeneity of current telecommunication access technologies is dramatically increasing the complexity and costs required for the set-up and maintenance of the network by service providers, and it is also posing important limitations in terms of network interoperability from the end-users' perspectives. For these reasons, research on wireless systems has investigated the possibility to deploy wireless devices with self-organizing and self-managing capabilities. However, most of these approaches limit the re-configuration capabilities to a specific layer (e.g. routing), and do not investigate the property of reconfiguration of the network as a whole. In this paper, we propose an alternative architecture (called STEM-Net) for network infrastructure deployment, extension, and management. In STEM-Net self-organization is managed through fully-reconfigurable wireless devices (called stem-nodes), that can undergo mutations to fulfill a specific tasks, like their biological counterpart. In this work we present the main characteristics of stem-nodes, and we discuss how their evolutionary behaviour can result in an extreme flexibility of the whole network segment, transforming the technological heterogeneity from a limitation to a richness.
Nowadays several mobile applications connect to the internet through 2G/3G/LTE, which are becomin... more Nowadays several mobile applications connect to the internet through 2G/3G/LTE, which are becoming more crowded. Cognitive wireless networks have been proposed as a possible solution to supply additional bandwidth, and more recently TV White Spaces (TVWS) have been investigated as one candidate. TVWS devices should contact a remote spectrum database, which will reply with the channels available to use. It is not specified how devices should contact the remote spectrum database, so in this work we focus on the usage of a cellular connection, where however the number of the queries could rapidly grow and occupy considerable bandwidth. In this paper we present the idea of Femto-Databases, i.e. devices which act as distributed mobile databases able to satisfy the spectrum requests by opportunistic devices. Extensive simulations through the Omnet++ platform show that our approach can effectively reduce the load on the cellular infrastructure, and improve the latency of the query communication to the remote spectrum database.
2014 IEEE 25th Annual International Symposium on Personal, Indoor, and Mobile Radio Communication (PIMRC), 2014
Computer Communications, 2015
Nowadays, spontaneous wireless networks enabled by mobile end-user devices (e.g. smartphones or t... more Nowadays, spontaneous wireless networks enabled by mobile end-user devices (e.g. smartphones or tablets) are receiving considerable interest due the possibility to offer a wide range of novel, highly pervasive and user-centric network services and applications. In this paper, we focus on emergency-related scenarios, and we investigate the potential of spontaneous networks for providing Internet connectivity over the emergency area through the sharing of resources owned by the end-user devices. Novel and extremely flexible network deployment strategies are required in order to cope with the user mobility, the limited communication capabilities of wireless devices, and the intrinsic dinamicity of traffic loads and QoS requirements. To this purpose, we propose here a novel approach toward the deployment of spontaneous networks composed by a new generation of wireless devices -called Stem Nodes (SNs) to emphasize their ability to cover multiple network roles (e.g. gateway, router). The self-organization of the spontaneous network is then achieved through the local reconfiguration of each SN. Two complementary research contributions are provided. First, we describe the software architecture of a SN (which can be implemented on top of existing end-user devices), and we detail how a SN can manage its role set, eventually extending it through cooperation with other SNs. Second, we propose distributed algorithms, based on swarm intelligence principles, through which each SN can autonously select its role, and self-elect to gateways or routers, so that end-to-end performance are maximized while the lifetime of the spontaneous emergency network is prolonged. The ability of the proposed algorithm to guarantee adaptive and self-organizing network behaviours is demostrated through extensive Omnet++ simulations, and through a prototype implementation of the SN architecture on a real testbed.
2014 IEEE 80th Vehicular Technology Conference (VTC2014-Fall), 2014
Nowadays several mobile applications connect to the internet through 2G/3G/LTE, which are becomin... more Nowadays several mobile applications connect to the internet through 2G/3G/LTE, which are becoming more crowded. Cognitive wireless networks have been proposed as a possible solution to supply additional bandwidth, and more recently TV White Spaces (TVWS) have been investigated as one candidate. TVWS devices should contact a remote spectrum database, which will reply with the channels available to use. It is not specified how devices should contact the remote spectrum database, so in this work we focus on the usage of a cellular connection, where however the number of the queries could rapidly grow and occupy considerable bandwidth. In this paper we present the idea of Femto-Databases, i.e. devices which act as distributed mobile databases able to satisfy the spectrum requests by opportunistic devices. Extensive simulations through the Omnet++ platform show that our approach can effectively reduce the load on the cellular infrastructure, and improve the latency of the query communication to the remote spectrum database.
2013 9th International Wireless Communications and Mobile Computing Conference, IWCMC 2013, 2013
In this paper, we address the problem of reestablishing the network connectivity in post-disaster... more In this paper, we address the problem of reestablishing the network connectivity in post-disaster scenarios, where the original wireless infrastructure has been partitioned into multiple network fragments (called islands), operating on different frequencies. To this purpose, we propose the utilization of swarms of dedicated repairing units, called Stem-Nodes (SNs). SNs are provided with Cognitive Radio (CR) and self-positioning capabilities, in order to offer maximum reconfigurability in terms of mobility and wireless technologies supported. Moreover, swarms of SNs can self-organize into STEM-Mesh structure, that works as a dynamic backbone to connect heterogeneous islands using different technologies (e.g. Wi-Fi, Wi-MAX, etc). In this paper, we present three contributions pertaining to STEM-Mesh: (i) we describe a distributed motion control scheme (based on virtual springs approach) that enables SNs to self-organize into dynamic STEM-Mesh structures, (ii) we introduce a discovery scheme, through which SNs can explore the scenario in both spatial and frequency domains, and possibly connect the islands to the STEM-Mesh backbone and (iii) we validate the correctness of the proposed scheme, by verifying the optimal placements of the SNs composing the STEM-Mesh on a simplified scenario (e.g. chain topology). Finally, we evaluate through Omnet++ simulations the ability of STEM-Mesh to maximally re-establish connectivity on partitioned network scenarios.
In the aftermath of a natural calamity, relief operations can be hindered by damages to the terre... more In the aftermath of a natural calamity, relief operations can be hindered by damages to the terrestrial infrastructures (e.g. cellular base stations) that might lead to the disruption of wireless communication services. As a result, network partitions made up of isolated End-User (EU) devices, heterogeneous in terms of wireless access technologies and transmitting frequency bands, can occur within the scenario. In this paper, we address the problem of how to deploy a temporary and dynamic wireless network in order to quickly re-establish the end-to-end connectivity among isolated devices in a post-disaster environment. To this purpose, we propose the utilization of Repairing Units (RUs), consisting of Unmanned Ground Vehicles (UGVs) equipped with multiple Cognitive Radio (CR) devices; swarms of RUs are able to self-organize into a Repairing Mesh Network (RMN) that connects the isolated EU devices. Three main contributions are provided in this paper. First, we address the theoretical problem of determining the optimal deployment of the RMN (in terms of position and channel allocation on each RU), so that the number of connected EU devices is maximized, given a constrained number of available RUs. We further divide the deployment problem into a multi-channel spatial coverage and mesh connectivity problems, and we provide an approximated (optimal) solution. Second, we propose a distributed algorithm—based on the virtual spring force model—through which the RUs are able to explore the scenario in terms of space/frequency, and to create the RMN. Third, we evaluate connectivity and adaptiveness of the distributed solution through extensive Omnet++ simulations and a small scale test-bed. Simulation results show that the distributed RMN deployment algorithm provides performance close to the approximated solution in terms of covered EU devices. Experimental results demonstrate the ability of the distributed virtual spring model to adapt to dynamic propagation conditions, in order to maximize the quality of the wireless links of the RMN.
Machine-to-Machine communications is envisioned to become one of the fundamental pillars of the f... more Machine-to-Machine communications is envisioned to become one of the fundamental pillars of the future Internet of Things paradigm, enabling platoons of devices to be seamlessly connected and to cooperate over smart spaces. Among the possible application scenarios, smart metering represents an already existing technology that might take benefit from the capability of autonomous configuration and setup of M2M networks. At present, smart meters communicate over the 2G/3G network, however the utilization of the cellular technology poses several problems, such as low coverage and spectrum shortage over dense areas. To overcome these issues, in this paper we investigate the application of cognitive radio principles over TV White Spaces to M2M communication for the smart metering scenario. Following the recent regulations of FCC and Ofcom, that foresees the presence of a spectrum database for TV white spaces detection, we study the trade-off between protection of licensees and energy consumption in a cluster of smart meters. We provide three novel research contributions: (i) an analytical model to estimate the lifetime of a cluster of smart meters; (ii) centralized and distributed algorithms to determine the schedule operations of Master/Slave devices foreseen by the spectrum regulations; (iii) performance evaluation of the proposed framework through extensive Omnet++ simulations.
Machine-to-Machine communications is envisioned to become one of the fundamental pillars of the f... more Machine-to-Machine communications is envisioned to become one of the fundamental pillars of the future Internet of Things paradigm, enabling platoons of devices to be seamlessly connected and to cooperate over smart spaces. Among the possible application scenarios, smart metering represents an already existing technology that might take benefit from the capability of autonomous configuration and setup of M2M networks. At present, smart meters communicate over the 2G/3G network, however the utilization of the cellular technology poses several problems, such as low coverage and spectrum shortage over dense areas. To overcome these issues, in this paper we investigate the application of cognitive radio principles over TV White Spaces to M2M communication for the smart metering scenario. Following the recent regulations of FCC and Ofcom, that foresees the presence of a spectrum database for TV white spaces detection, we study the trade-off between protection of licensees and energy consumption in a cluster of smart meters. We provide three novel research contributions: (i) an analytical model to estimate the lifetime of a cluster of smart meters; (ii) centralized and distributed algorithms to determine the schedule operations of Master/Slave devices foreseen by the spectrum regulations; (iii) performance evaluation of the proposed framework through extensive Omnet++ simulations.
Spontaneous networks among end-user devices (e.g. smartphones, tablets) can guarantee emergency c... more Spontaneous networks among end-user devices (e.g. smartphones, tablets) can guarantee emergency communication in post-disaster scenarios where the original infrastructure has been partially damaged by the occurrence of unpredictable or catastrophic events. However, the heterogeneity of devices and wireless access technologies poses important challenges on the network deployment and management. In this paper, we propose the STEM-Net architecture as a viable network model to handle the devices' heterogeneity and to enable spontaneous networking functionalities in post-disaster scenarios. In STEM-Net, the wireless devices -called Stem Nodes (SN)-are able to adapt their transmitting configurations, cover different roles (e.g. router, bridge, etc) according to the system needs and evolve their functionalities through cooperation with other nodes. Here, we provide a proof-of-concept of the principles of nodes' mutation and evolution, by discussing how heterogeneous end-user devices provided with SN capabilities can dynamically self-organize into multi-hop networks, and share the Internet access by switching among three roles: stub, transit and gateway SNs. A bio-inspired distributed gateway selection mode is proposed to allow each SN device to decide its current role, based on the system needs and on the individual hardware characteristics and resources (e.g. residual energy or queue occupation). The simulation analysis conducted with the Omnet++ tool demonstrates the effectiveness of the STEM-Net framework in prolonging the network lifetime while providing adequate bandwidth for emergency communication to the end-users devices.
Computer Communications, 2015
Nowadays, spontaneous wireless networks enabled by mobile end-user devices (e.g. smartphones or t... more Nowadays, spontaneous wireless networks enabled by mobile end-user devices (e.g. smartphones or tablets) are receiving considerable interest due the possibility to offer a wide range of novel, highly pervasive and user-centric network services and applications. In this paper, we focus on emergency-related scenarios, and we investigate the potential of spontaneous networks for providing Internet connectivity over the emergency area through the sharing of resources owned by the end-user devices. Novel and extremely flexible network deployment strategies are required in order to cope with the user mobility, the limited communication capabilities of wireless devices, and the intrinsic dinamicity of traffic loads and QoS requirements. To this purpose, we propose here a novel approach toward the deployment of spontaneous networks composed by a new generation of wireless devices -called Stem Nodes (SNs) to emphasize their ability to cover multiple network roles (e.g. gateway, router). The self-organization of the spontaneous network is then achieved through the local reconfiguration of each SN. Two complementary research contributions are provided. First, we describe the software architecture of a SN (which can be implemented on top of existing end-user devices), and we detail how a SN can manage its role set, eventually extending it through cooperation with other SNs. Second, we propose distributed algorithms, based on swarm intelligence principles, through which each SN can autonously select its role, and self-elect to gateways or routers, so that end-to-end performance are maximized while the lifetime of the spontaneous emergency network is prolonged. The ability of the proposed algorithm to guarantee adaptive and self-organizing network behaviours is demostrated through extensive Omnet++ simulations, and through a prototype implementation of the SN architecture on a real testbed.
After the digital TV switch-over, national spectrum regulators are considering opportunistic sp... more After the digital TV switch-over, national spectrum regulators are considering opportunistic spectrum access techniques in the TV White Spaces (TVWS) frequency band. At present, the reference solution envisages the utilization of geolocation spectrum databases (GLDBs), in which spectrum availability is computed through complex propagation models. However, recent studies indicate that the used path loss model in GLDBs could be either inaccurate or too much conservative, possibly reducing the use of TVWS for opportunistic use by secondary networks. In this paper, we investigate the possibility to enhance the estimation accuracy of GLDBs with sensing reports produced by a swarm of Unmanned Aerial Scanning Vehicles (UASVs). These latter are able to explore the scenario in both space and frequencies, and to build a fine-grained shadowing map which can be used to tune the accuracy of propagation model used by GLDB. A novel distributed mobility algorithm is described for the sensing coverage of the scenario, and an aggregation mechanism for the map creation is illustrated. Simulation results confirm the effectiveness of our scheme in terms of TVWS detection accuracy and scenario coverage issues.
2013 9th International Wireless Communications and Mobile Computing Conference, IWCMC 2013, 2013
In this paper, we address the problem of reestablishing the network connectivity in post-disaster... more In this paper, we address the problem of reestablishing the network connectivity in post-disaster scenarios, where the original wireless infrastructure has been partitioned into multiple network fragments (called islands), operating on different frequencies. To this purpose, we propose the utilization of swarms of dedicated repairing units, called Stem-Nodes (SNs). SNs are provided with Cognitive Radio (CR) and self-positioning capabilities, in order to offer maximum reconfigurability in terms of mobility and wireless technologies supported. Moreover, swarms of SNs can self-organize into STEM-Mesh structure, that works as a dynamic backbone to connect heterogeneous islands using different technologies (e.g. Wi-Fi, Wi-MAX, etc). In this paper, we present three contributions pertaining to STEM-Mesh: (i) we describe a distributed motion control scheme (based on virtual springs approach) that enables SNs to self-organize into dynamic STEM-Mesh structures, (ii) we introduce a discovery scheme, through which SNs can explore the scenario in both spatial and frequency domains, and possibly connect the islands to the STEM-Mesh backbone and (iii) we validate the correctness of the proposed scheme, by verifying the optimal placements of the SNs composing the STEM-Mesh on a simplified scenario (e.g. chain topology). Finally, we evaluate through Omnet++ simulations the ability of STEM-Mesh to maximally re-establish connectivity on partitioned network scenarios.
Spontaneous networks among end-user devices (e.g. smartphones, tablets) can guarantee emergency c... more Spontaneous networks among end-user devices (e.g. smartphones, tablets) can guarantee emergency communication in post-disaster scenarios where the original infrastructure has been partially damaged by the occurrence of unpredictable or catastrophic events. However, the heterogeneity of devices and wireless access technologies poses important challenges on the network deployment and management. In this paper, we propose the STEM-Net architecture as a viable network model to handle the devices' heterogeneity and to enable spontaneous networking functionalities in post-disaster scenarios. In STEM-Net, the wireless devices -called Stem Nodes (SN)-are able to adapt their transmitting configurations, cover different roles (e.g. router, bridge, etc) according to the system needs and evolve their functionalities through cooperation with other nodes. Here, we provide a proof-of-concept of the principles of nodes' mutation and evolution, by discussing how heterogeneous end-user devices provided with SN capabilities can dynamically self-organize into multi-hop networks, and share the Internet access by switching among three roles: stub, transit and gateway SNs. A bio-inspired distributed gateway selection mode is proposed to allow each SN device to decide its current role, based on the system needs and on the individual hardware characteristics and resources (e.g. residual energy or queue occupation). The simulation analysis conducted with the Omnet++ tool demonstrates the effectiveness of the STEM-Net framework in prolonging the network lifetime while providing adequate bandwidth for emergency communication to the end-users devices.
Nell'ultimo decennio il mondo sie mosso nella direzione in cui il vincolo di una comunic... more Nell'ultimo decennio il mondo sie mosso nella direzione in cui il vincolo di una comunicazione ristretta a quella tramite cavi viene sciolto dalla possibilita, attraverso l'uso di tecnologie senza fili, di essere connessi ovunque ci si trovi. Il 2002e una data storica per ...
2013 9th International Wireless Communications and Mobile Computing Conference, IWCMC 2013, 2013
In this paper, we address the problem of reestablishing the network connectivity in post-disaster... more In this paper, we address the problem of reestablishing the network connectivity in post-disaster scenarios, where the original wireless infrastructure has been partitioned into multiple network fragments (called islands), operating on different frequencies. To this purpose, we propose the utilization of swarms of dedicated repairing units, called Stem-Nodes (SNs). SNs are provided with Cognitive Radio (CR) and self-positioning capabilities, in order to offer maximum reconfigurability in terms of mobility and wireless technologies supported. Moreover, swarms of SNs can self-organize into STEM-Mesh structure, that works as a dynamic backbone to connect heterogeneous islands using different technologies (e.g. Wi-Fi, Wi-MAX, etc). In this paper, we present three contributions pertaining to STEM-Mesh: (i) we describe a distributed motion control scheme (based on virtual springs approach) that enables SNs to self-organize into dynamic STEM-Mesh structures, (ii) we introduce a discovery scheme, through which SNs can explore the scenario in both spatial and frequency domains, and possibly connect the islands to the STEM-Mesh backbone and (iii) we validate the correctness of the proposed scheme, by verifying the optimal placements of the SNs composing the STEM-Mesh on a simplified scenario (e.g. chain topology). Finally, we evaluate through Omnet++ simulations the ability of STEM-Mesh to maximally re-establish connectivity on partitioned network scenarios.
ABSTRACT The heterogeneity of current telecommunication access technologies is dramatically incre... more ABSTRACT The heterogeneity of current telecommunication access technologies is dramatically increasing the complexity and costs required for the set-up and maintenance of the network by service providers, and it is also posing important limitations in terms of network interoperability from the end-users' perspectives. For these reasons, research on wireless systems has investigated the possibility to deploy wireless devices with self-organizing and self-managing capabilities. However, most of these approaches limit the re-configuration capabilities to a specific layer (e.g. routing), and do not investigate the property of reconfiguration of the network as a whole. In this paper, we propose an alternative architecture (called STEM-Net) for network infrastructure deployment, extension, and management. In STEM-Net self-organization is managed through fully-reconfigurable wireless devices (called stem-nodes), that can undergo mutations to fulfill a specific tasks, like their biological counterpart. In this work we present the main characteristics of stem-nodes, and we discuss how their evolutionary behaviour can result in an extreme flexibility of the whole network segment, transforming the technological heterogeneity from a limitation to a richness.
Computer Communications, 2015
Nowadays, spontaneous wireless networks enabled by mobile end-user devices (e.g. smartphones or t... more Nowadays, spontaneous wireless networks enabled by mobile end-user devices (e.g. smartphones or tablets) are receiving considerable interest due the possibility to offer a wide range of novel, highly pervasive and user-centric network services and applications. In this paper, we focus on emergency-related scenarios, and we investigate the potential of spontaneous networks for providing Internet connectivity over the emergency area through the sharing of resources owned by the end-user devices. Novel and extremely flexible network deployment strategies are required in order to cope with the user mobility, the limited communication capabilities of wireless devices, and the intrinsic dinamicity of traffic loads and QoS requirements. To this purpose, we propose here a novel approach toward the deployment of spontaneous networks composed by a new generation of wireless devices -called Stem Nodes (SNs) to emphasize their ability to cover multiple network roles (e.g. gateway, router). The self-organization of the spontaneous network is then achieved through the local reconfiguration of each SN. Two complementary research contributions are provided. First, we describe the software architecture of a SN (which can be implemented on top of existing end-user devices), and we detail how a SN can manage its role set, eventually extending it through cooperation with other SNs. Second, we propose distributed algorithms, based on swarm intelligence principles, through which each SN can autonously select its role, and self-elect to gateways or routers, so that end-to-end performance are maximized while the lifetime of the spontaneous emergency network is prolonged. The ability of the proposed algorithm to guarantee adaptive and self-organizing network behaviours is demostrated through extensive Omnet++ simulations, and through a prototype implementation of the SN architecture on a real testbed.
2013 Future Network Mobile Summit, 2013
ABSTRACT The heterogeneity of current telecommunication access technologies is dramatically incre... more ABSTRACT The heterogeneity of current telecommunication access technologies is dramatically increasing the complexity and costs required for the set-up and maintenance of the network by service providers, and it is also posing important limitations in terms of network interoperability from the end-users' perspectives. For these reasons, research on wireless systems has investigated the possibility to deploy wireless devices with self-organizing and self-managing capabilities. However, most of these approaches limit the re-configuration capabilities to a specific layer (e.g. routing), and do not investigate the property of reconfiguration of the network as a whole. In this paper, we propose an alternative architecture (called STEM-Net) for network infrastructure deployment, extension, and management. In STEM-Net self-organization is managed through fully-reconfigurable wireless devices (called stem-nodes), that can undergo mutations to fulfill a specific tasks, like their biological counterpart. In this work we present the main characteristics of stem-nodes, and we discuss how their evolutionary behaviour can result in an extreme flexibility of the whole network segment, transforming the technological heterogeneity from a limitation to a richness.
Nowadays several mobile applications connect to the internet through 2G/3G/LTE, which are becomin... more Nowadays several mobile applications connect to the internet through 2G/3G/LTE, which are becoming more crowded. Cognitive wireless networks have been proposed as a possible solution to supply additional bandwidth, and more recently TV White Spaces (TVWS) have been investigated as one candidate. TVWS devices should contact a remote spectrum database, which will reply with the channels available to use. It is not specified how devices should contact the remote spectrum database, so in this work we focus on the usage of a cellular connection, where however the number of the queries could rapidly grow and occupy considerable bandwidth. In this paper we present the idea of Femto-Databases, i.e. devices which act as distributed mobile databases able to satisfy the spectrum requests by opportunistic devices. Extensive simulations through the Omnet++ platform show that our approach can effectively reduce the load on the cellular infrastructure, and improve the latency of the query communication to the remote spectrum database.
2014 IEEE 25th Annual International Symposium on Personal, Indoor, and Mobile Radio Communication (PIMRC), 2014
Computer Communications, 2015
Nowadays, spontaneous wireless networks enabled by mobile end-user devices (e.g. smartphones or t... more Nowadays, spontaneous wireless networks enabled by mobile end-user devices (e.g. smartphones or tablets) are receiving considerable interest due the possibility to offer a wide range of novel, highly pervasive and user-centric network services and applications. In this paper, we focus on emergency-related scenarios, and we investigate the potential of spontaneous networks for providing Internet connectivity over the emergency area through the sharing of resources owned by the end-user devices. Novel and extremely flexible network deployment strategies are required in order to cope with the user mobility, the limited communication capabilities of wireless devices, and the intrinsic dinamicity of traffic loads and QoS requirements. To this purpose, we propose here a novel approach toward the deployment of spontaneous networks composed by a new generation of wireless devices -called Stem Nodes (SNs) to emphasize their ability to cover multiple network roles (e.g. gateway, router). The self-organization of the spontaneous network is then achieved through the local reconfiguration of each SN. Two complementary research contributions are provided. First, we describe the software architecture of a SN (which can be implemented on top of existing end-user devices), and we detail how a SN can manage its role set, eventually extending it through cooperation with other SNs. Second, we propose distributed algorithms, based on swarm intelligence principles, through which each SN can autonously select its role, and self-elect to gateways or routers, so that end-to-end performance are maximized while the lifetime of the spontaneous emergency network is prolonged. The ability of the proposed algorithm to guarantee adaptive and self-organizing network behaviours is demostrated through extensive Omnet++ simulations, and through a prototype implementation of the SN architecture on a real testbed.
2014 IEEE 80th Vehicular Technology Conference (VTC2014-Fall), 2014
Nowadays several mobile applications connect to the internet through 2G/3G/LTE, which are becomin... more Nowadays several mobile applications connect to the internet through 2G/3G/LTE, which are becoming more crowded. Cognitive wireless networks have been proposed as a possible solution to supply additional bandwidth, and more recently TV White Spaces (TVWS) have been investigated as one candidate. TVWS devices should contact a remote spectrum database, which will reply with the channels available to use. It is not specified how devices should contact the remote spectrum database, so in this work we focus on the usage of a cellular connection, where however the number of the queries could rapidly grow and occupy considerable bandwidth. In this paper we present the idea of Femto-Databases, i.e. devices which act as distributed mobile databases able to satisfy the spectrum requests by opportunistic devices. Extensive simulations through the Omnet++ platform show that our approach can effectively reduce the load on the cellular infrastructure, and improve the latency of the query communication to the remote spectrum database.
2013 9th International Wireless Communications and Mobile Computing Conference, IWCMC 2013, 2013
In this paper, we address the problem of reestablishing the network connectivity in post-disaster... more In this paper, we address the problem of reestablishing the network connectivity in post-disaster scenarios, where the original wireless infrastructure has been partitioned into multiple network fragments (called islands), operating on different frequencies. To this purpose, we propose the utilization of swarms of dedicated repairing units, called Stem-Nodes (SNs). SNs are provided with Cognitive Radio (CR) and self-positioning capabilities, in order to offer maximum reconfigurability in terms of mobility and wireless technologies supported. Moreover, swarms of SNs can self-organize into STEM-Mesh structure, that works as a dynamic backbone to connect heterogeneous islands using different technologies (e.g. Wi-Fi, Wi-MAX, etc). In this paper, we present three contributions pertaining to STEM-Mesh: (i) we describe a distributed motion control scheme (based on virtual springs approach) that enables SNs to self-organize into dynamic STEM-Mesh structures, (ii) we introduce a discovery scheme, through which SNs can explore the scenario in both spatial and frequency domains, and possibly connect the islands to the STEM-Mesh backbone and (iii) we validate the correctness of the proposed scheme, by verifying the optimal placements of the SNs composing the STEM-Mesh on a simplified scenario (e.g. chain topology). Finally, we evaluate through Omnet++ simulations the ability of STEM-Mesh to maximally re-establish connectivity on partitioned network scenarios.
In the aftermath of a natural calamity, relief operations can be hindered by damages to the terre... more In the aftermath of a natural calamity, relief operations can be hindered by damages to the terrestrial infrastructures (e.g. cellular base stations) that might lead to the disruption of wireless communication services. As a result, network partitions made up of isolated End-User (EU) devices, heterogeneous in terms of wireless access technologies and transmitting frequency bands, can occur within the scenario. In this paper, we address the problem of how to deploy a temporary and dynamic wireless network in order to quickly re-establish the end-to-end connectivity among isolated devices in a post-disaster environment. To this purpose, we propose the utilization of Repairing Units (RUs), consisting of Unmanned Ground Vehicles (UGVs) equipped with multiple Cognitive Radio (CR) devices; swarms of RUs are able to self-organize into a Repairing Mesh Network (RMN) that connects the isolated EU devices. Three main contributions are provided in this paper. First, we address the theoretical problem of determining the optimal deployment of the RMN (in terms of position and channel allocation on each RU), so that the number of connected EU devices is maximized, given a constrained number of available RUs. We further divide the deployment problem into a multi-channel spatial coverage and mesh connectivity problems, and we provide an approximated (optimal) solution. Second, we propose a distributed algorithm—based on the virtual spring force model—through which the RUs are able to explore the scenario in terms of space/frequency, and to create the RMN. Third, we evaluate connectivity and adaptiveness of the distributed solution through extensive Omnet++ simulations and a small scale test-bed. Simulation results show that the distributed RMN deployment algorithm provides performance close to the approximated solution in terms of covered EU devices. Experimental results demonstrate the ability of the distributed virtual spring model to adapt to dynamic propagation conditions, in order to maximize the quality of the wireless links of the RMN.
Machine-to-Machine communications is envisioned to become one of the fundamental pillars of the f... more Machine-to-Machine communications is envisioned to become one of the fundamental pillars of the future Internet of Things paradigm, enabling platoons of devices to be seamlessly connected and to cooperate over smart spaces. Among the possible application scenarios, smart metering represents an already existing technology that might take benefit from the capability of autonomous configuration and setup of M2M networks. At present, smart meters communicate over the 2G/3G network, however the utilization of the cellular technology poses several problems, such as low coverage and spectrum shortage over dense areas. To overcome these issues, in this paper we investigate the application of cognitive radio principles over TV White Spaces to M2M communication for the smart metering scenario. Following the recent regulations of FCC and Ofcom, that foresees the presence of a spectrum database for TV white spaces detection, we study the trade-off between protection of licensees and energy consumption in a cluster of smart meters. We provide three novel research contributions: (i) an analytical model to estimate the lifetime of a cluster of smart meters; (ii) centralized and distributed algorithms to determine the schedule operations of Master/Slave devices foreseen by the spectrum regulations; (iii) performance evaluation of the proposed framework through extensive Omnet++ simulations.
Machine-to-Machine communications is envisioned to become one of the fundamental pillars of the f... more Machine-to-Machine communications is envisioned to become one of the fundamental pillars of the future Internet of Things paradigm, enabling platoons of devices to be seamlessly connected and to cooperate over smart spaces. Among the possible application scenarios, smart metering represents an already existing technology that might take benefit from the capability of autonomous configuration and setup of M2M networks. At present, smart meters communicate over the 2G/3G network, however the utilization of the cellular technology poses several problems, such as low coverage and spectrum shortage over dense areas. To overcome these issues, in this paper we investigate the application of cognitive radio principles over TV White Spaces to M2M communication for the smart metering scenario. Following the recent regulations of FCC and Ofcom, that foresees the presence of a spectrum database for TV white spaces detection, we study the trade-off between protection of licensees and energy consumption in a cluster of smart meters. We provide three novel research contributions: (i) an analytical model to estimate the lifetime of a cluster of smart meters; (ii) centralized and distributed algorithms to determine the schedule operations of Master/Slave devices foreseen by the spectrum regulations; (iii) performance evaluation of the proposed framework through extensive Omnet++ simulations.
Spontaneous networks among end-user devices (e.g. smartphones, tablets) can guarantee emergency c... more Spontaneous networks among end-user devices (e.g. smartphones, tablets) can guarantee emergency communication in post-disaster scenarios where the original infrastructure has been partially damaged by the occurrence of unpredictable or catastrophic events. However, the heterogeneity of devices and wireless access technologies poses important challenges on the network deployment and management. In this paper, we propose the STEM-Net architecture as a viable network model to handle the devices' heterogeneity and to enable spontaneous networking functionalities in post-disaster scenarios. In STEM-Net, the wireless devices -called Stem Nodes (SN)-are able to adapt their transmitting configurations, cover different roles (e.g. router, bridge, etc) according to the system needs and evolve their functionalities through cooperation with other nodes. Here, we provide a proof-of-concept of the principles of nodes' mutation and evolution, by discussing how heterogeneous end-user devices provided with SN capabilities can dynamically self-organize into multi-hop networks, and share the Internet access by switching among three roles: stub, transit and gateway SNs. A bio-inspired distributed gateway selection mode is proposed to allow each SN device to decide its current role, based on the system needs and on the individual hardware characteristics and resources (e.g. residual energy or queue occupation). The simulation analysis conducted with the Omnet++ tool demonstrates the effectiveness of the STEM-Net framework in prolonging the network lifetime while providing adequate bandwidth for emergency communication to the end-users devices.