2012
Anifantis, E.; Karyotis, V.; Papavassiliou, S.
A Markov Random Field framework for channel assignment in Cognitive Radio networks Conference
Lugano, 2012, ISBN: 9781467309073, (cited By 14; Conference of 2012 IEEE International Conference on Pervasive Computing and Communications Workshops, PERCOM Workshops 2012 ; Conference Date: 19 March 2012 Through 23 March 2012; Conference Code:89907).
Abstract | Links | BibTeX | Tags: Cognitive radio; Image segmentation; Radio systems; Ubiquitous computing; Wireless telecommunication systems, Wireless networks
@conference{Anifantis2012770,
title = {A Markov Random Field framework for channel assignment in Cognitive Radio networks},
author = {E. Anifantis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861557370&doi=10.1109%2fPerComW.2012.6197617&partnerID=40&md5=b61b3a30d3184b4e48a981017504ed6c},
doi = {10.1109/PerComW.2012.6197617},
isbn = {9781467309073},
year = {2012},
date = {2012-01-01},
journal = {2012 IEEE International Conference on Pervasive Computing and Communications Workshops, PERCOM Workshops 2012},
pages = {770-775},
address = {Lugano},
abstract = {In order to alleviate the absence of hierarchical coordination among secondary users of Cognitive Radio networks and to enable fast and efficient reconfiguration of pervasive ad hoc networks, spatially localized and frequency agile mechanisms are required across the wireless protocol stack. In this paper, we introduce a framework for distributed and adaptable radio channel allocation in wireless Cognitive Radio networks, which is based on the theory of Markov Random Fields and Gibbs sampling. By exchanging local only information, secondary users are able to assign efficiently available channels according to desired operational requirements, even if these requirements change over time. Through analysis and simulation we show the applicability of the framework and demonstrate its distributed operation. We study the emerging trade-offs of the proposed approach by demonstrating the performance benefits obtained in radio channel allocation and by analyzing the inherent costs. © 2012 IEEE.},
note = {cited By 14; Conference of 2012 IEEE International Conference on Pervasive Computing and Communications Workshops, PERCOM Workshops 2012 ; Conference Date: 19 March 2012 Through 23 March 2012; Conference Code:89907},
keywords = {Cognitive radio; Image segmentation; Radio systems; Ubiquitous computing; Wireless telecommunication systems, Wireless networks},
pubstate = {published},
tppubtype = {conference}
}
In order to alleviate the absence of hierarchical coordination among secondary users of Cognitive Radio networks and to enable fast and efficient reconfiguration of pervasive ad hoc networks, spatially localized and frequency agile mechanisms are required across the wireless protocol stack. In this paper, we introduce a framework for distributed and adaptable radio channel allocation in wireless Cognitive Radio networks, which is based on the theory of Markov Random Fields and Gibbs sampling. By exchanging local only information, secondary users are able to assign efficiently available channels according to desired operational requirements, even if these requirements change over time. Through analysis and simulation we show the applicability of the framework and demonstrate its distributed operation. We study the emerging trade-offs of the proposed approach by demonstrating the performance benefits obtained in radio channel allocation and by analyzing the inherent costs. © 2012 IEEE.
Stai, E.; Karyotis, V.; Papavassiliou, S.
Topology enhancements in wireless multihop networks: A top-down approach Journal Article
In: IEEE Transactions on Parallel and Distributed Systems, vol. 23, no. 7, pp. 1344-1357, 2012, ISSN: 10459219, (cited By 16).
Abstract | Links | BibTeX | Tags: Continuum mechanics; Energy utilization; Topology, Network evolution; Network science; Online social networks; Topology control; Wireless multi-hop network, Wireless networks
@article{Stai20121344,
title = {Topology enhancements in wireless multihop networks: A top-down approach},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861741202&doi=10.1109%2fTPDS.2011.250&partnerID=40&md5=0254f54df82f0e88a0a260e40d8ab384},
doi = {10.1109/TPDS.2011.250},
issn = {10459219},
year = {2012},
date = {2012-01-01},
journal = {IEEE Transactions on Parallel and Distributed Systems},
volume = {23},
number = {7},
pages = {1344-1357},
abstract = {Contemporary traffic demands call for efficient infrastructures capable of sustaining increasing volumes of social communications. In this work, we focus on improving the properties of wireless multihop networks with social features through network evolution. Specifically, we introduce a framework, based on inverse Topology Control (iTC), for distributively modifying the transmission radius of selected nodes, according to social paradigms. Distributed iTC mechanisms are proposed for exploiting evolutionary network churn in the form of edge/node modifications, without significantly impacting available resources. We employ continuum theory for analytically describing the proposed top-down approach of infusing social features in physical topologies. Through simulations, we demonstrate how these mechanisms achieve their goal of reducing the average path length, so as to make a wireless multihop network scale like a social one, while retaining its original multihop character. We study the impact of the proposed topology modifications on the operation and performance of the network with respect to the average throughput, delay, and energy consumption of the induced network. © 2012 IEEE.},
note = {cited By 16},
keywords = {Continuum mechanics; Energy utilization; Topology, Network evolution; Network science; Online social networks; Topology control; Wireless multi-hop network, Wireless networks},
pubstate = {published},
tppubtype = {article}
}
Contemporary traffic demands call for efficient infrastructures capable of sustaining increasing volumes of social communications. In this work, we focus on improving the properties of wireless multihop networks with social features through network evolution. Specifically, we introduce a framework, based on inverse Topology Control (iTC), for distributively modifying the transmission radius of selected nodes, according to social paradigms. Distributed iTC mechanisms are proposed for exploiting evolutionary network churn in the form of edge/node modifications, without significantly impacting available resources. We employ continuum theory for analytically describing the proposed top-down approach of infusing social features in physical topologies. Through simulations, we demonstrate how these mechanisms achieve their goal of reducing the average path length, so as to make a wireless multihop network scale like a social one, while retaining its original multihop character. We study the impact of the proposed topology modifications on the operation and performance of the network with respect to the average throughput, delay, and energy consumption of the induced network. © 2012 IEEE.
2011
Stai, E.; Karyotis, V.; Papavassiliou, S.
Enhancing trust establishment in wireless multi-hop networks via preferential attachment Conference
Corfu, 2011, ISSN: 15301346, (cited By 0; Conference of 16th IEEE Symposium on Computers and Communications, ISCC'11 ; Conference Date: 28 June 2011 Through 1 July 2011; Conference Code:86395).
Abstract | Links | BibTeX | Tags: Continuum mechanics; Topology, Multihop networks; Network Science; Topology Control; Trust establishment; Trusted Paths, Wireless networks
@conference{Stai2011630,
title = {Enhancing trust establishment in wireless multi-hop networks via preferential attachment},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80052746899&doi=10.1109%2fISCC.2011.5983909&partnerID=40&md5=e95d4225c4ab66999437fc5a93e04a0a},
doi = {10.1109/ISCC.2011.5983909},
issn = {15301346},
year = {2011},
date = {2011-01-01},
journal = {Proceedings - IEEE Symposium on Computers and Communications},
pages = {630-635},
address = {Corfu},
abstract = {In this paper the problem of enhancing trust establishment in multi-hop wireless networks is addressed. Exploiting small-world features and based on preferential attachment and initial node trust values, we design inverse Topology Control methods that achieve to reduce the mean hop-distance between two nodes and increase the average trust value of the shortest paths. Based on continuum theory a mathematical framework is developed for the overall socially-motivated trust-based network churn mechanism. Analytical and simulation results exhibit the effectiveness of the proposed approaches for enhancing physical topologies, increasing the average trust path values, and thus further securing future communications systems. © 2011 IEEE.},
note = {cited By 0; Conference of 16th IEEE Symposium on Computers and Communications, ISCC'11 ; Conference Date: 28 June 2011 Through 1 July 2011; Conference Code:86395},
keywords = {Continuum mechanics; Topology, Multihop networks; Network Science; Topology Control; Trust establishment; Trusted Paths, Wireless networks},
pubstate = {published},
tppubtype = {conference}
}
In this paper the problem of enhancing trust establishment in multi-hop wireless networks is addressed. Exploiting small-world features and based on preferential attachment and initial node trust values, we design inverse Topology Control methods that achieve to reduce the mean hop-distance between two nodes and increase the average trust value of the shortest paths. Based on continuum theory a mathematical framework is developed for the overall socially-motivated trust-based network churn mechanism. Analytical and simulation results exhibit the effectiveness of the proposed approaches for enhancing physical topologies, increasing the average trust path values, and thus further securing future communications systems. © 2011 IEEE.
Karyotis, V.; Fazio, M.; Papavassiliou, S.; Puliafito, A.
Comparison of efficient random walk strategies for wireless multi-hop networks Journal Article
In: Computer Communications, vol. 34, no. 10, pp. 1258-1267, 2011, ISSN: 01403664, (cited By 4).
Abstract | Links | BibTeX | Tags: Cover time; Energy consumption; Hybrid random walks; Multihop networks; Topology awareness, Energy utilization; Military applications; Quality of service; Random processes; Topology, Wireless networks
@article{Karyotis20111258,
title = {Comparison of efficient random walk strategies for wireless multi-hop networks},
author = {V. Karyotis and M. Fazio and S. Papavassiliou and A. Puliafito},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79955708234&doi=10.1016%2fj.comcom.2011.01.001&partnerID=40&md5=06a7f2bacc2f23dd6cbd25c27205ee8b},
doi = {10.1016/j.comcom.2011.01.001},
issn = {01403664},
year = {2011},
date = {2011-01-01},
journal = {Computer Communications},
volume = {34},
number = {10},
pages = {1258-1267},
abstract = {Wireless multi-hop networks have drawn great attention from research and business communities, since they suit well diverse application scenarios, such as environmental monitoring, military support in hostile environments and emergency applications. However, this challenging communication paradigm requires solutions able to fit specific requirements in terms of resource constrains, node mobility and quality of service. Random Walks (RWs) are probabilistic approaches to perform distributed operations, such as data search and retrieval. They are effective and have relatively small overhead compared to classic schemes, such as flooding. To further improve performance of RWs, hybrid solutions may be employed. Such strategies increase system performance at the cost of additional energy consumption. In this work, we propose two novel schemes that exploit local topological information in order to increase the hybrid RW protocols performance. Through simulations, we compare hybrid protocols with a traditional RW solution, studying their performance in static and mobile scenarios. An analysis of the trade-off between the number of node revisits and energy consumption allows to identify the more fitting protocols for different application scenarios in wireless multi-hop networks. Advantages and drawbacks of different RW strategies are highlighted, along with research challenges that need to be investigated in the future. © 2011 Elsevier B.V. All rights reserved.},
note = {cited By 4},
keywords = {Cover time; Energy consumption; Hybrid random walks; Multihop networks; Topology awareness, Energy utilization; Military applications; Quality of service; Random processes; Topology, Wireless networks},
pubstate = {published},
tppubtype = {article}
}
Wireless multi-hop networks have drawn great attention from research and business communities, since they suit well diverse application scenarios, such as environmental monitoring, military support in hostile environments and emergency applications. However, this challenging communication paradigm requires solutions able to fit specific requirements in terms of resource constrains, node mobility and quality of service. Random Walks (RWs) are probabilistic approaches to perform distributed operations, such as data search and retrieval. They are effective and have relatively small overhead compared to classic schemes, such as flooding. To further improve performance of RWs, hybrid solutions may be employed. Such strategies increase system performance at the cost of additional energy consumption. In this work, we propose two novel schemes that exploit local topological information in order to increase the hybrid RW protocols performance. Through simulations, we compare hybrid protocols with a traditional RW solution, studying their performance in static and mobile scenarios. An analysis of the trade-off between the number of node revisits and energy consumption allows to identify the more fitting protocols for different application scenarios in wireless multi-hop networks. Advantages and drawbacks of different RW strategies are highlighted, along with research challenges that need to be investigated in the future. © 2011 Elsevier B.V. All rights reserved.
2010
Karyotis, V.; Pittalà, F.; Fazio, M.; Papavassiliou, S.; Puliafito, A.
Topology-aware hybrid random walk protocols for wireless multihop networks Journal Article
In: Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, vol. 32 LNICST, pp. 107-118, 2010, ISSN: 18678211, (cited By 2; Conference of 1st International Conference on Mobile Networks and Management, MONAMI 2009 ; Conference Date: 13 October 2009 Through 14 October 2009; Conference Code:86048).
Abstract | Links | BibTeX | Tags: Computer simulation; MESH networking; Network management; Random processes; Sensor networks; Topology, Wireless networks
@article{Karyotis2010107,
title = {Topology-aware hybrid random walk protocols for wireless multihop networks},
author = {V. Karyotis and F. Pittalà and M. Fazio and S. Papavassiliou and A. Puliafito},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84885893498&doi=10.1007%2f978-3-642-11817-3_10&partnerID=40&md5=90023c1d624d4f2bb70f6f595786f39c},
doi = {10.1007/978-3-642-11817-3_10},
issn = {18678211},
year = {2010},
date = {2010-01-01},
journal = {Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering},
volume = {32 LNICST},
pages = {107-118},
address = {Athens},
abstract = {The proliferation of wireless multihop networks has made various operations, such as search and retrieval of distributed data a significant concern. Various methods have been proposed for performing such tasks efficiently, especially when all network nodes need to be visited at least once. Random walks are probabilistic approaches for performing the aforementioned operations effectively and with relatively small overhead compared to other typically-employed schemes, such as flooding. Recently, a hybrid random walk scheme has been proposed for increasing the desired performance, at the cost of additional consumed resources. In this work, we adopt the paradigm of hybrid random walk protocols and propose two novel hybrid schemes that exploit local topological information, aiming at further increasing the performance of random walk protocols in multihop networks. We consider different jump configurations of the hybrid random walk protocols and various degrees of mobility. Through analysis and simulation, the simple random walk model appears more appropriate for energy-constrained networks such as sensor networks, while the hybrid ones are more appealing for less energy-stringent, performance-oriented multihop networks, such as vehicular and mesh networks. The simple hybrid protocol occupies the middle ground, being appealing for ad hoc networks with medium to low node densities and average energy requirements. © 2010 ICST Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering.},
note = {cited By 2; Conference of 1st International Conference on Mobile Networks and Management, MONAMI 2009 ; Conference Date: 13 October 2009 Through 14 October 2009; Conference Code:86048},
keywords = {Computer simulation; MESH networking; Network management; Random processes; Sensor networks; Topology, Wireless networks},
pubstate = {published},
tppubtype = {article}
}
The proliferation of wireless multihop networks has made various operations, such as search and retrieval of distributed data a significant concern. Various methods have been proposed for performing such tasks efficiently, especially when all network nodes need to be visited at least once. Random walks are probabilistic approaches for performing the aforementioned operations effectively and with relatively small overhead compared to other typically-employed schemes, such as flooding. Recently, a hybrid random walk scheme has been proposed for increasing the desired performance, at the cost of additional consumed resources. In this work, we adopt the paradigm of hybrid random walk protocols and propose two novel hybrid schemes that exploit local topological information, aiming at further increasing the performance of random walk protocols in multihop networks. We consider different jump configurations of the hybrid random walk protocols and various degrees of mobility. Through analysis and simulation, the simple random walk model appears more appropriate for energy-constrained networks such as sensor networks, while the hybrid ones are more appealing for less energy-stringent, performance-oriented multihop networks, such as vehicular and mesh networks. The simple hybrid protocol occupies the middle ground, being appealing for ad hoc networks with medium to low node densities and average energy requirements. © 2010 ICST Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering.
Stai, E.; Karyotis, V.; Papavassiliou, S.
Socially-inspired topology improvements in wireless multi-hop networks Conference
Capetown, 2010, ISBN: 9781424468263, (cited By 9; Conference of 2010 IEEE International Conference on Communications Workshops, ICC 2010 ; Conference Date: 23 May 2010 Through 27 May 2010; Conference Code:81220).
Abstract | Links | BibTeX | Tags: Communication; Computer simulation; Continuum mechanics; Topology; Wireless telecommunication systems, Wireless networks
@conference{Stai2010,
title = {Socially-inspired topology improvements in wireless multi-hop networks},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77954942474&doi=10.1109%2fICCW.2010.5503927&partnerID=40&md5=82086b2738485e0a51209225fb489b8f},
doi = {10.1109/ICCW.2010.5503927},
isbn = {9781424468263},
year = {2010},
date = {2010-01-01},
journal = {2010 IEEE International Conference on Communications Workshops, ICC 2010},
address = {Capetown},
abstract = {Several graph structures have emerged for describing different network types and the interactions among their entities. Various properties have been identified in each of these network graphs, with no single structure bearing all the desired features that would constitute it an optimal network graph. This work aims for the first time at infusing the desired properties of a small-world network into the core structure of a wireless multi-hop network, thus embedding social structure on an artificial network that emerges in the development of wireless communication services. In this paper, topology control based approaches are proposed, serving the purpose of adding communication links in a multi-hop network in an intelligent and effective manner. Through analysis and simulation, we demonstrate how the proposed methods decrease the average path length between randomly selected node pairs and properly scale the clustering coefficient of a multi-hop network, by exploiting social structure characteristics of small-world networks, thus allowing the development of more demanding services on top of wireless multi-hop networks. ©2010 IEEE.},
note = {cited By 9; Conference of 2010 IEEE International Conference on Communications Workshops, ICC 2010 ; Conference Date: 23 May 2010 Through 27 May 2010; Conference Code:81220},
keywords = {Communication; Computer simulation; Continuum mechanics; Topology; Wireless telecommunication systems, Wireless networks},
pubstate = {published},
tppubtype = {conference}
}
Several graph structures have emerged for describing different network types and the interactions among their entities. Various properties have been identified in each of these network graphs, with no single structure bearing all the desired features that would constitute it an optimal network graph. This work aims for the first time at infusing the desired properties of a small-world network into the core structure of a wireless multi-hop network, thus embedding social structure on an artificial network that emerges in the development of wireless communication services. In this paper, topology control based approaches are proposed, serving the purpose of adding communication links in a multi-hop network in an intelligent and effective manner. Through analysis and simulation, we demonstrate how the proposed methods decrease the average path length between randomly selected node pairs and properly scale the clustering coefficient of a multi-hop network, by exploiting social structure characteristics of small-world networks, thus allowing the development of more demanding services on top of wireless multi-hop networks. ©2010 IEEE.