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; Alexiou, Antonios; Papazois, Andreas
A Study of Multicast Congestion Control for UMTS Journal Article
In: International Journal of Communication Systems, Wiley InterScience, pp. 739 - 754, 2009.
Abstract | Links | BibTeX | Tags: Congestion Control, MBMS, UMTS
@article{3087,
title = {A Study of Multicast Congestion Control for UMTS},
author = {Christos Bouras and Antonios Alexiou and Andreas Papazois},
url = {https://telematics.upatras.gr/9464ijcs/},
year = {2009},
date = {2009-01-01},
urldate = {2009-01-01},
journal = {International Journal of Communication Systems, Wiley InterScience},
pages = {739 - 754},
abstract = {In this paper, we study the applicability of multicast congestion control over universal mobile telecommunications system (UMTS) networks. We analyze two well-known multicast congestion control schemes for fixed networks, namely TCP-friendly multicast congestion control and pragmatic general multicast congestion control. We investigate their behavior when they are employed in UMTS networks and we analyze the problems arose when these mechanisms are applied over the wireless links of the UMTS terrestrial radio-access network. Additionally, we propose necessary improvements to these legacy schemes and explain the necessity of these modifications. The proposed schemes are implemented in the ns-2 network simulator and are evaluated under various network conditions and topologies. Finally, we measure the performance of the proposed modified schemes and compare them with the corresponding legacy mechanisms.},
keywords = {Congestion Control, MBMS, UMTS},
pubstate = {published},
tppubtype = {article}
}
In this paper, we study the applicability of multicast congestion control over universal mobile telecommunications system (UMTS) networks. We analyze two well-known multicast congestion control schemes for fixed networks, namely TCP-friendly multicast congestion control and pragmatic general multicast congestion control. We investigate their behavior when they are employed in UMTS networks and we analyze the problems arose when these mechanisms are applied over the wireless links of the UMTS terrestrial radio-access network. Additionally, we propose necessary improvements to these legacy schemes and explain the necessity of these modifications. The proposed schemes are implemented in the ns-2 network simulator and are evaluated under various network conditions and topologies. Finally, we measure the performance of the proposed modified schemes and compare them with the corresponding legacy mechanisms.
Bouras, Christos; Alexiou, Antonios; Antonellis, Dimitrios
Adaptive and Reliable Video Transmission over UMTS for Enhanced Performance Journal Article
In: International Journal of Communication Systems, Wiley InterScience Vol. 20, Issue 1, pp. 65 - 81, 2007.
Abstract | Links | BibTeX | Tags: Congestion Control, UMTS
@article{3070,
title = {Adaptive and Reliable Video Transmission over UMTS for Enhanced Performance},
author = {Christos Bouras and Antonios Alexiou and Dimitrios Antonellis},
url = {https://telematics.upatras.gr/4935ijcs1/},
year = {2007},
date = {2007-01-01},
urldate = {2007-01-01},
journal = {International Journal of Communication Systems, Wiley InterScience Vol. 20, Issue 1},
pages = {65 - 81},
abstract = {This paper proposes a mechanism for the congestion control for video transmission over universal mobile telecommunications system (UMTS). Our scheme is applied when the mobile user experiences real-time multimedia content and adopts the theory of a widely accepted rate control method in wired networks, namely equation-based rate control. In this approach, the transmission rate of the multimedia data is determined as a function of the packet loss rate, the round trip time and the packet size and the server explicitly adjusts its sending rate as a function of these parameters. Furthermore, we examine the performance of the UMTS for real-time video transmission using real-time protocols. Through a number of experiments, we measure performance parameters such as end-to-end delay, delay in radio access network, delay jitter and throughput in the wireless link.},
keywords = {Congestion Control, UMTS},
pubstate = {published},
tppubtype = {article}
}
This paper proposes a mechanism for the congestion control for video transmission over universal mobile telecommunications system (UMTS). Our scheme is applied when the mobile user experiences real-time multimedia content and adopts the theory of a widely accepted rate control method in wired networks, namely equation-based rate control. In this approach, the transmission rate of the multimedia data is determined as a function of the packet loss rate, the round trip time and the packet size and the server explicitly adjusts its sending rate as a function of these parameters. Furthermore, we examine the performance of the UMTS for real-time video transmission using real-time protocols. Through a number of experiments, we measure performance parameters such as end-to-end delay, delay in radio access network, delay jitter and throughput in the wireless link.
Bouras, Christos; Alexiou, Antonios; Igglesis, Vaggelis
Scalable Rate Control for Video Transmission over UMTS Journal Article
In: International Journal of Communication Systems, Wiley InterScience, Vol. 20, Issue 12, pp. 1315 - 1131, 2007.
Abstract | Links | BibTeX | Tags: Congestion Control, UMTS
@article{3072,
title = {Scalable Rate Control for Video Transmission over UMTS},
author = {Christos Bouras and Antonios Alexiou and Vaggelis Igglesis},
url = {https://telematics.upatras.gr/2309fulltext/},
year = {2007},
date = {2007-01-01},
urldate = {2007-01-01},
journal = {International Journal of Communication Systems, Wiley InterScience, Vol. 20, Issue 12},
pages = {1315 - 1131},
abstract = {This paper proposes a mechanism for the congestion control for video transmission over Universal Mobile Telecommunications System (UMTS). Our scheme is applied when the mobile user experiences real time multimedia content and adopts the theory of a widely accepted rate control method in wired networks, namely equation-based rate control. In this approach, the transmission rate of the multimedia data is determined as a function of the packet loss rate, the round trip time and the packet size and the server explicitly adjusts its sending rate as a function of these parameters. Through a number of simulations and experiments we validate the correctness and measure the erformance and efficiency of the mechanism. A first level of evaluation is carried out using the ns-2 simulator. A second level then validates the proposed mechanism in real world traffic scenarios by performing experiments in a commercial UMTS network.},
keywords = {Congestion Control, UMTS},
pubstate = {published},
tppubtype = {article}
}
This paper proposes a mechanism for the congestion control for video transmission over Universal Mobile Telecommunications System (UMTS). Our scheme is applied when the mobile user experiences real time multimedia content and adopts the theory of a widely accepted rate control method in wired networks, namely equation-based rate control. In this approach, the transmission rate of the multimedia data is determined as a function of the packet loss rate, the round trip time and the packet size and the server explicitly adjusts its sending rate as a function of these parameters. Through a number of simulations and experiments we validate the correctness and measure the erformance and efficiency of the mechanism. A first level of evaluation is carried out using the ns-2 simulator. A second level then validates the proposed mechanism in real world traffic scenarios by performing experiments in a commercial UMTS network.
Book Chapters
Bouras, Christos; Alexiou, Antonios; Papazois, Andreas
Congestion Control for Multicast Transmission over UMTS Book Chapter
In: Wireless Quality of Service: Techniques, Standards and Applications, Chapter 10, pp. 291 - 312, Auerbach Publications, Taylor & Francis Group, 2009.
Abstract | Links | BibTeX | Tags: Congestion Control, UMTS
@inbook{3129,
title = {Congestion Control for Multicast Transmission over UMTS},
author = {Christos Bouras and Antonios Alexiou and Andreas Papazois},
url = {https://telematics.upatras.gr/wp-content/uploads/2024/01/9346final_chapter_with_pics.pdf},
year = {2009},
date = {2009-01-01},
urldate = {2009-01-01},
booktitle = {Wireless Quality of Service: Techniques, Standards and Applications},
pages = {291 - 312},
publisher = {Auerbach Publications, Taylor & Francis Group},
chapter = {10},
organization = {Auerbach Publications, Taylor & Francis Group},
abstract = {<p>In this chapter, we present a novel mechanism for the multicast congestion control over Universal Mobile Telecommunications System (UMTS) networks. The proposed mechanism is based on the well known TCP-Friendly Multicast Congestion Control (TFMCC) scheme. TFMCC is an equation-based multicast congestion control mechanism intended to scale to groups of several thousand receivers. It is based on the concept of Current Limiting Receiver (CLR). The CLR is the receiver that the sender believes currently has the lowest expected throughput of the multicast group. The key challenge in the design of the new scheme lies in extending TFMCC in order to support the UMTS Terrestrial Radio-Access Network (UTRAN). Our major contribution is that the TFMCC mechanism was improved in order to cope with the packet losses caused by either the temporary or the permanent degradation of the wireless channel. One of the major advantages of the proposed scheme is that it introduces minor modifications in the UMTS nodes with respect to the computing power of the mobile terminals. Finally, we implement our approach in the ns-2 network simulator and we evaluate it under various conditions. The simulation results are presented along with their analysis.</p>},
keywords = {Congestion Control, UMTS},
pubstate = {published},
tppubtype = {inbook}
}
<p>In this chapter, we present a novel mechanism for the multicast congestion control over Universal Mobile Telecommunications System (UMTS) networks. The proposed mechanism is based on the well known TCP-Friendly Multicast Congestion Control (TFMCC) scheme. TFMCC is an equation-based multicast congestion control mechanism intended to scale to groups of several thousand receivers. It is based on the concept of Current Limiting Receiver (CLR). The CLR is the receiver that the sender believes currently has the lowest expected throughput of the multicast group. The key challenge in the design of the new scheme lies in extending TFMCC in order to support the UMTS Terrestrial Radio-Access Network (UTRAN). Our major contribution is that the TFMCC mechanism was improved in order to cope with the packet losses caused by either the temporary or the permanent degradation of the wireless channel. One of the major advantages of the proposed scheme is that it introduces minor modifications in the UMTS nodes with respect to the computing power of the mobile terminals. Finally, we implement our approach in the ns-2 network simulator and we evaluate it under various conditions. The simulation results are presented along with their analysis.</p>
Conferences
Bouras, Christos; Alexiou, Antonios; Papazois, Andreas
On the Applicability of pgmcc to UMTS Multicast Conference
2007 International Conference on Late Advances in Networks (ICLAN-2007), Paris, France, pp. 67-72, 2007.
Abstract | Links | BibTeX | Tags: Congestion Control, UMTS
@conference{2914,
title = {On the Applicability of pgmcc to UMTS Multicast},
author = {Christos Bouras and Antonios Alexiou and Andreas Papazois},
url = {https://telematics.upatras.gr/1423iclan07_cr/},
year = {2007},
date = {2007-12-01},
urldate = {2007-12-01},
booktitle = {2007 International Conference on Late Advances in Networks (ICLAN-2007), Paris, France, pp. 67-72},
pages = {67 - 72},
abstract = {In this paper, we investigate the applicability of the Pragmatic General Multicast Congestion Control (pgmcc) scheme to the multicast data delivery over Universal Mobile Telecommunications System (UMTS) networks. We show that the pgmcc scheme cannot support the degradation of the radio channels in the UMTS Terrestrial Radio-Access Network (UTRAN). Our major contribution is that the legacy scheme is modified in order to cope with the packet losses caused by either the temporary or the permanent degradation of the radio channel. The proposed scheme introduces minor modifications in the UMTS nodes and respects the limited computing power of the mobile equipment. Finally, we simulate our approach and we evaluate it under various conditions. The simulation results are presented along with their analysis},
keywords = {Congestion Control, UMTS},
pubstate = {published},
tppubtype = {conference}
}
In this paper, we investigate the applicability of the Pragmatic General Multicast Congestion Control (pgmcc) scheme to the multicast data delivery over Universal Mobile Telecommunications System (UMTS) networks. We show that the pgmcc scheme cannot support the degradation of the radio channels in the UMTS Terrestrial Radio-Access Network (UTRAN). Our major contribution is that the legacy scheme is modified in order to cope with the packet losses caused by either the temporary or the permanent degradation of the radio channel. The proposed scheme introduces minor modifications in the UMTS nodes and respects the limited computing power of the mobile equipment. Finally, we simulate our approach and we evaluate it under various conditions. The simulation results are presented along with their analysis
Bouras, Christos; Alexiou, Antonios; Antonellis, Dimitrios
Equation Based Congestion Control for Video Transmission over WCDMA Networks Conference
The IEEE 20th International Conference on Advanced Information Networking and Applications, Vienna, Austria, pp. 445-450, 2006.
Abstract | Links | BibTeX | Tags: Congestion Control, UMTS
@conference{2873,
title = {Equation Based Congestion Control for Video Transmission over WCDMA Networks},
author = {Christos Bouras and Antonios Alexiou and Dimitrios Antonellis},
url = {https://telematics.upatras.gr/3552aina_2006_antonellis/},
year = {2006},
date = {2006-04-01},
urldate = {2006-04-01},
booktitle = {The IEEE 20th International Conference on Advanced Information Networking and Applications, Vienna, Austria, pp. 445-450},
pages = {445 - 450},
abstract = {The scheme of real time streaming video is one of the newcomers in wireless data communication, raising a number of new requirements in both telecommunication and data communication systems. This scheme is applied when the user experiences real time multimedia content. Rate control is an important issue in video streaming applications for both wired and wireless networks. A widely accepted rate control method in wired networks is equation based rate control. In this work, we focus on a mechanism for equation based congestion control for video transmission over WCDMA networks. With our mechanism, the sender explicitly adjusts its sending rate as a function of the measured rate of loss events, the round trip time and the packet size. Furthermore, we examine the performance of UMTS air interface for real time video transmission using real time protocols, through a number of experiments.},
keywords = {Congestion Control, UMTS},
pubstate = {published},
tppubtype = {conference}
}
The scheme of real time streaming video is one of the newcomers in wireless data communication, raising a number of new requirements in both telecommunication and data communication systems. This scheme is applied when the user experiences real time multimedia content. Rate control is an important issue in video streaming applications for both wired and wireless networks. A widely accepted rate control method in wired networks is equation based rate control. In this work, we focus on a mechanism for equation based congestion control for video transmission over WCDMA networks. With our mechanism, the sender explicitly adjusts its sending rate as a function of the measured rate of loss events, the round trip time and the packet size. Furthermore, we examine the performance of UMTS air interface for real time video transmission using real time protocols, through a number of experiments.
Bouras, Christos; Alexiou, Antonios
Rate and Loss Control for Video transmission over UMTS using Real -Time Protocols Conference
13th Annual Meeting of the IEEE/ACM International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS 2005), Atlanta, Georgia, USA, pp. 333-336, 2005.
Abstract | Links | BibTeX | Tags: Congestion Control, MBMS, UMTS
@conference{2702,
title = {Rate and Loss Control for Video transmission over UMTS using Real -Time Protocols},
author = {Christos Bouras and Antonios Alexiou},
url = {https://telematics.upatras.gr/18771164/},
year = {2005},
date = {2005-09-01},
urldate = {2005-09-01},
booktitle = {13th Annual Meeting of the IEEE/ACM International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS 2005), Atlanta, Georgia, USA, pp. 333-336},
pages = {333 - 336},
abstract = {UMTS is evolving toward a future wireless all-IP network. In this paper we present how it supports real-time IP multimedia services, as these services are expected to drive the adoption of wireless all-IP networks. The scheme of real time streaming video is one of the newcomers in wireless data communication and in particular in UMTS, raising a number of novel requirements in both telecommunication and data communication systems. This scheme applies when the mobile user is experiencing real time video content. In this work we focus on the design and implementation of a rate and loss control mechanism for monitoring the UMTS network state and estimating the appropriate rate of the streaming video data.},
keywords = {Congestion Control, MBMS, UMTS},
pubstate = {published},
tppubtype = {conference}
}
UMTS is evolving toward a future wireless all-IP network. In this paper we present how it supports real-time IP multimedia services, as these services are expected to drive the adoption of wireless all-IP networks. The scheme of real time streaming video is one of the newcomers in wireless data communication and in particular in UMTS, raising a number of novel requirements in both telecommunication and data communication systems. This scheme applies when the mobile user is experiencing real time video content. In this work we focus on the design and implementation of a rate and loss control mechanism for monitoring the UMTS network state and estimating the appropriate rate of the streaming video data.