@article{Sarigiannidis2015651,

title = {On the use of learning automata in tuning the channel split ratio of WiMAX networks},

author = { A.G. Sarigiannidis and P. Nicopolitidis and G.I. Papadimitriou and P.G. Sarigiannidis and M.D. Louta and A.S. Pomportsis},

url = {https://www.researchgate.net/publication/259965818_On_the_Use_of_Learning_Automata_in_Tuning_the_Channel_Split_Ratio_of_WiMAX_Networks?_sg=n136X9gc9StHToProYGXLZS-jwpMWkwXOcutOZjrnuvav1Dkx2j8jDAYH2U1EttqBO-qyvaiEoSFzSk},

doi = {10.1109/JSYST.2013.2282032},

year  = {2015},

date = {2015-01-01},

journal = {IEEE Systems Journal},

volume = {9},

number = {3},

pages = {651-663},

abstract = {The Worldwide Interoperability for Microwave Access (WiMAX) family of standards have introduced a flexible, efficient, and robust wireless interface. Among other interesting features, WiMAX access networks bring into play a flexible determination of the ratio between the downlink and uplink directions, allowing a relation width from 3: 1 to 1: 1, respectively. However, this promising feature is not properly utilized, since hitherto scheduling and mapping schemes proposed neglect it. In this paper, this challenging issue is effectively addressed by proposing an adaptive model that attempts to adequately adjust the downlink-to-uplink subframe width ratio according to the current traffic conditions. In the context of a mobile WiMAX wireless access network, the base station is enhanced with an error-aware learning automaton in order to be able to identify the magnitude of the incoming and outgoing traffic flows and, in turn, to suitably define the ratio on a frame-by-frame basis. The model designed is extensively evaluated under realistic and dynamic scenarios, and the results indicate that its performance is clearly improved compared with schemes having predefined and fixed ratio values. © 2007-2012 IEEE.},

keywords = {IEEE 802.16, learning automata (LA), mapping, orthogonal frequency-division multiple access (OFDMA), Worldwide Interoperability for Microwave Access (WiMAX)},

pubstate = {published},

tppubtype = {article}

}

@article{Kraounakis2015878,

title = {A Robust Reputation-Based Computational Model for Trust Establishment in Pervasive Systems},

author = { S. Kraounakis and I.N. Demetropoulos and A. Michalas and M.S. Obaidat and P.G. Sarigiannidis and M.D. Louta},

url = {https://www.researchgate.net/publication/278737556_A_Robust_Reputation-Based_Computational_Model_for_Trust_Establishment_in_Pervasive_Systems},

doi = {10.1109/JSYST.2014.2345912},

year  = {2015},

date = {2015-01-01},

journal = {IEEE Systems Journal},

volume = {9},

number = {3},

pages = {878-891},

abstract = {Distributed systems built in open competitive and highly dynamic pervasive environments are composed of autonomous entities that act and interact in an intelligent and flexible manner so as to achieve their own goals and aims. System entities may be classified into two main categories that are, in principle, in conflict. These are the service resource requestors (SRRs) wishing to use services and/or exploit resources offered by the other system entities and the service resource providers (SRPs) that offer the services/resources requested. Seeking for the maximization of their welfare, entities may misbehave, thus leading to a significant deterioration of system's performance. The scope of this paper is to present a computational model for trust establishment based on a reputation mechanism, which incorporates direct SRRs' experiences and information disseminated from witness SRRs on the basis of their past experiences with SRPs. The designed mechanism discriminates between unfair feedback ratings intentionally and unintentionally provided, takes into consideration potential changes to providers' behavior, and weighs more recent events in the evaluation of the overall reputation ratings. The proposed model has been extensively evaluated through simulation experiments. It exhibits good performance, as the reputation computation error introduced due to false feedback provision decreases significantly. © 2007-2012 IEEE.},

keywords = {Collaborative reputation mechanism, intelligent multiagent systems, pervasive systems, trust management systems},

pubstate = {published},

tppubtype = {article}

}

@article{Sarigiannidis2015427,

title = {Architectures and Bandwidth Allocation Schemes for Hybrid Wireless-Optical Networks},

author = { A.G. Sarigiannidis and M. Iloridou and P. Nicopolitidis and G. Papadimitriou and F.-N. Pavlidou and P.G. Sarigiannidis and M.D. Louta and V. Vitsas},

url = {https://www.researchgate.net/publication/273792922_Architectures_and_Bandwidth_Allocation_Schemes_for_Hybrid_Wireless-Optical_Networks?_sg=Ubu-c9MVnMKQCG9WEfRFKa3Wd26kQdcSp4_xLD8X1dD_RizLK1cy2D7cEwMylTdpH03-cKk38_B5pT0},

doi = {10.1109/COMST.2014.2356640},

year  = {2015},

date = {2015-01-01},

journal = {IEEE Communications Surveys and Tutorials},

volume = {17},

number = {1},

pages = {427-468},

abstract = {The combination of the most prestigious optical and wireless technologies for implementing a modern broadband integrated access network has been progressively gaining ground. By extending the network coverage in a cost-efficient way, hybrid wireless-optical networks are able to enclose a larger number of potential subscribers than standalone access architectures. Hence, they are capable of increasing revenue levels and facilitating commercial penetration to the telecom market. At the same time, hybrid wireless-optical networks pose an ambitious, alternative, and efficient solution to coping with new bandwidth-hungry user applications. Hybrid wireless-optical networks incorporate sophisticated modules, fabrics, and network entities to effectively provide adequate quality of service (QoS) provisioning. This survey endeavors to classify the main features of wireless-optical integration. We provide a comprehensive compilation of the latest architectures, integrated technologies, QoS features, and dynamic bandwidth allocation (DBA) schemes. In addition, new trends towards wireless-optical convergence are presented. Moreover, as the up-to-date hybrid network standards remain under development, since there is not yet an integrated standard for approving hybrid network access platforms, we accompany this survey with detailed challenges indicating potential avenues of future research. © 1998-2012 IEEE.},

keywords = {Access networks, DBA, FiWi, hybrid wireless-optical, integrated architectures, LTE, Passive optical networks, WiFi, WiMAX},

pubstate = {published},

tppubtype = {article}

}

@article{Sarigiannidis20157560,

title = {Detecting Sybil attacks in wireless sensor networks using UWB ranging-based information},

author = { P. Sarigiannidis and E. Karapistoli and A.A. Economides},

url = {https://www.researchgate.net/publication/279153588_Detecting_Sybil_Attacks_in_Wireless_Sensor_Networks_using_UWB_Ranging-based_Information?_sg=8HafLwH09h8CvldAKWBSwxdP1uPr4CVat2Xutl6381pf9s5GybAmhWbTDwL3Y4fLD9wOI6trjwQ6MWI},

doi = {10.1016/j.eswa.2015.05.057},

year  = {2015},

date = {2015-01-01},

journal = {Expert Systems with Applications},

volume = {42},

number = {21},

pages = {7560-7572},

abstract = {Security is becoming a major concern for many mission-critical applications wireless sensor networks (WSNs) are envisaged to support. The inherently vulnerable characteristics of WSNs appoint them susceptible to various types of attacks. This work restrains its focus on how to defend against a particularly harmful form of attack, the Sybil attack. Sybil attacks can severely deteriorate the network performance and compromise the security by disrupting many networking protocols. This paper presents a rule-based anomaly detection system, called RADS, which monitors and timely detects Sybil attacks in large-scale WSNs. At its core, the proposed expert system relies on an ultra-wideband (UWB) ranging-based detection algorithm that operates in a distributed manner requiring no cooperation or information sharing between the sensor nodes in order to perform the anomaly detection tasks. The feasibility of the proposed approach is proven analytically, while the performance of RADS in exposing Sybil attacks is extensively assessed both mathematically and numerically. The obtained results demonstrate that RADS achieves high detection accuracy and low false alarm rate appointing it a promising ADS candidate for this class of wireless networks. © 2015 Elsevier Ltd. All rights reserved.},

keywords = {Detection probability analysis, Rule-based anomaly detection system, Ultra-wideband (UWB) radio technology, UWB ranging-based Sybil attack detection, wireless sensor networks},

pubstate = {published},

tppubtype = {article}

}

@article{Mavridopoulos2015470,

title = {Broadcast Levels: Efficient and Lightweight Schedule Construction for Push-Based Data Broadcasting Systems},

author = { S. Mavridopoulos and P. Nicopolitidis and G. Papadimitriou and P. Sarigiannidis},

url = {https://www.researchgate.net/publication/279770864_Broadcast_Levels_Efficient_and_Lightweight_Schedule_Construction_for_Push-Based_Data_Broadcasting_Systems?_sg=0j_ejC8-35oRtU2DLJIJKl7iGe88YpazLBtSgzLPGJ8-cvUO2V89ykQQXbEwvStZzzVlda7jumqwv90},

doi = {10.1109/TBC.2015.2444334},

year  = {2015},

date = {2015-01-01},

journal = {IEEE Transactions on Broadcasting},

volume = {61},

number = {3},

pages = {470-481},

abstract = {In wireless push-based systems traffic is asymmetric meaning that the server has much more bandwidth available, as compared to the clients. Since it is often not possible or desirable for the clients to send any requests, the server should broadcast the data periodically. The performance of this system relies heavily on the proper scheduling of the broadcast data. The well known algorithm proposed by Vaidya and Hameed battles this challenge and achieves state-of-the-art performance. However, this performance comes with a computational complexity linear to the number of data items that are broadcast. Furthermore, Vaidya's and Hameed's proposed solution for this time complexity degenerates performance. This paper proposes a scheduling algorithm for wireless push-based data broadcasting systems, which performs near optimal and has low computational complexity. Performance evaluation results are presented to demonstrate its efficient performance despite its low computational demands. © 1963-12012 IEEE.},

keywords = {adaptive, Broadcast, low computational complexity, multiple channels, push-based system, wireless},

pubstate = {published},

tppubtype = {article}

}

@article{Panagiotakis20151628,

title = {Performance Increase for Highly-Loaded RoF Access Networks},

author = { A. Panagiotakis and P. Nicopolitidis and G.I. Papadimitriou and P.G. Sarigiannidis},

url = {https://www.researchgate.net/publication/281768938_Performance_Increase_for_Highly-Loaded_RoF_Access_Networks},

doi = {10.1109/LCOMM.2015.2456911},

year  = {2015},

date = {2015-01-01},

journal = {IEEE Communications Letters},

volume = {19},

number = {9},

pages = {1628-1631},

abstract = {This letter presents a medium access control (MAC) mechanism that allows for the effective use of the bandwidth of highly loaded 60 GHz Radio-over-Fiber (RoF) networks. We extend a previous approach proposed in the literature which is shown to have problems in highly-loaded cases. We propose a protocol that makes use of a memory buffer at the Central Office (CO) at the providers side that allows for the reduction of the number of polling packets required to identify all the active wireless nodes that need to transmit data. This greatly increases the overall throughput of the network at a maximum percentage of 42% for the examined configurations. The high throughput provided by our proposal is achieved without the need to update current infrastructure and only needs a trivial amount of memory at the provider's side. © 1997-2012 IEEE.},

keywords = {MAC protocols, Radio over Fiber, Wireless networking},

pubstate = {published},

tppubtype = {article}

}