01869nas a2200169   4500008004100000245006000041210006000101260005000161300001500211520125500226653002301481653000901504100002101513700002201534700002201556856012101578       2009                        eng d00aCongestion Control for Multicast Transmission over UMTS0 aCongestion Control for Multicast Transmission over UMTS  bAuerbach Publications, Taylor & Francis Group  a 291 - 3123 a<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>
10aCongestion Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas  uhttp://telematics.upatras.gr/telematics/publications/congestion-control-multicast-transmission-over-umts?language=el01464nas a2200169   4500008004100000245005300041210005100094300001500145520091900160653002301079653000901102653000901111100002101120700002201141700002201163856010901185       2009                        eng d00aA Study of Multicast Congestion Control for UMTS0 aStudy of Multicast Congestion Control for UMTS  a 739 - 7543 aIn 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.10aCongestion Control10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas  uhttp://telematics.upatras.gr/telematics/publications/study-multicast-congestion-control-umts?language=el01475nas a2200157   4500008004100000245008000041210006900121300001300190520087200203653002301075653000901098100002101107700002201128700002601150856014101176       2007                        eng d00aAdaptive and Reliable Video Transmission over UMTS for Enhanced Performance0 aAdaptive and Reliable Video Transmission over UMTS for Enhanced   a 65 - 813 aThis 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.10aCongestion Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aAntonellis, Dimitrios  uhttp://telematics.upatras.gr/telematics/publications/adaptive-and-reliable-video-transmission-over-umts-enhanced-performance?language=el01355nas a2200169   4500008004100000245005200041210004500093260001900138300001300157520081400170653002300984653000901007100002101016700002201037700002201059856010401081       2007                        eng d00aOn the Applicability of pgmcc to UMTS Multicast0 aApplicability of pgmcc to UMTS Multicast  c5 - 7 December  a 67 - 723 aIn 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 analysis10aCongestion Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas  uhttp://telematics.upatras.gr/telematics/publications/applicability-pgmcc-umts-multicast?language=el01485nas a2200157   4500008004100000245005900041210005900100300001700159520093300176653002301109653000901132100002101141700002201162700002301184856012001207       2007                        eng d00aScalable Rate Control for Video Transmission over UMTS0 aScalable Rate Control for Video Transmission over UMTS  a 1315 - 11313 aThis 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 performance 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.10aCongestion Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aIgglesis, Vaggelis  uhttp://telematics.upatras.gr/telematics/publications/scalable-rate-control-video-transmission-over-umts?language=el01542nas a2200169   4500008004100000245008100041210006900122260001800191300001500209520090500224653002301129653000901152100002101161700002201182700002601204856014201230       2006                        eng d00aEquation Based Congestion Control for Video Transmission over WCDMA Networks0 aEquation Based Congestion Control for Video Transmission over WC  c18 - 20 April  a 445 - 4503 a   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.
10aCongestion Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aAntonellis, Dimitrios  uhttp://telematics.upatras.gr/telematics/publications/equation-based-congestion-control-video-transmission-over-wcdma-networks?language=el01348nas a2200169   4500008004100000245008600041210006900127260002200196300001500218520071500233653002300948653000900971653000900980100002100989700002201010856014601032       2005                        eng d00aRate and Loss Control for Video transmission over UMTS using Real -Time Protocols0 aRate and Loss Control for Video transmission over UMTS using Rea  c27 - 29 September  a 333 - 3363 aUMTS 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.10aCongestion Control10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios  uhttp://telematics.upatras.gr/telematics/publications/rate-and-loss-control-video-transmission-over-umts-using-real-time-protocols?language=el