Christos Bouras
Short CV: Christos Bouras is Professor in the University of Patras, Department of Computer Engineering and Informatics. Also he is a scientific advisor of Research Unit 6 in Computer Technology Institute and Press – Diophantus, Patras, Greece. His research interests include Analysis of Performance of Networking and Computer Systems, Computer Networks and Protocols, Mobile and Wireless Communications, Telematics and New Services, QoS and Pricing for Networks and Services, e-learning, Networked Virtual Environments and WWW Issues. He has extended professional experience in Design and Analysis of Networks, Protocols, Telematics and New Services. He has published more than 450 papers in various well-known refereed books, conferences and journals. He is a co-author of 9 books in Greek and editor of 2 in English. He has been member of editorial board for international journals and PC member and referee in various international journals and conferences. He has participated in R&D projects.
Journal Articles
Bouras, Christos; Kapoulas, Vaggelis; Tsanai, Enea
Efficient Mechanism and Performance Analysis of Routing Protocols in VANETs for Realistic Scenarios Journal Article
In: International Journal of Interdisciplinary Telecommunications and Networking, IGI Global, vol. 8, pp. 20-49, 2016.
Abstract | Links | BibTeX | Tags:
@article{4119,
title = {Efficient Mechanism and Performance Analysis of Routing Protocols in VANETs for Realistic Scenarios},
author = {Christos Bouras and Vaggelis Kapoulas and Enea Tsanai},
url = {https://telematics.upatras.gr/efficient-mechanisms-and-performance-analysis-of-routing-protocols-in-vanets-for-realistic-scenarios/},
year = {2016},
date = {2016-01-01},
urldate = {2016-01-01},
journal = {International Journal of Interdisciplinary Telecommunications and Networking, IGI Global},
volume = {8},
pages = {20-49},
abstract = {Vehicular Ad Hoc Networks (VANETs) are considered as a special case of mobile Ad Hoc Networks (MANETs) and are recently gaining a great attention from the research community. The need for improved road safety, traffic efficiency and direct communi-cation along with the great complexity in routing, makes VANETs a highly challeng-ing field. Routing in VANETs has to adapt to special characteristics such as high speed and road pattern movement as well as high linkage break probability. In this work, we show that traditional MANET routing protocols cannot efficiently handle the challeng-es in a VANET environment and thus need further modifications. For this reason, we propose and implement an enhancement mechanism, applied to the GPSR routing pro-tocol that adapts to the needs of a VANET. The proposed mechanism’s performance is evaluated through simulation sets for urban and highway scenarios and compared to the performance of the most common MANET routing protocols adopted in VANETs. The proposed enhancement is shown to be considerably beneficial and it significantly outperforms the rest of the tested routing protocols for almost every topology setting.},
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Vehicular Ad Hoc Networks (VANETs) are considered as a special case of mobile Ad Hoc Networks (MANETs) and are recently gaining a great attention from the research community. The need for improved road safety, traffic efficiency and direct communi-cation along with the great complexity in routing, makes VANETs a highly challeng-ing field. Routing in VANETs has to adapt to special characteristics such as high speed and road pattern movement as well as high linkage break probability. In this work, we show that traditional MANET routing protocols cannot efficiently handle the challeng-es in a VANET environment and thus need further modifications. For this reason, we propose and implement an enhancement mechanism, applied to the GPSR routing pro-tocol that adapts to the needs of a VANET. The proposed mechanism’s performance is evaluated through simulation sets for urban and highway scenarios and compared to the performance of the most common MANET routing protocols adopted in VANETs. The proposed enhancement is shown to be considerably beneficial and it significantly outperforms the rest of the tested routing protocols for almost every topology setting.
Bouras, Christos; Tsogkas, Vassilis
Assisting cluster coherency via N-grams and clustering as a tool to deal with the new user problem Journal Article
In: International Journal of Machine Learning and Cybernetics, Springer Verlang, vol. 7, pp. 171-184, 2016.
Abstract | Links | BibTeX | Tags:
@article{3437,
title = {Assisting cluster coherency via N-grams and clustering as a tool to deal with the new user problem},
author = {Christos Bouras and Vassilis Tsogkas},
url = {https://telematics.upatras.gr/ijmlc2016_bouras/},
year = {2016},
date = {2016-01-01},
urldate = {2016-01-01},
journal = {International Journal of Machine Learning and Cybernetics, Springer Verlang},
volume = {7},
pages = {171-184},
abstract = {Collaborative filtering systems typically need to acquire some data about the new user in order to start making personalized suggestions, a situation commonly referred to as the “new user problem”. In this work we attempt to address the new user problem via a unique personalized strategy for prompting the user with articles to rate. Our approach makes use of hypernyms extracted from the WordNet database and proves to be converging fast to the actual user interests based on minimal user ratings, which are provided during the registration process. In addition, we explore the possible enhancement of the document clustering results, and in particular clustering of news articles from the web, when using word-based n-grams during the keyword extraction phase. We present and evaluate a weighting approach that combines clustering of news articles derived from the web, using n-grams that are extracted from the articles at an offline stage. This technique is then compared with the single minded “bag-of-words” representation that our clustering algorithm, W-kmeans, previously used. Our experimentation reveals that via fine tuning the weighting parameters between keyword and n-grams, as well as the n value itself, a significant improvement regarding the clustering results metrics can be achieved.},
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Collaborative filtering systems typically need to acquire some data about the new user in order to start making personalized suggestions, a situation commonly referred to as the “new user problem”. In this work we attempt to address the new user problem via a unique personalized strategy for prompting the user with articles to rate. Our approach makes use of hypernyms extracted from the WordNet database and proves to be converging fast to the actual user interests based on minimal user ratings, which are provided during the registration process. In addition, we explore the possible enhancement of the document clustering results, and in particular clustering of news articles from the web, when using word-based n-grams during the keyword extraction phase. We present and evaluate a weighting approach that combines clustering of news articles derived from the web, using n-grams that are extracted from the articles at an offline stage. This technique is then compared with the single minded “bag-of-words” representation that our clustering algorithm, W-kmeans, previously used. Our experimentation reveals that via fine tuning the weighting parameters between keyword and n-grams, as well as the n value itself, a significant improvement regarding the clustering results metrics can be achieved.
Alexiou, Antonios; Bikos, Anastasios; Bilios, Dimitrios; Bouras, Christos
Power-Aware and QoS Provisioned Real Time Multimedia Transmission in Small Cell Networks Journal Article
In: International Journal of Wireless Networks and Broadband Technologies, IGI Global, vol. 5, pp. 24-45, 2016.
Abstract | Links | BibTeX | Tags:
@article{4130,
title = {Power-Aware and QoS Provisioned Real Time Multimedia Transmission in Small Cell Networks},
author = {Antonios Alexiou and Anastasios Bikos and Dimitrios Bilios and Christos Bouras},
url = {https://telematics.upatras.gr/viewcomplimentarytitle/},
year = {2016},
date = {2016-01-01},
urldate = {2016-01-01},
journal = {International Journal of Wireless Networks and Broadband Technologies, IGI Global},
volume = {5},
pages = {24-45},
abstract = {The recent emergence of ultra-high-speed and high-definition data and video services has pushed wireless network capacity to its limits. Cellular network capacity is therefore a valuable resource, whereas indoor coverage poses itself as a challenging issue. At the same time, real-world paradigms of multimedia transmission require effective Quality-of-Service (QoS) provisioning as well as power admission. To confront issues like delay-sensitive QoS requirements and traffic provisioning, as well as meet the mobile customer needs, this paper presents a traffic-aware Orthogonal Frequency-Division Multiple-Access (OFDMA) hybrid small-cell deployment for QoS provisioning and an optimal admission control strategy for 4G cellular systems. The traffic awareness in the proposed framework is provided by a utility function, which differentiates the traffic QoS levels with the user’s grouping priority indexes, channel conditions, and traffic characteristics. To further enhance the proposed framework, an admission power control algorithm based on an efficient algorithm handover is also proposed.},
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The recent emergence of ultra-high-speed and high-definition data and video services has pushed wireless network capacity to its limits. Cellular network capacity is therefore a valuable resource, whereas indoor coverage poses itself as a challenging issue. At the same time, real-world paradigms of multimedia transmission require effective Quality-of-Service (QoS) provisioning as well as power admission. To confront issues like delay-sensitive QoS requirements and traffic provisioning, as well as meet the mobile customer needs, this paper presents a traffic-aware Orthogonal Frequency-Division Multiple-Access (OFDMA) hybrid small-cell deployment for QoS provisioning and an optimal admission control strategy for 4G cellular systems. The traffic awareness in the proposed framework is provided by a utility function, which differentiates the traffic QoS levels with the user’s grouping priority indexes, channel conditions, and traffic characteristics. To further enhance the proposed framework, an admission power control algorithm based on an efficient algorithm handover is also proposed.
Asimakis, Konstantinos; Bouras, Christos; Kokkinos, Vasileios; Papazois, Andreas
Mobility - aware Power Control in MBSFN Journal Article
In: Telecommunications Systems, Springer Verlang (Special Issue on WMNC 2012), vol. 61, pp. 77-91, 2016.
Abstract | Links | BibTeX | Tags:
@article{3438,
title = {Mobility - aware Power Control in MBSFN},
author = {Konstantinos Asimakis and Christos Bouras and Vasileios Kokkinos and Andreas Papazois},
url = {https://telematics.upatras.gr/telsys2016_bouras/},
year = {2016},
date = {2016-01-01},
urldate = {2016-01-01},
journal = {Telecommunications Systems, Springer Verlang (Special Issue on WMNC 2012)},
volume = {61},
pages = {77-91},
abstract = {Multimedia Broadcast/Multicast Service (MBMS) over a Single Frequency Network (MBSFN) within LTE systems is a feature that allows synchronous broadcasting of common data among neighboring cells. With MBSFN operation, mobile broadcast/multicast users are able to use inter-cell interference in a constructive way and to achieve increased bit-rates compared to when conventional broadcasting is used. In this manuscript, we present our work on the optimization of the power control for future mobile networks that employ MBSFN transmission. We propose a novel simulator and system optimizer that can minimize the individual cell’s transmission power by taking into account the changing positions of users. The system optimizer is based on a novel genetic algorithm, which is resistant to entrapment in local optima and makes use of mutations over the previous solutions in order to optimize the power consumption given the new users’ positions. The optimizer’s engine can be used in conjunction with the simulator or can be easily modi ed to receive real-time measurements from a real LTE network as an input. In order to read descriptions of the various scenarios, the simulator uses the eXtendable Temporal Network Description Language (XTNDL), a language that is also speci ed in this manuscript.},
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Multimedia Broadcast/Multicast Service (MBMS) over a Single Frequency Network (MBSFN) within LTE systems is a feature that allows synchronous broadcasting of common data among neighboring cells. With MBSFN operation, mobile broadcast/multicast users are able to use inter-cell interference in a constructive way and to achieve increased bit-rates compared to when conventional broadcasting is used. In this manuscript, we present our work on the optimization of the power control for future mobile networks that employ MBSFN transmission. We propose a novel simulator and system optimizer that can minimize the individual cell’s transmission power by taking into account the changing positions of users. The system optimizer is based on a novel genetic algorithm, which is resistant to entrapment in local optima and makes use of mutations over the previous solutions in order to optimize the power consumption given the new users’ positions. The optimizer’s engine can be used in conjunction with the simulator or can be easily modi ed to receive real-time measurements from a real LTE network as an input. In order to read descriptions of the various scenarios, the simulator uses the eXtendable Temporal Network Description Language (XTNDL), a language that is also speci ed in this manuscript.
Bouras, Christos; Papazois, Andreas; Stasinos, Nikolaos
Cross-platform Mobile Applications with Web Technologies Journal Article
In: International Journal of Computing and Digital Systems, (Special Issue on MobiApps 2014), vol. 4, pp. 153-163, 2015.
Abstract | Links | BibTeX | Tags:
@article{4058,
title = {Cross-platform Mobile Applications with Web Technologies},
author = {Christos Bouras and Andreas Papazois and Nikolaos Stasinos},
url = {https://telematics.upatras.gr/paper-2/},
year = {2015},
date = {2015-01-01},
urldate = {2015-01-01},
journal = {International Journal of Computing and Digital Systems, (Special Issue on MobiApps 2014)},
volume = {4},
pages = {153-163},
abstract = {The extended use of smart mobile devices has become an integral part of daily life leading to the expansion of mobile application development. Currently, the majority of mobile applications are native applications that need an initial installation prior to being utilized. In addition, for a given application, a separate software development process could be required for each mobile platform, which subsequently increases dramatically the corresponding effort and cost. With the emergence of HTML5 these issues can be addressed efficiently, since web technologies allow the application development in a cross-platform manner. An important benefit is that users can have easy and immediate access the application without any need for downloading and installation. In this manuscript, we investigate the potentials of mobile application development with web technologies and we present a development framework that we have designed and implemented. This framework utilizes the most important state-of-art web technologies for the support of mobile devices. It can be used for the implementation of mobile web applications and also for the investigation and experimentation on the main features that HTML5 offers for this specific type of devices.},
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The extended use of smart mobile devices has become an integral part of daily life leading to the expansion of mobile application development. Currently, the majority of mobile applications are native applications that need an initial installation prior to being utilized. In addition, for a given application, a separate software development process could be required for each mobile platform, which subsequently increases dramatically the corresponding effort and cost. With the emergence of HTML5 these issues can be addressed efficiently, since web technologies allow the application development in a cross-platform manner. An important benefit is that users can have easy and immediate access the application without any need for downloading and installation. In this manuscript, we investigate the potentials of mobile application development with web technologies and we present a development framework that we have designed and implemented. This framework utilizes the most important state-of-art web technologies for the support of mobile devices. It can be used for the implementation of mobile web applications and also for the investigation and experimentation on the main features that HTML5 offers for this specific type of devices.
Antonis, Konstantinos; Bouras, Christos; D’Elia, Fabrizio; Vincenzo, Annalisa Di; Diles, Georgios; Kokkinos, Vasileios; Koskeris, Andreas
Broadband and e - Government Services in South East Europe: Comparative Analysis, Impact and Policy Recommendations Journal Article
In: International Journal of Interdisciplinary Telecommunications and Networking, IGI Global, vol. 6, pp. 39-56, 2015.
Abstract | Links | BibTeX | Tags:
@article{4060,
title = {Broadband and e - Government Services in South East Europe: Comparative Analysis, Impact and Policy Recommendations},
author = {Konstantinos Antonis and Christos Bouras and Fabrizio D’Elia and Annalisa Di Vincenzo and Georgios Diles and Vasileios Kokkinos and Andreas Koskeris},
url = {https://telematics.upatras.gr/broadband-and-e-government-services-in-south-east-europe_-comparative-analysis-impact-and-policy-recommendations/},
year = {2015},
date = {2015-01-01},
urldate = {2015-01-01},
journal = {International Journal of Interdisciplinary Telecommunications and Networking, IGI Global},
volume = {6},
pages = {39-56},
abstract = {The European Commission acknowledging the significance of broadband for the improvement of citizen welfare and its economic benefits, has put in place targets for the diffusion of broadband to all citizens and businesses in the European Union. This manuscript comparatively assesses the current state of affairs in broadband and digital public services in selected South East Europe (SEE) countries in order to identify weaknesses and highlight strengths, and attempts to measure the impact and effectiveness of broadband on the economy. To this direction, the authors focus on evaluating the correlation between broadband and growth and employment. They also estimate the savings achieved by the usage of e-services and the potential savings that will follow their increased utilization over the next years. The analysis is followed by a number of recommendations that aim to support informed decision making. The manuscript builds on four surveys that took place during the second quarter of 2013.},
keywords = {},
pubstate = {published},
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}
The European Commission acknowledging the significance of broadband for the improvement of citizen welfare and its economic benefits, has put in place targets for the diffusion of broadband to all citizens and businesses in the European Union. This manuscript comparatively assesses the current state of affairs in broadband and digital public services in selected South East Europe (SEE) countries in order to identify weaknesses and highlight strengths, and attempts to measure the impact and effectiveness of broadband on the economy. To this direction, the authors focus on evaluating the correlation between broadband and growth and employment. They also estimate the savings achieved by the usage of e-services and the potential savings that will follow their increased utilization over the next years. The analysis is followed by a number of recommendations that aim to support informed decision making. The manuscript builds on four surveys that took place during the second quarter of 2013.
Bouras, Christos; Kapoulas, Vaggelis; Kioumourtzis, Georgios; Stamos, Kostas; Stathopoulos, Nikos; Tavoularis, Nikolaos
A Signal Adaptation Mechanism for power optimization of wireless adapters Journal Article
In: International Journal of Wireless Networks and Broadband Technologies, IGI Global, vol. 4(3), pp. 48-72, 2015.
Abstract | Links | BibTeX | Tags:
@article{4107,
title = {A Signal Adaptation Mechanism for power optimization of wireless adapters},
author = {Christos Bouras and Vaggelis Kapoulas and Georgios Kioumourtzis and Kostas Stamos and Nikos Stathopoulos and Nikolaos Tavoularis},
url = {https://telematics.upatras.gr/a-signal-adaptation-mechanism-for-power-optimization-of-wireless-adapters/},
year = {2015},
date = {2015-01-01},
urldate = {2015-01-01},
journal = {International Journal of Wireless Networks and Broadband Technologies, IGI Global},
volume = {4(3)},
pages = {48-72},
abstract = {This manuscript introduces, implements and evaluates a feedback-based adaptation mechanism that adjusts the transmission power of a wireless card on commodity mobile devices. Main focus of this work is to minimize the power consumption by adjusting the transmission power of the wireless card, thus extending the battery life, while negative effects on connection quality are avoided. To achieve that, a mechanism that optimizes the power depending on the quality of the connection is presented, which measures the quality of the transmission and adjusts the transmission power, by utilizing an expanded array of metrics, for more accurate estimation. The mechanism has been implemented and tested on actual wireless adapters. In order to evaluate, fine-tune and improve the mechanism, a list of real environment experiments has been performed. The results indicate that power consumption can be significantly reduced for nodes that are either almost stationary or slowly moving, without any significant increase in packet loss.},
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This manuscript introduces, implements and evaluates a feedback-based adaptation mechanism that adjusts the transmission power of a wireless card on commodity mobile devices. Main focus of this work is to minimize the power consumption by adjusting the transmission power of the wireless card, thus extending the battery life, while negative effects on connection quality are avoided. To achieve that, a mechanism that optimizes the power depending on the quality of the connection is presented, which measures the quality of the transmission and adjusts the transmission power, by utilizing an expanded array of metrics, for more accurate estimation. The mechanism has been implemented and tested on actual wireless adapters. In order to evaluate, fine-tune and improve the mechanism, a list of real environment experiments has been performed. The results indicate that power consumption can be significantly reduced for nodes that are either almost stationary or slowly moving, without any significant increase in packet loss.
Bouras, Christos; Kanakis, Nikos; Kokkinos, Vasileios; Papazois, Andreas
Deploying AL-FEC Protection with Online Algorithms for Multicast Services over Cellular Networks Journal Article
In: Wireless Networks, Springer Verlang, vol. 20, pp. 2109-2122, 2015.
Abstract | Links | BibTeX | Tags:
@article{3436,
title = {Deploying AL-FEC Protection with Online Algorithms for Multicast Services over Cellular Networks},
author = {Christos Bouras and Nikos Kanakis and Vasileios Kokkinos and Andreas Papazois},
url = {https://telematics.upatras.gr/art_10-1007_s11276-014-0734-x/},
year = {2015},
date = {2015-01-01},
urldate = {2015-01-01},
journal = {Wireless Networks, Springer Verlang},
volume = {20},
pages = {2109-2122},
abstract = {Reliability control is a key concern on the evolution of mobile multicast services. To this direction, the use of forward error correction (FEC) on the application layer is widely adopted in several mobile multicast standards. FEC is a feedback free error control method, where the transmitter introduces in advance redundant information within the source data to enable receivers recovering arbitrary data erasures. On multicast delivery where retransmission-based error recovery methods are not ecient, the most suitable error control method is the use of application layer forward error correction (AL-FEC) codes. In this work, we introduce novel AL-FEC deployment policies over mobile multicast environments utilizing online algorithms. We aim at the ecient application of AL-FEC protection with RaptorQ codes over multicast delivery in the context of competitive analysis. We provide a competitiveness analysis model of AL-FEC application over mobile multicast environments. Furthermore, we propose two online algorithms adjusting the introduced redundancy of AL-FEC protection according to several FEC encoding parameters and constraints of mobile multicast delivery.},
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Reliability control is a key concern on the evolution of mobile multicast services. To this direction, the use of forward error correction (FEC) on the application layer is widely adopted in several mobile multicast standards. FEC is a feedback free error control method, where the transmitter introduces in advance redundant information within the source data to enable receivers recovering arbitrary data erasures. On multicast delivery where retransmission-based error recovery methods are not ecient, the most suitable error control method is the use of application layer forward error correction (AL-FEC) codes. In this work, we introduce novel AL-FEC deployment policies over mobile multicast environments utilizing online algorithms. We aim at the ecient application of AL-FEC protection with RaptorQ codes over multicast delivery in the context of competitive analysis. We provide a competitiveness analysis model of AL-FEC application over mobile multicast environments. Furthermore, we propose two online algorithms adjusting the introduced redundancy of AL-FEC protection according to several FEC encoding parameters and constraints of mobile multicast delivery.
Gkamas, Apostolos; Bouras, Christos; Kioumourtzis, G
Mobile Ad hoc networks (MANETs) for multimedia transmission Journal Article
In: vol. 9, pp. 6239-6248, 2015.
Abstract | Links | BibTeX | Tags:
@article{3434,
title = {Mobile Ad hoc networks (MANETs) for multimedia transmission},
author = {Apostolos Gkamas and Christos Bouras and G Kioumourtzis},
url = {https://telematics.upatras.gr/mobile-ad-hoc-networks-manets-for-multimedia-transmission-2/},
year = {2015},
date = {2015-01-01},
urldate = {2015-01-01},
volume = {9},
pages = {6239-6248},
publisher = {Encyclopedia of Information Science and Technology (3rd Ed.), IGI Global},
edition = {3rd},
chapter = {614},
abstract = {Mobile Ad hoc Networks (MANETs) are becoming more essential to wireless communications due to growing popularity of mobile devices. A node in MANETs could act as a router while having also the possibility of being the sender or receiver of information. MANETs offer the freedom to use mobile devices and move independently of the location of base stations (and outside their coverage) with the help of other network devices. The ability of MANETs to be self-configured and form a mobile mesh network, by using wireless links, make them very suitable for a number of cases that other type of networks cannot operate. In addition, MANETs do not require vast technological investments. An ideal application area for the utilization of MANET technology is for instance any disaster scenario in which the fixed infrastructure is incapacitated or non-existent. In this case it is important to ensure that a suitable communication solution is established within the very first critical hours of an incident, considering national or cross-border emergency incidents. What is missing, however, from this type of networks is the so called a “killer application” that could boost its utilizations in the real world. Real time multimedia applications have the potential to turn MANETs into a very attractive solution in wireless networks taking into account its unique characteristics. Our motivation for this article is to present the shortcomings and the current state of the art in MANETs in regards to the transmission of multimedia data, which is a promising application area.},
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Mobile Ad hoc Networks (MANETs) are becoming more essential to wireless communications due to growing popularity of mobile devices. A node in MANETs could act as a router while having also the possibility of being the sender or receiver of information. MANETs offer the freedom to use mobile devices and move independently of the location of base stations (and outside their coverage) with the help of other network devices. The ability of MANETs to be self-configured and form a mobile mesh network, by using wireless links, make them very suitable for a number of cases that other type of networks cannot operate. In addition, MANETs do not require vast technological investments. An ideal application area for the utilization of MANET technology is for instance any disaster scenario in which the fixed infrastructure is incapacitated or non-existent. In this case it is important to ensure that a suitable communication solution is established within the very first critical hours of an incident, considering national or cross-border emergency incidents. What is missing, however, from this type of networks is the so called a “killer application” that could boost its utilizations in the real world. Real time multimedia applications have the potential to turn MANETs into a very attractive solution in wireless networks taking into account its unique characteristics. Our motivation for this article is to present the shortcomings and the current state of the art in MANETs in regards to the transmission of multimedia data, which is a promising application area.
Bouras, Christos; Antonis, Konstantinos; Diles, Georgios; Kokkinos, Vasileios; Loukopoulos, Leonidas
Economic Broadband Development through Infrastructure Sharing Journal Article
In: International Journal of Business Data Communications and Networking, IGI Global, vol. 10, pp. 21-42, 2014.
Abstract | Links | BibTeX | Tags:
@article{4106,
title = {Economic Broadband Development through Infrastructure Sharing},
author = {Christos Bouras and Konstantinos Antonis and Georgios Diles and Vasileios Kokkinos and Leonidas Loukopoulos},
url = {https://telematics.upatras.gr/economic-broadband-development-through-infrastructure-sharing/},
year = {2014},
date = {2014-01-01},
urldate = {2014-01-01},
journal = {International Journal of Business Data Communications and Networking, IGI Global},
volume = {10},
pages = {21-42},
abstract = {Broadband is a public utility with positive effects on competitiveness, employment and growth. Although evidence shows that broadband development is increasing, this increment is not homogeneous between urban and rural areas. The main factor is the high cost for deploying next generation networks in rural areas, and especially the cost linked to civil engineering works. In order to overcome the investment challenges arising in the context of broadband deployment, the European Commission made mandatory the sharing of existing telecommunication and non-telecommunication infrastructures and facilities. This manuscript proposes and presents a novel tool that enables the estimation of the expected savings from exploiting existing infrastructures when deploying a broadband network. This is followed by a number of general principles and recommendations that policy makers and national authorities could embrace to diminish deployment costs and promote broadband deployment.},
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Broadband is a public utility with positive effects on competitiveness, employment and growth. Although evidence shows that broadband development is increasing, this increment is not homogeneous between urban and rural areas. The main factor is the high cost for deploying next generation networks in rural areas, and especially the cost linked to civil engineering works. In order to overcome the investment challenges arising in the context of broadband deployment, the European Commission made mandatory the sharing of existing telecommunication and non-telecommunication infrastructures and facilities. This manuscript proposes and presents a novel tool that enables the estimation of the expected savings from exploiting existing infrastructures when deploying a broadband network. This is followed by a number of general principles and recommendations that policy makers and national authorities could embrace to diminish deployment costs and promote broadband deployment.
Bouras, Christos; Diles, Georgios; Kokkinos, Vasileios; Kontodimas, Konstantinos; Papazois, Andreas
A Simulation Framework for Evaluating Interference Mitigation Techniques in Heterogeneous Cellurar Environments Journal Article
In: Wireless Personal Communications, Springer Verlang, vol. 77, pp. 1213-1237, 2014.
Abstract | Links | BibTeX | Tags:
@article{3440,
title = {A Simulation Framework for Evaluating Interference Mitigation Techniques in Heterogeneous Cellurar Environments},
author = {Christos Bouras and Georgios Diles and Vasileios Kokkinos and Konstantinos Kontodimas and Andreas Papazois},
url = {https://telematics.upatras.gr/wpcfinal/},
year = {2014},
date = {2014-01-01},
urldate = {2014-01-01},
journal = {Wireless Personal Communications, Springer Verlang},
volume = {77},
pages = {1213-1237},
abstract = {Femtocells present an attractive solution for the improvement of a mobile network services providing better data rates and coverage. Since their deployment results to a heterogeneous network where two layers must utilize the available spectrum, issues of interference arise. A method to address this challenge, is investigating the locations of the newly installed FBS, and enforcing a power controlled transmission of all FBSs that achieves optimal and fair overall performance. Another option that becomes available in inter-cell interference cancellation (ICIC) macrocell environments, is utilizing the available spectrum to complete or partly avoid co-channel operation. In this work, we provide a simulation framework that allows the creation of custom, high configurable, user defined topologies of femtocells with power control and frequency allocation capabilities. It allows the investigation of the margin of improvement in interference when these methods are applied and may work as a decision tool for planning and evaluating heterogeneous networks. To showcase the frameworks
capabilities, we evaluate and study the behaviour of custom deployed femtocells/macrocells networks and examine the cross-tier interference issues. Facilitated by the framework, we enforce and evaluate each interference mitigation technique for different femtocells? deployment densities. Finally, we compare the results of each method in terms of total throughput, spectral efficiency and cell-edge users performance.},
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}
Femtocells present an attractive solution for the improvement of a mobile network services providing better data rates and coverage. Since their deployment results to a heterogeneous network where two layers must utilize the available spectrum, issues of interference arise. A method to address this challenge, is investigating the locations of the newly installed FBS, and enforcing a power controlled transmission of all FBSs that achieves optimal and fair overall performance. Another option that becomes available in inter-cell interference cancellation (ICIC) macrocell environments, is utilizing the available spectrum to complete or partly avoid co-channel operation. In this work, we provide a simulation framework that allows the creation of custom, high configurable, user defined topologies of femtocells with power control and frequency allocation capabilities. It allows the investigation of the margin of improvement in interference when these methods are applied and may work as a decision tool for planning and evaluating heterogeneous networks. To showcase the frameworks
capabilities, we evaluate and study the behaviour of custom deployed femtocells/macrocells networks and examine the cross-tier interference issues. Facilitated by the framework, we enforce and evaluate each interference mitigation technique for different femtocells? deployment densities. Finally, we compare the results of each method in terms of total throughput, spectral efficiency and cell-edge users performance.
capabilities, we evaluate and study the behaviour of custom deployed femtocells/macrocells networks and examine the cross-tier interference issues. Facilitated by the framework, we enforce and evaluate each interference mitigation technique for different femtocells? deployment densities. Finally, we compare the results of each method in terms of total throughput, spectral efficiency and cell-edge users performance.
Adam, George; Bouras, Christos; Kalligeros, Ioannis - Christos; Stamos, Kostas; Zaoudis, Giannis
Multi - domain Information Exchange in a Bandwidth on Demand Tool Journal Article
In: Journal of Networks, Academy Publishers, vol. 9, No. 5, pp. 1075-1085, 2014.
Abstract | Links | BibTeX | Tags:
@article{3442,
title = {Multi - domain Information Exchange in a Bandwidth on Demand Tool},
author = {George Adam and Christos Bouras and Ioannis - Christos Kalligeros and Kostas Stamos and Giannis Zaoudis},
url = {https://telematics.upatras.gr/397512508-27305-1-pb/},
year = {2014},
date = {2014-01-01},
urldate = {2014-01-01},
journal = {Journal of Networks, Academy Publishers},
volume = {9, No. 5},
pages = {1075-1085},
abstract = {In this paper we describe the multi-domain information exchange aspects of the AutoBAHN tool, which is used for implementing a Bandwidth on Demand service as part of the GEANT project. This project was driven by the increasing demand for reliable and guaranteed data transportation for scientific purposes. In order to implement the process of information exchange in a multidomain heterogeneous environment several design decisions have to take place, in order to balance and satisfy by the needs of information security, fast information dissemination, efficient request processing, reliability and obustness. The paper describes how AutoBAHN mplements a flexible AAI in a distributed environment, how it exchanges and updates information and how it handles incoming requests in an efficient and timely manner.The multi-domain aspect of this effort stems from the fact that the tool is used in the production environment of several cooperating National Research and Educational Networks (NRENs) across Europe. Each NREN may have different underlying technologies, different policies and different use cases, but they all have to coordinate through usage of the AutoBAHN tool in order to produce a multidomain service of circuit reservation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper we describe the multi-domain information exchange aspects of the AutoBAHN tool, which is used for implementing a Bandwidth on Demand service as part of the GEANT project. This project was driven by the increasing demand for reliable and guaranteed data transportation for scientific purposes. In order to implement the process of information exchange in a multidomain heterogeneous environment several design decisions have to take place, in order to balance and satisfy by the needs of information security, fast information dissemination, efficient request processing, reliability and obustness. The paper describes how AutoBAHN mplements a flexible AAI in a distributed environment, how it exchanges and updates information and how it handles incoming requests in an efficient and timely manner.The multi-domain aspect of this effort stems from the fact that the tool is used in the production environment of several cooperating National Research and Educational Networks (NRENs) across Europe. Each NREN may have different underlying technologies, different policies and different use cases, but they all have to coordinate through usage of the AutoBAHN tool in order to produce a multidomain service of circuit reservation.
Bilios, Dimitrios; Bouras, Christos; Diles, Georgios; Kokkinos, Vasileios; Papazois, Andreas; Tseliou, Georgia
A Simulation Framework for the Evaluation of Frequency Reuse in LTE - A Systems Journal Article
In: International Journal of Wireless Networks and Broadband Technologies, IGI Global, vol. 3, pp. 56-83, 2014.
Abstract | Links | BibTeX | Tags:
@article{3439,
title = {A Simulation Framework for the Evaluation of Frequency Reuse in LTE - A Systems},
author = {Dimitrios Bilios and Christos Bouras and Georgios Diles and Vasileios Kokkinos and Andreas Papazois and Georgia Tseliou},
url = {https://telematics.upatras.gr/a-simulation-framework-for-the-evaluation-of-frequency-reuse-in-lte-a-systems/},
year = {2014},
date = {2014-01-01},
urldate = {2014-01-01},
journal = {International Journal of Wireless Networks and Broadband Technologies, IGI Global},
volume = {3},
pages = {56-83},
abstract = {Long Term Evolution Advanced (LTE-A) technology is considered as the most possible candidate for next generation mobile communications. LTE-A networks offer high capacity and are specified and designed to accommodate small, high performance, power-efficient end-user devices. Similarly to its predecessor LTE, LTE-A incorporates inter-cell interference mitigation methods in order to mitigate interference and to enhance efficiency in bandwidth usage. These methods include power and frequency allocation schemes that allow neighbouring cells and femtocells in heterogeneous networks to co-ordinately share and reuse available spectral resources, in order to avoid performance degradation for interference suffering cell-edge users. In this paper, we study the LTE-A multi-cell systems? performance using a simulation framework, which integrates several frequency reuse techniques and provides a user-friendly graphical presentation of the evaluation results. The optimal Fractional Frequency Reuse (FFR) configuration for the user-defined network instance is also determined, based on overall performance and fairness index metrics. Finally, we examine FFR techniques in two-tier femtocell/macrocell environments and evaluate them based on the optimization of different metrics, depending on the network operator?s needs.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Long Term Evolution Advanced (LTE-A) technology is considered as the most possible candidate for next generation mobile communications. LTE-A networks offer high capacity and are specified and designed to accommodate small, high performance, power-efficient end-user devices. Similarly to its predecessor LTE, LTE-A incorporates inter-cell interference mitigation methods in order to mitigate interference and to enhance efficiency in bandwidth usage. These methods include power and frequency allocation schemes that allow neighbouring cells and femtocells in heterogeneous networks to co-ordinately share and reuse available spectral resources, in order to avoid performance degradation for interference suffering cell-edge users. In this paper, we study the LTE-A multi-cell systems? performance using a simulation framework, which integrates several frequency reuse techniques and provides a user-friendly graphical presentation of the evaluation results. The optimal Fractional Frequency Reuse (FFR) configuration for the user-defined network instance is also determined, based on overall performance and fairness index metrics. Finally, we examine FFR techniques in two-tier femtocell/macrocell environments and evaluate them based on the optimization of different metrics, depending on the network operator?s needs.
Bouras, Christos; Tsiatsos, Thrasivoulos; Triglianos, Vasileios
Implementing Advanced Characteristics of X3D Collaborative Virtual Environments for supporting e - Learning: The Case of EVE Platform Journal Article
In: International Journal of Distance Education Technologies, IDEA Group Publishing, vol. 12, pp. 13-37, 2014.
Abstract | Links | BibTeX | Tags:
@article{3111,
title = {Implementing Advanced Characteristics of X3D Collaborative Virtual Environments for supporting e - Learning: The Case of EVE Platform},
author = {Christos Bouras and Thrasivoulos Tsiatsos and Vasileios Triglianos},
url = {https://telematics.upatras.gr/5804jdet-bouras-triglianos-tsiatsos-f/},
year = {2014},
date = {2014-01-01},
urldate = {2014-01-01},
journal = {International Journal of Distance Education Technologies, IDEA Group Publishing},
volume = {12},
pages = {13-37},
abstract = {Three dimensional Collaborative Virtual Environments are a powerful form of collaborative telecommunication applications, enabling the users to share a common three-dimensional space and interact with each other as well as with the environment surrounding them, in order to collaboratively solve problems or aid learning processes. Such an environment is “EVE Training Area tool” which is supported by “EVE platform”. This tool is a three-dimensional space where participants, represented by three-dimensional humanoid avatars, can use a variety of e-collaboration tools. This paper presents advanced functionality that has been integrated on “EVE Training Area tool” in order to support: (a) multiple collaborative learning techniques (b) Spatial audio conferencing, which is targeted to support principle 3 (augmenting users representation and awareness). Furthermore the paper presents technological and implementation issues concerning the evolution of “EVE platform” in order to support this functionality.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Three dimensional Collaborative Virtual Environments are a powerful form of collaborative telecommunication applications, enabling the users to share a common three-dimensional space and interact with each other as well as with the environment surrounding them, in order to collaboratively solve problems or aid learning processes. Such an environment is “EVE Training Area tool” which is supported by “EVE platform”. This tool is a three-dimensional space where participants, represented by three-dimensional humanoid avatars, can use a variety of e-collaboration tools. This paper presents advanced functionality that has been integrated on “EVE Training Area tool” in order to support: (a) multiple collaborative learning techniques (b) Spatial audio conferencing, which is targeted to support principle 3 (augmenting users representation and awareness). Furthermore the paper presents technological and implementation issues concerning the evolution of “EVE platform” in order to support this functionality.
Adam, George; Bouras, Christos; Gkamas, Apostolos; Kapoulas, Vaggelis; Kioumourtzis, G
Cross Layer Design for Video Streaming in MANETs Journal Article
In: Journal of Networks, Academy Publishers, vol. 9, No. 2, pp. 328-338, 2014.
Abstract | Links | BibTeX | Tags:
@article{3441,
title = {Cross Layer Design for Video Streaming in MANETs},
author = {George Adam and Christos Bouras and Apostolos Gkamas and Vaggelis Kapoulas and G Kioumourtzis},
url = {https://telematics.upatras.gr/26fa4fa910299646670c90f124817d870a1e/},
year = {2014},
date = {2014-01-01},
urldate = {2014-01-01},
journal = {Journal of Networks, Academy Publishers},
volume = {9, No. 2},
pages = {328-338},
abstract = {Mobile Ad hoc NETworks (MANETs) are becoming more essential to wireless communications due to growing popularity of mobile devices. However, MANETs do not seem to effectively support multimedia applications and especially video transmission. In this work, we propose a cross-layer design that aims to improve the performance of video transmission using TCP Friendly Rate Control (TFRC). Our design provides priority to video packets and exploits information from the MAC layer in order to improve TFRCs performance. The proposed cross-layer design utilizes SNR measurements along the routing path, in order to make the route reconstruction procedure more efficient. Simulation results show that both the use of traffic classification and the SNR utilization lead to important improvements in terms of end-to-end Quality of Service (QoS).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Mobile Ad hoc NETworks (MANETs) are becoming more essential to wireless communications due to growing popularity of mobile devices. However, MANETs do not seem to effectively support multimedia applications and especially video transmission. In this work, we propose a cross-layer design that aims to improve the performance of video transmission using TCP Friendly Rate Control (TFRC). Our design provides priority to video packets and exploits information from the MAC layer in order to improve TFRCs performance. The proposed cross-layer design utilizes SNR measurements along the routing path, in order to make the route reconstruction procedure more efficient. Simulation results show that both the use of traffic classification and the SNR utilization lead to important improvements in terms of end-to-end Quality of Service (QoS).
Bouras, Christos; Filopoulos, Anestis; Kokkinos, Vasileios; Michalopoulos, Sotiris; Papadopoulos, Dimitris; Tseliou, Georgia
Policy recommendations for public administrators on free and open source software usage Journal Article
In: Telematics and Informatics, Elsevier Science, vol. 31, 2014.
Abstract | Links | BibTeX | Tags:
@article{3443,
title = {Policy recommendations for public administrators on free and open source software usage},
author = {Christos Bouras and Anestis Filopoulos and Vasileios Kokkinos and Sotiris Michalopoulos and Dimitris Papadopoulos and Georgia Tseliou},
url = {https://telematics.upatras.gr/30291-s2-0-s0736585313000361-main/},
year = {2014},
date = {2014-01-01},
urldate = {2014-01-01},
journal = {Telematics and Informatics, Elsevier Science},
volume = {31},
abstract = {Free and open source software, holding a strategic position in knowledge economy, reaffirms the critical role of governments and regional authorities in establishing strategies for integrating effective and sustainable Information Technology solutions in the public sector towards economic growth and social welfare. Moreover, public services, organizations and territorial administrations collectively represent a major software user with great impact on the software market. In this sense, software selection in the public sector is a highly political and strategic process; various collateral implications and policy aspects should be considered in order to reach the best possible decisions. Within this context, this manuscript provides policy recommendations on issues and challenges pertaining to the use of free and open source software by European public administrations. The recommended policy actions are mainly based on review of the current policy framework. The main goal of this manuscript is to contribute in providing policy orientations and proposing actions that can help governments, public administrations and European institutions fully harvest the benefits of open source.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Free and open source software, holding a strategic position in knowledge economy, reaffirms the critical role of governments and regional authorities in establishing strategies for integrating effective and sustainable Information Technology solutions in the public sector towards economic growth and social welfare. Moreover, public services, organizations and territorial administrations collectively represent a major software user with great impact on the software market. In this sense, software selection in the public sector is a highly political and strategic process; various collateral implications and policy aspects should be considered in order to reach the best possible decisions. Within this context, this manuscript provides policy recommendations on issues and challenges pertaining to the use of free and open source software by European public administrations. The recommended policy actions are mainly based on review of the current policy framework. The main goal of this manuscript is to contribute in providing policy orientations and proposing actions that can help governments, public administrations and European institutions fully harvest the benefits of open source.
Bouras, Christos; Papazois, Andreas; Kokkinos, Vasileios; Kanakis, Nikos
Embracing RaptorQ FEC in 3GPP multicast services Journal Article
In: Wireless Networks, Springer Verlang, pp. 1023-1035, vol. 19, pp. 1023-1035, 2013.
Abstract | Links | BibTeX | Tags: FEC, MBMS
@article{3119,
title = {Embracing RaptorQ FEC in 3GPP multicast services},
author = {Christos Bouras and Andreas Papazois and Vasileios Kokkinos and Nikos Kanakis},
url = {https://telematics.upatras.gr/331510-1007_s11276-012-0515-3/},
year = {2013},
date = {2013-01-01},
urldate = {2013-01-01},
journal = {Wireless Networks, Springer Verlang, pp. 1023-1035},
volume = {19},
pages = {1023-1035},
abstract = {Multimedia Broadcast/Multicast Services (MBMS) have been introduced by Third Generation Partnership Project (3GPP) aiming to efficiently deliver data to mobile users in a one-to-many way. In order to provide reliable multicast transmission, 3GPP recommends exclusively for MBMS the use of a Forward Error Correction (FEC) mechanism on the application layer. Raptor codes are standardized as the Application Layer FEC (AL-FEC) scheme over 3GPP MBMS. However, the 3GPP standardized systematic fountain Raptor code is nowadays considered obsolete, since a new variation of the Raptor codes has emerged. This enhanced AL-FEC scheme, named RaptorQ, promises higher protection efficiency and superior flexibility on the provision of demanding mobile multicast services. In this work, we provide an extensive performance evaluation presenting at first a theoretical performance comparison of the newly introduced RaptorQ FEC scheme with its predecessor Raptor code, examining the enhancements that RaptorQ introduces on the AL-FEC protection robustness. Thereafter, to verify the enhanced performance of RaptorQ, we present several simulation results considering the modeling of the AL-FEC protection over multicast services for next generation mobile networks, utilizing the ns-3 simulation environment. Investigating several mobile system parameters in conjunction with FEC encoding parameters, we provide valuable results regarding the impacts of the examined AL-FEC schemes application on the multicast services performance.},
keywords = {FEC, MBMS},
pubstate = {published},
tppubtype = {article}
}
Multimedia Broadcast/Multicast Services (MBMS) have been introduced by Third Generation Partnership Project (3GPP) aiming to efficiently deliver data to mobile users in a one-to-many way. In order to provide reliable multicast transmission, 3GPP recommends exclusively for MBMS the use of a Forward Error Correction (FEC) mechanism on the application layer. Raptor codes are standardized as the Application Layer FEC (AL-FEC) scheme over 3GPP MBMS. However, the 3GPP standardized systematic fountain Raptor code is nowadays considered obsolete, since a new variation of the Raptor codes has emerged. This enhanced AL-FEC scheme, named RaptorQ, promises higher protection efficiency and superior flexibility on the provision of demanding mobile multicast services. In this work, we provide an extensive performance evaluation presenting at first a theoretical performance comparison of the newly introduced RaptorQ FEC scheme with its predecessor Raptor code, examining the enhancements that RaptorQ introduces on the AL-FEC protection robustness. Thereafter, to verify the enhanced performance of RaptorQ, we present several simulation results considering the modeling of the AL-FEC protection over multicast services for next generation mobile networks, utilizing the ns-3 simulation environment. Investigating several mobile system parameters in conjunction with FEC encoding parameters, we provide valuable results regarding the impacts of the examined AL-FEC schemes application on the multicast services performance.
Bouras, Christos; Alexiou, Antonios; Papazois, Andreas; Kokkinos, Vasileios; Tsichritzis, George
Modulation and coding scheme selection in multimedia broadcast over a single frequency network-enabled long-term evolution networks Journal Article
In: International Journal of Communication Systems, Wiley InterScience, pp. 1603-1619, vol. 25, pp. 1603-1619, 2013.
Abstract | Links | BibTeX | Tags: LTE, MBSFN, MCS
@article{3105,
title = {Modulation and coding scheme selection in multimedia broadcast over a single frequency network-enabled long-term evolution networks},
author = {Christos Bouras and Antonios Alexiou and Andreas Papazois and Vasileios Kokkinos and George Tsichritzis},
url = {https://telematics.upatras.gr/1745ijcs2012dac1326/},
year = {2013},
date = {2013-01-01},
urldate = {2013-01-01},
journal = {International Journal of Communication Systems, Wiley InterScience, pp. 1603-1619},
volume = {25},
pages = {1603-1619},
abstract = {Long term evolution constitutes the next generation cellular network beyond 3G that is designed to support the explosion in demand for bandwidth-hungry multimedia services in wireless networks by providing an extremely high performance radio access technology. To support multimedia broadcast/multicast services (MBMS), long term evolution offers the functionality to transmit MBMS over a single frequency network, where a time-synchronized common waveform is transmitted from multiple cells for a given duration. This enables over-the-air combining, thus significantly improving the spectral efficiency (SE) compared with conventional MBMS operations. In MBMS over a single frequency network transmissions, the achieved SE is mainly determined by the modulation and coding scheme selected. This study proposes and evaluates four approaches for the selection of the modulation and coding scheme. Each approach corresponds to different users? distribution and multimedia traffic conditions. On the basis of SE measurements, we determine the approach that either maximizes or achieves a target SE for the corresponding users distribution and traffic conditions. Copyright © 2011 John Wiley & Sons, Ltd.},
keywords = {LTE, MBSFN, MCS},
pubstate = {published},
tppubtype = {article}
}
Long term evolution constitutes the next generation cellular network beyond 3G that is designed to support the explosion in demand for bandwidth-hungry multimedia services in wireless networks by providing an extremely high performance radio access technology. To support multimedia broadcast/multicast services (MBMS), long term evolution offers the functionality to transmit MBMS over a single frequency network, where a time-synchronized common waveform is transmitted from multiple cells for a given duration. This enables over-the-air combining, thus significantly improving the spectral efficiency (SE) compared with conventional MBMS operations. In MBMS over a single frequency network transmissions, the achieved SE is mainly determined by the modulation and coding scheme selected. This study proposes and evaluates four approaches for the selection of the modulation and coding scheme. Each approach corresponds to different users? distribution and multimedia traffic conditions. On the basis of SE measurements, we determine the approach that either maximizes or achieves a target SE for the corresponding users distribution and traffic conditions. Copyright © 2011 John Wiley & Sons, Ltd.
Bouras, Christos; Papazois, Andreas; Kokkinos, Vasileios; Tseliou, Georgia; Bilios, Dimitrios
Selecting the Optimal Fractional Frequency Reuse Scheme in Long Term Evolution Networks Journal Article
In: Wireless Personal Communications, Springer Verlang, pp. 2693-2712, vol. 71, pp. 2693-2712, 2013.
Abstract | Links | BibTeX | Tags: FFR
@article{3121,
title = {Selecting the Optimal Fractional Frequency Reuse Scheme in Long Term Evolution Networks},
author = {Christos Bouras and Andreas Papazois and Vasileios Kokkinos and Georgia Tseliou and Dimitrios Bilios},
url = {https://telematics.upatras.gr/2659wpc10-1007_s11277-012-0965-z/},
year = {2013},
date = {2013-01-01},
urldate = {2013-01-01},
journal = {Wireless Personal Communications, Springer Verlang, pp. 2693-2712},
volume = {71},
pages = {2693-2712},
abstract = {Long Term Evolution (LTE) networks offer high capacity and are specified and designed to accommodate small, high performance, power-efficient end-user devices. One limiting factor that influences LTE performance is the interference from neighbouring cells, the so called Inter-Cell Interference (ICI). The investigation of ICI mitigation techniques has become a key focus area in achieving dense spectrum reuse in next generation cellular systems. Fractional Frequency Reuse (FFR) has been proposed as a technique to overcome this problem, since it can efficiently utilize the available frequency spectrum. This manuscript proposes a dynamic mechanism that selects the optimal FFR scheme based on a custom metric, which is called user satisfaction. In detail, the proposed mechanism divides the cell into two regions, the inner and outer region, and selects the optimal size as well as the optimal frequency allocation between these regions with main target to maximize the user satisfaction metric. The proposed mechanism is evaluated through several simulation scenarios that incorporate users? mobility and its selected FFR scheme is compared with other frequency reuse schemes in order to highlight its performance.},
keywords = {FFR},
pubstate = {published},
tppubtype = {article}
}
Long Term Evolution (LTE) networks offer high capacity and are specified and designed to accommodate small, high performance, power-efficient end-user devices. One limiting factor that influences LTE performance is the interference from neighbouring cells, the so called Inter-Cell Interference (ICI). The investigation of ICI mitigation techniques has become a key focus area in achieving dense spectrum reuse in next generation cellular systems. Fractional Frequency Reuse (FFR) has been proposed as a technique to overcome this problem, since it can efficiently utilize the available frequency spectrum. This manuscript proposes a dynamic mechanism that selects the optimal FFR scheme based on a custom metric, which is called user satisfaction. In detail, the proposed mechanism divides the cell into two regions, the inner and outer region, and selects the optimal size as well as the optimal frequency allocation between these regions with main target to maximize the user satisfaction metric. The proposed mechanism is evaluated through several simulation scenarios that incorporate users? mobility and its selected FFR scheme is compared with other frequency reuse schemes in order to highlight its performance.
Bouras, Christos; Papazois, Andreas; Kokkinos, Vasileios; Kanakis, Nikos
Application Layer Forward Error Correction for Multicast Streaming over LTE Networks Journal Article
In: International Journal of Communication Systems, Wiley InterScience, pp. 1459-1574, vol. 26, pp. 1459-1574, 2013.
Abstract | Links | BibTeX | Tags: FEC, LTE, MBMS
@article{3113,
title = {Application Layer Forward Error Correction for Multicast Streaming over LTE Networks},
author = {Christos Bouras and Andreas Papazois and Vasileios Kokkinos and Nikos Kanakis},
url = {https://telematics.upatras.gr/3846dac2321/},
year = {2013},
date = {2013-01-01},
urldate = {2013-01-01},
journal = {International Journal of Communication Systems, Wiley InterScience, pp. 1459-1574},
volume = {26},
pages = {1459-1574},
abstract = {The next step beyond third generation (3G) mobile networks is the Third Generation Partnership Project (3GPP) standard, named Long Term Evolution (LTE). A key feature of LTE is the enhancement of Multimedia Broadcast/Multicast Services (MBMS), where the same content is transmitted to multiple users located in a specific service area. To support efficient download and streaming delivery, 3GPP included an application layer Forward Error Correction (AL-FEC) technique based on the systematic fountain Raptor code, in the MBMS standard. In order to achieve protection against packet losses, Raptor codes introduce redundant packets to the transmission, i.e., the FEC overhead. In this work, we investigate the application of AL-FEC over MBMS streaming services. We consider the benefits of AL-FEC for a continuous multimedia stream transmission to multiple users and we examine how the amount of FEC redundancy can be adjusted under different packet loss conditions. For this purpose, we present a variety of realistic simulation scenarios for the application of AL-FEC and furthermore we provide an in-depth analysis of Raptor codes performance introducing valuable suggestions to achieve efficient use of Raptor codes.},
keywords = {FEC, LTE, MBMS},
pubstate = {published},
tppubtype = {article}
}
The next step beyond third generation (3G) mobile networks is the Third Generation Partnership Project (3GPP) standard, named Long Term Evolution (LTE). A key feature of LTE is the enhancement of Multimedia Broadcast/Multicast Services (MBMS), where the same content is transmitted to multiple users located in a specific service area. To support efficient download and streaming delivery, 3GPP included an application layer Forward Error Correction (AL-FEC) technique based on the systematic fountain Raptor code, in the MBMS standard. In order to achieve protection against packet losses, Raptor codes introduce redundant packets to the transmission, i.e., the FEC overhead. In this work, we investigate the application of AL-FEC over MBMS streaming services. We consider the benefits of AL-FEC for a continuous multimedia stream transmission to multiple users and we examine how the amount of FEC redundancy can be adjusted under different packet loss conditions. For this purpose, we present a variety of realistic simulation scenarios for the application of AL-FEC and furthermore we provide an in-depth analysis of Raptor codes performance introducing valuable suggestions to achieve efficient use of Raptor codes.