01909nas a2200193 4500008004100000245008900041210006900130300001400199490000700213520123400220653000801454653000801462653000901470100002101479700002201500700002401522700001901546856015001565 2013 eng d00aApplication Layer Forward Error Correction for Multicast Streaming over LTE Networks0 aApplication Layer Forward Error Correction for Multicast Streami a1459-15740 v263 a

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.

10aFEC10aLTE10aMBMS1 aBouras, Christos1 aPapazois, Andreas1 aKokkinos, Vasileios1 aKanakis, Nikos uhttp://telematics.upatras.gr/telematics/publications/application-layer-forward-error-correction-multicast-streaming-over-lte-networks?language=el02103nas a2200181 4500008004100000245005300041210005300094300001400147490000700161520153500168653000801703653000901711100002101720700002201741700002401763700001901787856011501806 2013 eng d00aEmbracing RaptorQ FEC in 3GPP multicast services0 aEmbracing RaptorQ FEC in 3GPP multicast services a1023-10350 v193 a

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.

10aFEC10aMBMS1 aBouras, Christos1 aPapazois, Andreas1 aKokkinos, Vasileios1 aKanakis, Nikos uhttp://telematics.upatras.gr/telematics/publications/embracing-raptorq-fec-3gpp-multicast-services?language=el01824nas a2200193 4500008004100000245005900041210005900100260001300159300001000172520121800182653000801400653000801408653000901416100002101425700002201446700002401468700001901492856011901511 2012 eng d00aEnhaning Reliable Mobile Multicasting with RaptorQ FEC0 aEnhaning Reliable Mobile Multicasting with RaptorQ FEC c1-4 July a82-873 aA crucial point on the successful deployment of multicast services is the enhanced reliability by means of advanced error control schemes. To this direction Third Generation Partnership Project (3GPP) has standardized exclusively for Multimedia Broadcast/Multicast Services (MBMS) the use of a Forward Error Correction (FEC) mechanism on the application layer based on Raptor codes. Since the standardized systematic, fountain Raptor code is now considered obsolete, the emergence of a new variant of Raptor codes, named RaptorQ, provides enhanced capabilities for mobile multicast services. In this paper, we provide a performance comparison of the standardized Raptor Application Layer FEC (AL-FEC) scheme with the very promising RaptorQ FEC code. We examine the enhancements that RaptorQ introduces on the AL-FEC protection robustness, providing a thorough performance analysis in comparison with the current Raptor FEC scheme. Furthermore, in order to verify the improved performance of RaptorQ, we provide several simulation results utilizing the ns-3 environment, considering the application of both the examined AL-FEC schemes over multicast services for next generation mobile networks.10aFEC10aLTE10aMBMS1 aBouras, Christos1 aPapazois, Andreas1 aKokkinos, Vasileios1 aKanakis, Nikos uhttp://telematics.upatras.gr/telematics/publications/enhaning-reliable-mobile-multicasting-raptorq-fec?language=el01601nas a2200193 4500008004100000245005600041210005600097260001700153300001400170520099100184653000801175653000801183653000901191100002101200700002201221700002401243700001901267856012101286 2012 eng d00aEvaluating RaptorQ FEC over 3GPP Multicast Services0 aEvaluating RaptorQ FEC over 3GPP Multicast Services cAugust 27-31 a257 - 2623 aThird Generation Partnership Project (3GPP) introduced Multimedia Broadcast/Multicast Services (MBMS), in order to efficiently deliver the same content to multiple users over mobile cellular networks. To enhance the download and streaming delivery robustness against packet losses, 3GPP proposes the use of Forward Error Correction (FEC) on the application layer. The Application Layer FEC (AL-FEC) scheme that 3GPP standardized is based on the systematic, fountain Raptor code. In this work, in response to the emergence of an enhanced FEC scheme, we provide a performance evaluation of the existing standardized AL-FEC scheme with the newly introduced RaptorQ code. Introducing a variety of simulation experiments, we analyze the performance behavior of each AL-FEC scheme considering several FEC encoding parameters. Furthermore, we try to verify the improvements that have emerged in AL-FEC providing enhanced capabilities in multicast services over next generation mobile networks.10aFEC10aLTE10aMBMS1 aBouras, Christos1 aPapazois, Andreas1 aKokkinos, Vasileios1 aKanakis, Nikos uhttp://telematics.upatras.gr/telematics/publications/evaluating-raptorq-fec-over-3gpp-multicast-services?language=el01459nas a2200193 4500008004100000245007600041210006900117260002000186300001000206520079400216653000801010653000901018653001001027100002101037700002201058700002401080700002701104856013401131 2012 eng d00aGenetic Optimization for Spectral Efficient Multicasting in LTE Systems0 aGenetic Optimization for Spectral Efficient Multicasting in LTE  c19-21 September a54-593 a

Past research has proposed the usage of assisting cells with Multimedia Broadcast/Multicast Service (MBMS) over a Single Frequency Network (MBSFN) to increase the Spectral Efficiency (SE) of LTE. In this paper we propose and investigate a method for optimizing the power consumption of the network while retaining an acceptable SE for most users. We design an algorithm that makes use of genetic optimization and analytical estimation of the SE. The algorithm is implemented in a novel simulation tool that allows experimentation over various user distributions and LTE deployments similar to the real-world ones. This simulation tool estimates the SE of each user and is able to optimize the network deployment by adjusting the individual transmission power levels for each cell.

10aLTE10aMBMS10aMBSFN1 aBouras, Christos1 aPapazois, Andreas1 aKokkinos, Vasileios1 aAsimakis, Konstantinos uhttp://telematics.upatras.gr/telematics/publications/genetic-optimization-spectral-efficient-multicasting-lte-systems?language=el01544nas a2200193 4500008004100000245004400041210004400085260001500129300001200144520095800156653000801114653000901122100002101131700002201152700002201174700002401196700002401220856010601244 2012 eng d00aMultimedia Broadcasting in LTE Networks0 aMultimedia Broadcasting in LTE Networks bIGI Global a269-2893 a

Long Term Evolution (LTE) constitutes the latest step before the 4th generation (4G) of radio technologies designed to increase the capacity and speed of mobile communications. To support Multimedia Broadcast/Multicast Services (MBMS), LTE offers the functionality to transmit MBMS over Single Frequency Network (MBSFN), where a time-synchronized common waveform is transmitted from multiple cells for a given duration. In MBSFN transmissions, the achieved Spectral Efficiency (SE) is mainly determined by the Modulation and Coding Scheme (MCS) selected. This study proposes and evaluates four approaches for the selection of the MCS that will be utilized for the transmission of the MBSFN data. The evaluation of the approaches is performed for different users? distribution and from SE perspective. Based on the SE measurement, we determine the approach that either maximizes or achieves a target SE for the corresponding users? distribution.

10aLTE10aMBMS1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas1 aKokkinos, Vasileios1 aTsichritzis, George uhttp://telematics.upatras.gr/telematics/publications/multimedia-broadcasting-lte-networks?language=el01989nas a2200193 4500008004100000245005100041210005000092260001800142300001200160520140000172653000801572653000801580653000901588100002101597700002201618700002401640700001901664856011201683 2011 eng d00aAL-FEC for Streaming Services over LTE Systems0 aALFEC for Streaming Services over LTE Systems cOctober 3 - 6 a284-2883 a

The Third Generation Partnership Project (3GPP), recently introduced the evolution of the third generation (3G) cellular networks, the Long Term Evolution (LTE) telecommunication system. A key aspect of LTE specifications is the enhancement of Multimedia Broadcast/Multicast Services (MBMS), where the same content is transmitted to multiple users located in a specific service area. A significant point of the demanding multimedia services is the enhancement of the robustness against packet losses. To this direction, in order to support the efficient point-to-multipoint download and streaming delivery, 3GPP has included an Application Layer Forward Error Correction (AL-FEC) scheme in the MBMS standard. The standardized AL-FEC scheme is based on the systematic, fountain Raptor codes. In this paper, we investigate the application of AL-FEC over the MBMS streaming delivery method. We consider the benefits of AL-FEC for a seamless multimedia streaming transmission to multiple mobile users and we examine how the amount of FEC overhead can be adjusted under different packet loss conditions. For this purpose, we present a variety of realistic simulation scenarios for the performance evaluation of FEC considering several network and FEC encoding parameters. Furthermore, we provide suggestions in order to achieve efficient use of Raptor codes over LTE MBMS streaming services.

10aFEC10aLTE10aMBMS1 aBouras, Christos1 aPapazois, Andreas1 aKokkinos, Vasileios1 aKanakis, Nikos uhttp://telematics.upatras.gr/telematics/publications/al-fec-streaming-services-over-lte-systems?language=el01798nas a2200193 4500008004100000245009000041210006900131300001300200520110000213653000801313653000901321653001001330100002101340700002201361700002201383700002401405700002701429856014801456 2011 eng d00aCombining MBSFN and PTM Transmissions Schemes for Resource Efficiency in LTE Networks0 aCombining MBSFN and PTM Transmissions Schemes for Resource Effic a 56 - 673 aLong Term Evolution (LTE) systems allow the transmission of rich multimedia services by utilizing the Multimedia Broadcast/Multicast Service (MBMS) over a Single Frequency Network (MBSFN). During MBSFN transmission a time-synchronized common waveform is transmitted from multiple cells. The 3rd Generation Partnership Project (3GPP) has specified that Point-to-Multipoint (PTM) transmission can be used in combination with MBSFN to provide MBMS-based services. In this paper we evaluate the combined transmission scheme in terms of Resource Efficiency (RE). The evaluation is performed through simulation experiments for various user distributions and LTE network configurations. The experiments are conducted with the aid of a proposed algorithm, which estimates the Spectral Efficiency (SE) of each cell and the RE of the network, and is also able to formulate the optimal network deployment that maximizes the network?s RE. For each of the examined scenarios, we present the most efficient solution (in terms of RE) selected by our algorithm and we compare it with other transmission schemes.10aLTE10aMBMS10aMBSFN1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas1 aKokkinos, Vasileios1 aAsimakis, Konstantinos uhttp://telematics.upatras.gr/telematics/publications/combining-mbsfn-and-ptm-transmissions-schemes-resource-efficiency-lte-networks?language=el00647nas a2200181 4500008004100000245007900041210006900120260001100189300001500200653000800215653000800223653000900231100002100240700002200261700002400283700002100307856013700328 2011 eng d00aForward Error Correction for Reliable e-MBMS Transmissions in LTE Networks0 aForward Error Correction for Reliable eMBMS Transmissions in LTE bInTech a 353 - 37410aFEC10aLTE10aMBMS1 aBouras, Christos1 aPapazois, Andreas1 aKokkinos, Vasileios1 aTseliou, Georgia uhttp://telematics.upatras.gr/telematics/publications/forward-error-correction-reliable-e-mbms-transmissions-lte-networks?language=el01753nas a2200193 4500008004100000245007700041210006900118260001600187520108700203653000801290653000901298653001001307100002101317700002201338700002201360700002401382700002101406856013201427 2011 eng d00aOptimizing the Combination of MBSFN and PTM Transmissions in LTE Systems0 aOptimizing the Combination of MBSFN and PTM Transmissions in LTE cApril 13-153 aThe 3rd Generation Partnership Project (3GPP) has introduced the evolved Multimedia Broadcast/Multicast Service (e-MBMS) feature for cellular systems as an evolution to the existing MBMS service. To support e-MBMS in Long Term Evolution (LTE) systems, 3GPP recommends the use of Point-to- Multipoint (PTM) transmissions and MBMS over a Single Frequency Network (MBSFN). MBSFN is a new feature where a time-synchronized common waveform is transmitted from multiple cells. In this paper we investigate the provision of MBMS service over a combination of MBSFN and PTM transmission methods. A cost analysis of the MBMS service is presented based on the transmission cost over all the interfaces and nodes of the LTE architecture. We evaluate the performance of this transmission scheme from telecommunication cost perspective and we compare it with other transmission schemes. The performance evaluation has been performed with the aid of a new simulation tool that estimates the cost for the MBMS provision under different network topologies, MBSFN deployments and user distributions.10aLTE10aMBMS10aMBSFN1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas1 aKokkinos, Vasileios1 aTseliou, Georgia uhttp://telematics.upatras.gr/telematics/publications/optimizing-combination-mbsfn-and-ptm-transmissions-lte-systems?language=el01742nas a2200229 4500008004100000245005600041210005500097260002100152300001500173520103400188653000801222653000801230653000901238653001001247100002101257700002201278700002201300700002401322700002701346700002101373856011801394 2011 eng d00aReliable Multicasting over LTE: A Performance Study0 aReliable Multicasting over LTE A Performance Study cJune 28 - July 1 a 603 - 6083 aWith the booming of multimedia services, the 3rd Generation Partnership Project (3GPP) has introduced the evolved Multimedia Multicast/Broadcast Service (e-MBMS) feature for LTE systems. The main objective of MBMS is to introduce real broadcast distribution capabilities into cellular systems. This purposed 3GPP to introduce the MBMS over a Single Frequency Network (MBSFN) operation. In this work we investigate the provision of MBMS service over a combination of MBSFN and PTM transmission schemes. We focus on the file repair procedure, because the distribution of binary data via MBMS must result in 100% error-free downloaded files. In order to achieve this goal, MBMS offers a Forward Error Correction (FEC) mechanism. Our simulation results show that there are some file repair schemes that achieve better performance as far as different network configurations are concerned. Furthermore, we compare all the file recovery methods and evaluate them against various network parameters in a realistic simulation environment.10aFEC10aLTE10aMBMS10aMBSFN1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas1 aKokkinos, Vasileios1 aAsimakis, Konstantinos1 aTseliou, Georgia uhttp://telematics.upatras.gr/telematics/publications/reliable-multicasting-over-lte-performance-study?language=el01548nas a2200181 4500008004100000245006100041210005900102300001500161520096400176653000801140653000901148653001801157653000901175100002101184700002201205700002201227856011701249 2011 eng d00aA study of Forward Error Correction for Mobile Multicast0 astudy of Forward Error Correction for Mobile Multicast a 607 - 6273 a

3GPP has standardized the use of forward error correction for the provision of reliable data transmission in the mobile multicast framework. This error control method inevitably adds a constant overhead in the transmitted data. However, it is so simple as to meet a prime objective for mobile multicast services; that is scalability to applications with thousands of receivers. In this paper we present a study on the impact of application layer forward error correction. We examine whether it is beneficial or not, how the optimal code dimension varies based on network conditions, which parameters affect the optimal code selection, and how they achieve this. Additionally, we focus on one of the most critical aspects in mobile multicast transmission which is power control. The evaluation is performed with the aid of a novel scheme that incorporates the properties of an evolved mobile network, as they are determined by the 3GPP specifications.

10aFEC10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas uhttp://telematics.upatras.gr/telematics/publications/study-forward-error-correction-mobile-multicast?language=el01192nas a2200205 4500008004100000245006100041210006100102260002000163300001500183520052800198653000800726653000800734653000900742100002100751700002200772700002200794700002400816700002400840856012200864 2010 eng d00aAdopting FEC for Reliable Multicasting over LTE Networks0 aAdopting FEC for Reliable Multicasting over LTE Networks cOctober 17 - 21 a 307 - 3103 aThe key feature for the provision of Multimedia Broadcast/Multicast Services (MBMS) in Long Term Evolution (LTE) networks is the Multimedia Broadcast over a Single Frequency Network (MBSFN). On the other hand, the use of Forward Error Correction (FEC) in mobile multicast transmission has significant advantages and the 3rd Generation Partnership Project (3GPP) has adopted the application layer FEC in the MBMS standard. In this paper, we investigate the impact of the application layer FEC over the MBSFN delivery method.10aFEC10aLTE10aMBMS1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas1 aKokkinos, Vasileios1 aTsichritzis, George uhttp://telematics.upatras.gr/telematics/publications/adopting-fec-reliable-multicasting-over-lte-networks?language=el01643nas a2200193 4500008004100000245007800041210006900119260001900188300001200207520099100219653000801210653000801218653000901226653001001235100002101245700002201266700002201288856013901310 2010 eng d00aAdopting forward error correction for multicasting over cellurar networks0 aAdopting forward error correction for multicasting over cellurar c12 - 15 April  a307-3103 a

FEC is an error control method that can be used to augment or replace other methods for reliable data transmission. Such schemes inevitably add a constant overhead in the transmitted data. However, they are so simple as to meet a prime objective for UMTS multicast services, that is scalability to applications with thousands of receivers. This is the reason that 3GPP recommends the use of FEC for MBMS framework. In this paper, we use a probabilistic model for the multicast user distribution in the network and we define a scheme for multicast data delivery that combines FEC with traditional ARQ. It is important that our analysis is compliant with the 3GPP specifications and considers the latest advances in mobile networks. In this framework we investigate the impact of FEC use, we examine whether it is beneficial, how the optimal FEC code dimensioning varies based on the network conditions, which parameters affect the optimal FEC code selection, and how they do it.

10aFEC10aLTE10aMBMS10aMBSFN1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas uhttp://telematics.upatras.gr/telematics/publications/adopting-forward-error-correction-multicasting-over-cellurar-networks?language=el01707nas a2200205 4500008004100000245007000041210006900111260002000180520102200200653000801222653000901230653001001239653000801249100002101257700002201278700002201300700002401322700002401346856013101370 2010 eng d00aEfficient MCS Selection for MBSFN Transmissions over LTE Networks0 aEfficient MCS Selection for MBSFN Transmissions over LTE Network cOctober 20 - 223 aLong Term Evolution (LTE), the next-generation network beyond 3G, is designed to support the explosion in demand for bandwidth-hungry multimedia services that are already experienced in wired networks. To support Multimedia Broadcast/Multicast Services (MBMS), LTE offers functionality to transmit MBMS over a Single Frequency Network (MBSFN), where a time-synchronized common waveform is transmitted from multiple cells for a given duration. This significantly improves the Spectral Efficiency (SE) compared to conventional MBMS operation. The achieved SE is mainly determined by the Modulation and Coding Scheme (MCS) utilized by the LTE physical layer. In this paper we propose and evaluate four approaches for the selection of the MCS that will be utilized for the transmission of the MBSFN data. The evaluation of the approaches is performed for different users? distribution and from SE perspective. Based on the SE measurement, we determine the most suitable approach for the corresponding users? distribution.10aLTE10aMBMS10aMBSFN10aMCS1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas1 aKokkinos, Vasileios1 aTsichritzis, George uhttp://telematics.upatras.gr/telematics/publications/efficient-mcs-selection-mbsfn-transmissions-over-lte-networks?language=el01577nas a2200169 4500008004100000245005400041210005100095300001400146490000700160520104500167653000901212653000901221100002101230700002201251700002201273856011201295 2010 eng d00aAn Efficient Mechanism for UMTS Multicast Routing0 aEfficient Mechanism for UMTS Multicast Routing a802 - 8150 v153 a

In this paper, we present a novel scheme for the multicast transmission of data over Universal Mobile Telecommunications System (UMTS) networks. Apart from the normal multicast transmission over UMTS, we consider the handling of exceptional cases caused by user mobility scenarios. The proposed scheme is in accordance with the current specifications of the Multimedia Multicast/ Broadcast Service (MBMS) defined by the 3rd Generation Partnership Project (3GPP) and introduces minor modifications in the UMTS architecture and the mobility management mechanisms. The proposed scheme is implemented as an ns-2 network simulator module. The performance of the proposed scheme is validated and analyzed through ns-2 simulation experiments. This new module can be employed to investigate various aspects of UMTS multicast. Furthermore, in order to further highlight the contribution of our mechanism, we have implemented two multicast congestion control mechanisms for UMTS and we have measured their performance for MBMS transmissions.

10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas uhttp://telematics.upatras.gr/telematics/publications/efficient-mechanism-umts-multicast-routing?language=el01654nas a2200181 4500008004100000245006100041210006000102260001500162300001500177520105500192653000801247653000901255653001801264100002101282700002201303700002401325856012301349 2010 eng d00aEfficient Power Allocation in E-MBMS Enabled 4G Networks0 aEfficient Power Allocation in EMBMS Enabled 4G Networks bIGI Global a 458 - 4883 a

The plethora of mobile multimedia services that are expected to face high penetration, poses the need for the deployment of a resource economic scheme in Long Term Evolution (LTE) networks. To this direction, the Evolved - Multimedia Broadcast / Multicast Service (E- MBMS) is envisaged to play an instrumental role for LTE proliferation and set the basis for a successful 4th Generation (4G) standardization process. One of the most critical aspects of E- MBMS performance is the selection of the most efficient radio bearer, in terms of power consumption. This chapter presents the prevailing radio bearer selection mechanisms and examines their performance in terms of power consumption. Furthermore, it discusses problems regarding the high power requirements for the realization of E-MBMS and evaluates the proposed techniques/solutions. Finally, this chapter presents a novel mechanism for efficient power control during E-MBMS transmissions that conforms to LTE requirements for simultaneous provision of multiple multimedia sessions.

10aLTE10aMBMS10aPower Control1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios uhttp://telematics.upatras.gr/telematics/publications/efficient-power-allocation-e-mbms-enabled-4g-networks?language=el01674nas a2200205 4500008004100000245005500041210005500096260002000151520103500171653000801206653000801214653000901222653001001231100002101241700002201262700002201284700002401306700002101330856011701351 2010 eng d00aEnhancing FEC Application in LTE Cellular Networks0 aEnhancing FEC Application in LTE Cellular Networks cOctober 20 - 223 a3rd Generation Partnership Project?s (3GPP) Long Term Evolution (LTE) is focused on enhancing the Universal Terrestrial Radio Access (UTRA). Evolved-Multimedia Broadcast and Multicast Service (e-MBMS) uses Multimedia Broadcast over a Single Frequency Network (MBSFN) operation in order to improve its performance. In MBSFN operation, data are transmitted simultaneously over the air from multiple tightly time-synchronized cells. Raptor codes have been standardized as the main application layer Forward Error Correction (FEC) method for e-MBMS due to the advanced error protection they offer and their overall performance. In this study, we investigate the application of FEC in MBSFN-enabled LTE cellular networks and we propose a new scheme that takes into account the properties of MBSFN in order to provide a more efficient operation of FEC during e-MBMS transmissions. The proposed scheme is compared with other file recovery methods and is evaluated against various network parameters in a realistic simulation environment.10aFEC10aLTE10aMBMS10aMBSFN1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas1 aKokkinos, Vasileios1 aTseliou, Georgia uhttp://telematics.upatras.gr/telematics/publications/enhancing-fec-application-lte-cellular-networks?language=el01213nas a2200193 4500008004100000245005600041210005200097260001500149300000800164520062800172653000800800653000800808653000900816653001800825100002100843700002200864700002200886856011100908 2010 eng d00aThe Impact of FEC on Mobile Multicast Power Control0 aImpact of FEC on Mobile Multicast Power Control cMay 9 - 15 a1-63 a3GPP has standardized the use of forward error correction for the provision of reliable data transmission in the mobile multicast framework. In this paper we present a study of the impact of application layer forward error correction on power control during mobile multicast transmission. The evaluation is performed with the aid of a novel scheme that allows the simulation of FEC impact on both streaming delivery and download delivery over a multicast session. It is important that the proposed scheme incorporates the properties of an evolved mobile network, as they are determined by the 3GPP specifications.10aFEC10aLTE10aMBMS10aPower Control1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas uhttp://telematics.upatras.gr/telematics/publications/impact-fec-mobile-multicast-power-control?language=el01740nas a2200181 4500008004100000245007400041210006900115300001500184490000700199520111600206653000801322653000901330653001801339100002101357700002201378700002201400856013601422 2010 eng d00aAn Improved MBMS Power Counting Mechanism towards Long Term Evolution0 aImproved MBMS Power Counting Mechanism towards Long Term Evoluti a 109 - 1190 v433 a

One of the key objectives of beyond 3rd generation mobile networks is the realization of enhanced end-user experience through the provision of rich multimedia services. Multimedia Broadcast/Multicast Services (MBMS) framework epitomizes the increasing popularity of such applications and is envisaged to play an instrumental role for the Long Term Evolution (LTE) proliferation in mobile market. For exploiting resource efficiency, MBMS specifications consider the Counting Mechanism which decides whether it is more efficient to deliver MBMS multicast traffic over Point-to-Point (PTP) or Point-to-Multipoint (PTM) bearers. However, the necessity to further improve MBMS resource efficiency and integrate new technologies in the frame of LTE stresses the need for an advanced Counting Mechanism. In this work we propose a novel Power Counting Mechanism for efficient selection of MBMS bearers. The proposed mechanism optimally utilizes power resources and exploits broadband characteristics and performance enhancements emerged from Multiple Input Multiple Output (MIMO) antennas used in LTE networks.

10aLTE10aMBMS10aPower Control1 aBouras, Christos1 aAlexiou, Antonios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/improved-mbms-power-counting-mechanism-towards-long-term-evolution?language=el01973nas a2200193 4500008004100000245008900041210006900130300001500199490000700214520128900221653000901510653001801519653000901537100002101546700002201567700002401589700002201613856014401635 2010 eng d00aAn Improved Mechanism for Multiple MBMS Sessions Assignment in B3G Cellurar Networks0 aImproved Mechanism for Multiple MBMS Sessions Assignment in B3G  a 671 - 6860 v163 a

In Universal Mobile Telecommunication System (UMTS), the downlink capacity is limited by the base station transmission power. Therefore, power control plays an important role to minimize the transmitted power shared among unicast and multicast users within a cell. In Multimedia Broadcast/Multicast Service (MBMS), power control targets to the efficient utilization of radio and network resources. However, the expected high demand for such services stresses the need for an efficient scheme, capable of dynamically allocating radio resources to parallel MBMS sessions. This paper proposes a power control mechanism for efficient MBMS session assignment in next generation UMTS networks. The mechanism shares efficiently the available power resources of UMTS base stations to MBMS sessions running in the network. Furthermore, the mechanism is evaluated through several realistic scenarios and the results indicate the ability of the mechanism to utilize efficiently the radio resources and to ensure the service continuity when parallel MBMS services run in the network. Our approach is compared with current 3rd Generation Partnership Project (3GPP) approaches, such as these presented in TS 25.346 and in TR 25.922, in order to highlight the enhancements that it provides.

10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/improved-mechanism-multiple-mbms-sessions-assignment-b3g-cellurar-networks?language=el01706nas a2200181 4500008004100000245009700041210006900138260002100207300001300228520102600241653000901267653000901276100002101285700002201306700002401328700002201352856015001374 2010 eng d00aThe Multimedia Broadcast/Multicast Service of the Universal Mobile Telecommunications System0 aMultimedia BroadcastMulticast Service of the Universal Mobile Te bWorld Scientific a 43 - 783 a

The Universal Mobile Telecommunications System (UMTS) constitutes the premier third generation (3G) wireless technology that is dominating the global market. Multicasting is an efficient method of supporting group communication as it allows the transmission of packets to multiple destinations, using fewer network resources. The need for broadcasting and multicasting in UMTS led to the definition of the Multimedia Broadcast/Multicast Service (MBMS) framework, which targets the efficient utilization of radio and network resources of the UMTS network. This chapter introduces the key concepts of UMTS and in particular the MBMS framework of UMTS. Moreover, it investigates the power profiles of several transport channels (common and dedicated) which could be employed for the transmission of MBMS services to mobile users. Problems regarding the high power requirements for the realization of MBMS are also presented. The reader will become familiar with these problems and the proposed techniques/solutions.

10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/multimedia-broadcastmulticast-service-universal-mobile-telecommunications-system?language=el01839nas a2200181 4500008004100000245006700041210006600108260006300174300001500237520117500252653000801427653000901435653001801444100002101462700002201483700002401505856012801529 2010 eng d00aRadio Resource Management for E-MBMS Transmissions towards LTE0 aRadio Resource Management for EMBMS Transmissions towards LTE bAuerbach Publications, CRC Press, Taylor and Francis Group a 331 - 3603 a

Long Term Evolution (LTE) constitutes a key standard that paves the way for the future mobile broadband landscape envisioned by 4th Generation (4G) wireless networks. Actu- ally, LTE addresses the emerging trend for the mass provision of rich multimedia services, such as Mobile TV, in a more power and spectral e±cient way than its predecessors. To this direction, the Evolved - Multimedia Broadcast/Multicast Service (E-MBMS) frame- work is envisaged to play an instrumental role for the LTE proliferation in mobile. E-MBMS constitutes the evolutionary successor of MBMS, which was introduced in the Release 6 of Universal Mobile Telecommunication System (UMTS). MBMS is designed in order to deliver multimedia data from a single source entity to multiple destinations. However, downlink ca- pacity in such networks is limited by base station transmission power. As an aftermath, in MBMS e±cient power allocation techniques should be implemented so as to ensure the mass provision of multimedia applications to mobile users. This chapter presents several techniques and mechanisms used today for MBMS power optimization in next generation cellular networks.

10aLTE10aMBMS10aPower Control1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios uhttp://telematics.upatras.gr/telematics/publications/radio-resource-management-e-mbms-transmissions-towards-lte?language=el01676nas a2200217 4500008004100000245006600041210006500107260002000172300001500192520097500207653000801182653000901190653001001199653000801209100002101217700002201238700002201260700002401282700002401306856012801330 2010 eng d00aSpectral Efficiency Performance of MBSFN-enabled LTE Networks0 aSpectral Efficiency Performance of MBSFNenabled LTE Networks cOctober 11 - 13 a 361 - 3673 aLong Term Evolution (LTE) constitutes the latest step before the 4th generation (4G) of radio technologies designed to increase the capacity and speed of mobile communications. To support Multimedia Broadcast/Multicast Services (MBMS), LTE offers the possibility to transmit Multimedia Broadcast multicast service over a Single Frequency Network (MBSFN), where a time-synchronized common waveform is transmitted from multiple cells for a given duration. This enables over-the-air combining, thus improving the Signal to Interference plus Noise Ratio (SINR) and spectral efficiency (SE) significantly compared to conventional MBMS operation. In this paper, we analytically calculate the SE performance achieved in a MBSFN area for a dynamically changing user topology and different modulation and coding schemes (MCS). Finally, based on the SE measurement, we determine the MCS scheme that either maximizes or achieves a target SE for the corresponding user distribution.10aLTE10aMBMS10aMBSFN10aMCS1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas1 aKokkinos, Vasileios1 aTsichritzis, George uhttp://telematics.upatras.gr/telematics/publications/spectral-efficiency-performance-mbsfn-enabled-lte-networks?language=el01774nas a2200193 4500008004100000245008200041210006900123300001700192520108500209653001801294653000901312653001801321653000901339100002101348700002201369700002401391700002201415856014301437 2009 eng d00aCost Analysis and Efficient Radio Bearer Selection for Multicasting over UMTS0 aCost Analysis and Efficient Radio Bearer Selection for Multicast a 1159 - 11723 aAlong with the widespread deployment of the Third Generation (3G) cellular networks, the fast-improving capabilities of the mobile devices, content, and service providers are increasingly interested in supporting multicast communications over wireless networks and in particular over Universal Mobile Telecommunications System (UMTS). To this direction, the Third Generation Partnership Project (3GPP) is currently standardizing the Multimedia Broadcast/Multicast Service (MBMS) framework of UMTS. In this paper, we present an overview of the MBMS multicast mode of UMTS. We analytically present the multicast mode of the MBMS and analyze its performance in terms of packet delivery cost under various network topologies, cell types, and multicast users? distributions. Furthermore, for the evaluation of the scheme, we consider different transport channels for the transmission of the multicast data over the UMTS Terrestrial Radio-Access Network (UTRAN) interfaces. Finally, we propose a scheme for the efficient radio bearer selection that minimizes total packet delivery cost.10aCost analysis10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/cost-analysis-and-efficient-radio-bearer-selection-multicasting-over-umts?language=el01566nas a2200169 4500008004100000245006400041210006300105260002100168300001500189520098200204653000801186653000901194100002101203700002201224700002401246856012601270 2009 eng d00aEfficient Assignment of Multiple E-MBMS Sessions toward LTE0 aEfficient Assignment of Multiple EMBMS Sessions toward LTE c9 - 11 September a 240 - 2503 aOne of the major prerequisites for Long Term Evolution (LTE) networks is the mass provision of multimedia services to mobile users. To this end, Evolved - Multimedia Broadcast/Multicast Service (E-MBMS) is envisaged to play an instrumental role during LTE standardization process and ensure LTE?s proliferation in mobile market. E-MBMS targets at the economic delivery, in terms of power and spectral efficiency, of multimedia data from a single source entity to multiple destinations. This paper proposes a novel mechanism for efficient radio bearer selection during E-MBMS transmissions in LTE networks. The proposed mechanism is based on the concept of transport channels combination in any cell of the network. Most significantly, the mechanism manages to efficiently deliver multiple E-MBMS sessions. The performance of the proposed mechanism is evaluated and compared with several radio bearer selection mechanisms in order to highlight the enhancements that it provides.10aLTE10aMBMS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios uhttp://telematics.upatras.gr/telematics/publications/efficient-assignment-multiple-e-mbms-sessions-toward-lte?language=el01496nas a2200181 4500008004100000245008000041210006900121260001600190300001800206520085200224653000901076653001801085653000901103100002101112700002201133700002401155856013501179 2009 eng d00aAn Efficient Mechanism for Power Control Optimization in MBMS Enabled UTRAN0 aEfficient Mechanism for Power Control Optimization in MBMS Enabl c5 - 8 April a 1292 - 1297 3 aThis paper proposes a power control mechanism for the efficient radio bearer selection in the Multimedia Broadcast/Multicast Service (MBMS) framework of Universal Mobile Telecommunications System (UMTS). The selection of the most efficient transport channel in terms of power consumption is a key point for MBMS enabled UMTS networks, since a wrong transport channel selection for the transmission of the MBMS data could result to a significant decrease in the total capacity of the network. Different UMTS transport channels and power saving techniques are examined and an algorithm that selects the most efficient combination of the above parameters is proposed. The proposed MBMS power control mechanism selects the transport channel that minimizes the base station?s transmission power in every cell of the network that serves multicast users.10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios uhttp://telematics.upatras.gr/telematics/publications/efficient-mechanism-power-control-optimization-mbms-enabled-utran?language=el01675nas a2200169 4500008004100000245007300041210006900114260001800183520106700201653000801268653000901276653001801285100002101303700002201324700002401346856013501370 2009 eng d00aAn Enhanced MBMS Power Control Mechanism towards Long Term Evolution0 aEnhanced MBMS Power Control Mechanism towards Long Term Evolutio c22 - 24 April3 aLong Term Evolution (LTE) promises the delivery of rich multimedia services in a more power and spectral efficient way than its predecessor Universal Mobile Telecommunication System (UMTS). To this direction, the newly introduced Enhanced - Multimedia Broadcast/Multicast Service (E-MBMS) framework is envisaged to play a fundamental role during the LTE standardization. E-MBMS constitutes the successor of MBMS which was introduced in the Release 6 of UMTS in order to deliver multimedia data from a single source entity to multiple destinations. This paper proposes a novel mechanism for efficient radio bearer selection during E-MBMS transmissions in LTE networks. The proposed mechanism is based on the concept of transport channels combination (pointto- point and/or point-to-multipoint radio bearers) in any cell/sector of the network in which multicast users are residing. The mechanism is evaluated through several realistic scenarios and is compared with several radio bearer selection mechanisms in order to highlight the enhancements that it provides.10aLTE10aMBMS10aPower Control1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios uhttp://telematics.upatras.gr/telematics/publications/enhanced-mbms-power-control-mechanism-towards-long-term-evolution?language=el01931nas a2200193 4500008004100000245008400041210006900125260002000194300001500214520125800229653000801487653000901495653001801504653000901522100002101531700002201552700002401574856013901598 2009 eng d00aAn Enhanced Mechanism for Efficient Assignment of Multiple sessions towards LTE0 aEnhanced Mechanism for Efficient Assignment of Multiple sessions c26 - 30 October a 384 - 3913 aThe provision of rich multimedia services, such as Mobile TV, is considered of key importance for the Long Term Evolution (LTE) proliferation in mobile market. To this direction, Evolved - Multimedia Broadcast/Multicast Service (E-MBMS) that targets at the efficient delivery of multimedia data from a single source entity to multiple destinations, is envisaged to play an instrumental role during LTE standardization process. However, both LTE and E-MBMS performance are limited by the base station?s transmission power. As an aftermath, efficient power allocation techniques should be implemented so as to ensure the mass provision of multimedia applications to mobile users. This paper proposes a novel mechanism for efficient radio bearer selection during E-MBMS transmissions in LTE networks. The proposed mechanism is based on the concept of transport channels combination in any cell of the network. Most significantly, the mechanism exploits the performance enhancements emerged from Multiple Input Multiple Output (MIMO) antennas used in LTE networks and manages to efficiently deliver multiple E-MBMS sessions. The proposed mechanism is thoroughly evaluated and compared with several radio bearer selection mechanisms existing in bibliography.10aLTE10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios uhttp://telematics.upatras.gr/telematics/publications/enhanced-mechanism-efficient-assignment-multiple-sessions-towards-lte?language=el01699nas a2200157 4500008004100000245007000041210006900111520113100180653000801311653000901319653001801328100002101346700002201367700002401389856012801413 2009 eng d00aEvaluation of Different Power Saving Techniques for MBMS Services0 aEvaluation of Different Power Saving Techniques for MBMS Service3 aOver the last years we have witnessed an explosive growth of multimedia computing, wireless communication and applications. Following the rapid increase in penetration rate of broadband services, the Third Generation Partnership Project (3GPP) is currently standardizing the Evolved-Multimedia Broadcast/Multicast Service (E-MBMS) framework of Long Term Evolution (LTE), the successor ofUniversalMobile Telecommunications System (UMTS).MBMS constitutes a point-to-multipoint downlink bearer service that was designed to significantly decrease the required radio and wired link resources. However, several obstacles regarding the high-power requirements should be overcome for the realization of MBMS. Techniques, such as Macrodiversity Combining and Rate Splitting, could be utilized to reduce the power requirement of delivering multicast traffic toMBMS users. In this paper, we analytically present several power saving techniques and analyze their performance in terms of power consumption. We provide simulation results that reveal the amount of power that is saved and reinforce the need for the usage of such techniques.10aLTE10aMBMS10aPower Control1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios uhttp://telematics.upatras.gr/telematics/publications/evaluation-different-power-saving-techniques-mbms-services?language=el01860nas a2200181 4500008004100000245006600041210006600107260001800173520123500191653000801426653000901434653001801443100002101461700002201482700002401504700002201528856012801550 2009 eng d00aOptimal MBMS Power Allocation Exploiting MIMO in LTE Networks0 aOptimal MBMS Power Allocation Exploiting MIMO in LTE Networks c26 - 29 April3 aIn the frame of the Long Term Evolution (LTE) of mobile networks, the provision of rich multimedia services, such as Mobile TV, is considered of key importance for the LTE proliferation in mobile market. To this end, Multimedia Broadcast/Multicast Service (MBMS) is envisaged to play an instrumental role during LTE standardization process. MBMS was introduced in the Release 6 of Universal Mobile Telecommunication System (UMTS) in order to deliver multimedia data from a single source entity to multiple destinations. However, downlink capacity in such networks is limited by base station transmission power. As an aftermath, in MBMS efficient power allocation techniques should be implemented so as to ensure the mass provision of multimedia applications to mobile users. In this paper we propose a power control scheme for efficient selection of MBMS bearers. The proposed mechanism on the one hand manages to economically utilize power resources during MBMS transmissions, while on the other hand exploits the performance enhancements emerged from Multiple Input Multiple Output (MIMO) antennas used in LTE networks. Simulation results indicate that the proposed scheme results to significant power and capacity improvements.10aLTE10aMBMS10aPower Control1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/optimal-mbms-power-allocation-exploiting-mimo-lte-networks?language=el01682nas a2200181 4500008004100000245006500041210006500106260001600171300001500187520106700202653000901269653001801278653000901296100002101305700002201326700002201348856013001370 2009 eng d00aOptimizing MBMS Power Allocation Through HSDPA Transmissions0 aOptimizing MBMS Power Allocation Through HSDPA Transmissions c24 - 28 May a 327 - 3323 aLong Term Evolution (LTE) promises the delivery of rich multimedia services in a more power and spectral efficient way than its predecessor Universal Mobile Telecommunication System (UMTS). To this direction, the newly introduced Enhanced - Multimedia Broadcast/Multicast Service (E-MBMS) framework is envisaged to play a fundamental role during the LTE standardization. E-MBMS constitutes the successor of MBMS which was introduced in the Release 6 of UMTS in order to deliver multimedia data from a single source entity to multiple destinations. This paper proposes a novel mechanism for efficient radio bearer selection during E-MBMS transmissions in LTE networks. The proposed mechanism is based on the concept of transport channels combination (point to-point and/or point-to-multipoint radio bearers) in any cell/sector of the network in which multicast users are residing. The mechanism is evaluated through several realistic scenarios and is compared with several radio bearer selection mechanisms in order to highlight the enhancements that it provides.10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/optimizing-mbms-power-allocation-through-hsdpa-transmissions?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=el01543nas a2200181 4500008004100000245009000041210006900131260001800200300001500218520087300233653000901106653001801115653000901133100002101142700002201163700002401185856015201209 2008 eng d00aBalancing between Power Optimization and Iub Efficiency in MBMS enabled UMTS Networks0 aBalancing between Power Optimization and Iub Efficiency in MBMS  c1 - 3 October a 355 - 3683 aMulticast transmission is one of the major goals for Universal Mobile Telecommunication System (UMTS) that motivated the 3rd Generation Partnership Project (3GPP) to launch the Multimedia Broadcast/Multicast Service (MBMS) framework. MBMS constitutes a significant step towards the so-called Mobile Broadband, since it allows the efficient utilization of network and radio resources. One of most important problems that MBMS is currently facing is the assignment of the appropriate transport channel for the transmission of MBMS data. This paper proposes an alternative solution to this problem, by introducing a cost-based scheme for the efficient radio bearer selection that minimizes the overall delivery cost. Our approach, calculates the telecommunication cost over the most crucial interfaces of UMTS; and based on this cost selects the appropriate radio bearer.10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios uhttp://telematics.upatras.gr/telematics/publications/balancing-between-power-optimization-and-iub-efficiency-mbms-enabled-umts-networks?language=el01422nas a2200157 4500008004100000245005000041210004800091260001600139520091600155653000901071653000901080100002101089700002201110700002201132856011001154 2008 eng d00aBridging UMTS and Multicast Routing in ns - 20 aBridging UMTS and Multicast Routing in ns 2 c3 - 7 March3 aIn this paper, we present the design and the implementation of a novel scheme for the multicast transmission of data over Universal Mobile Telecommunications System (UMTS) networks. The proposed scheme is implemented as an ns-2 network simulator module which can be employed to investigate various aspects of UMTS multicast. Apart from the normal multicast transmission over UMTS, we consider the handling of exceptional cases induced by user mobility scenarios. The proposed scheme is in accordance with the current specifications of the Multimedia Multicast/Broadcast Service (MBMS) defined by the 3rd Generation Partnership Project (3GPP) and introduces minor modifications in the UMTS architecture and the mobility management mechanisms. The performance of the proposed scheme is validated and analyzed through simulation experiments. Finally, the simulation results are presented along with their analysis.10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas uhttp://telematics.upatras.gr/telematics/publications/bridging-umts-and-multicast-routing-ns-2?language=el01732nas a2200193 4500008004100000245006700041210006700108260002100175300001100196520108000207653000901287653001801296653000901314100002101323700002201344700002401366700002201390856012601412 2008 eng d00aEfficient Assignment of Multiple MBMS Sessions in B3G Networks0 aEfficient Assignment of Multiple MBMS Sessions in B3G Networks c22 - 25 Septemer a 1 - 53 aIn Universal Mobile Telecommunication System (UMTS), the downlink capacity is limited by the base station transmission power. Therefore, power control plays an important role to minimize the transmitted power shared among unicast and multicast users within a cell. In Multimedia Broadcast/Multicast Service (MBMS), power control targets to the efficient utilization of radio and network resources. However, the expected high demand for such services stresses the need for an efficient scheme, capable of dynamically allocating radio resources to parallel MBMS sessions. This paper proposes a power control mechanism for efficient MBMS session assignment in next generation UMTS networks. The mechanism shares efficiently the available power resources of UMTS base stations to MBMS sessions running in the network. Furthermore, the mechanism is evaluated through several realistic scenarios and the results indicate the ability of the mechanism to utilize efficiently the radio resources and to ensure the service continuity when parallel MBMS services running in the network.10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/efficient-assignment-multiple-mbms-sessions-b3g-networks?language=el01529nas a2200169 4500008004100000245006000041210006000101260001100161300001300172520096900185653000901154653000901163100002101172700002201193700002201215856012201237 2008 eng d00aEfficient Delivery of MBMS Multicast Traffic over HSDPA0 aEfficient Delivery of MBMS Multicast Traffic over HSDPA c6 July a 50 - 553 aMultimedia Broadcast/Multicast Service (MBMS) and High-Speed Downlink Packet Access (HSDPA) are two key technologies that constitute a significant step towards the Mobile Broadband. MBMS was introduced by the third Generation Partnership Project (3GPP) in order to support broadcast and multicast communication over wireless networks and in particular over Universal Mobile Telecommunications System (UMTS). Concurrently, HSDPA aims to ensure the transmission of high peak data rates and increase system capacity. In this paper we evaluate the performance of MBMS multicast transmission over the premier transport channel used in HSDPA, named High Speed-Downlink Shared Channel (HS-DSCH). Due to the fact that downlink transmission power is the scarcest resource in UMTS networks, the evaluation is performed through an analytical dimensioning of the MBMS downlink transmission power. Furthermore, the impacts of power allocation on MBMS capacity are investigated.10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/efficient-delivery-mbms-multicast-traffic-over-hsdpa?language=el01424nas a2200157 4500008004100000245006700041210006400108300001500172520087000187653000901057653000901066100002101075700002201096700002601118856012201144 2008 eng d00aAn Efficient Mechanism for Multicast Data Transmission in UMTS0 aEfficient Mechanism for Multicast Data Transmission in UMTS a 455 - 4713 aIn this paper, we present an efficient scheme for the multicast transmission of the data in the Universal Mobile Telecommunications System (UMTS). We take advantage of the tree topology of the examined network and we introduce the use of Routing Lists (RLs) in the nodes of the UMTS. The adoption of these lists leads to the decrement of the transmitted packets and to the efficient use of network resources in the multicast transmission of the data. We describe in detail the appropriate steps for the successful multicast transfer of data. Furthermore, we analyze the handling of special cases such as user mobility scenarios. Especially, the various handover types are examined along with the Serving Radio Network Subsystem relocation procedure. Finally, we implement our approach in the NS-2 simulator and we present the performance of the multicast mechanism.10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aAntonellis, Dimitrios uhttp://telematics.upatras.gr/telematics/publications/efficient-mechanism-multicast-data-transmission-umts?language=el01790nas a2200181 4500008004100000245008700041210006900128260002100197520112300218653000901341653001801350653000901368100002101377700002201398700002401420700002201444856014201466 2008 eng d00aEvaluation of Different Radio Bearer Selection Approaches for MBMS in B3G Networks0 aEvaluation of Different Radio Bearer Selection Approaches for MB c24 - 27 November3 aThe spread of multimedia data has drastically differentiated the current landscape of Universal Mobile Telecommunication System (UMTS) networks, posing the need for further enhancements in its Radio Resource Management (RRM) strategies. Introduced in 3rd Generation Partnership Project (3GPP) Release 6, the Multimedia Broadcast/Multicast Services (MBMS) framework aims at the efficient usage of network and radio resources for the transmission of multimedia services. The main requirement during the provision of MBMS multicast services is to minimize the transmission power of UMTS base stations. To this direction, several mechanisms have been proposed that either allow a simultaneous deployment of Point-to-Point (PTP) and Point-to-Multipoint (PTM) transmissions, or a single transport channel deployment (PTP or PTM) in a cell at any given time. Main objective of this paper is to study these mechanisms, compare them in terms of power consumption, underline the advantages that they may offer; and finally to propose enhancements that will ensure the lowest possible power consumption during MBMS transmissions.10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/evaluation-different-radio-bearer-selection-approaches-mbms-b3g-networks?language=el01480nas a2200145 4500008004100000245005400041210005300095300001400148520099600162653000901158653000901167100002101176700002201197856011501219 2008 eng d00aMulticast in UMTS: Evaluation and Recommendations0 aMulticast in UMTS Evaluation and Recommendations a463 - 4813 aIt is known that multicasting is an efficient method of supporting group communication as it allows the transmission of packets to multiple destinations using fewer network resources. Along with the widespread deployment of the third generation cellular networks, the fast-improving capabilities of the mobile devices, content and service providers are increasingly interested in supporting multicast communications over wireless networks and in particular over Universal Mobile Telecommunications System (UMTS). Multicasting is a more efficient method of supporting group communication than unicasting or broadcasting, as it allows transmission and routing of packets to multiple destinations using fewer network resources. In this paper the three above mentioned methods of supporting group communication are analyzed in terms of their performance. The critical parameters of primary interest for the evaluation of any method are the packet delivery cost and the scalability of the method.10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios uhttp://telematics.upatras.gr/telematics/publications/multicast-umts-evaluation-and-recommendations?language=el01920nas a2200193 4500008004100000245009500041210006900136260002000205300001500225520121000240653000901450653001801459653000901477100002101486700002201507700002401529700002201553856015101575 2008 eng d00aA Novel Mechanism for Radio Capacity Maximization during MBMS transmission in B3G Networks0 aNovel Mechanism for Radio Capacity Maximization during MBMS tran c27 - 31 October a 185 - 1923 aThis paper proposes a novel mechanism for efficient power control during multicast transmissions in Beyond 3rd Generation (B3G) mobile networks. The mechanism utilizes optimally the available power resources of Universal Mobile Telecommunication System (UMTS) base stations, resulting to network capacity maximization. The proposed mechanism is based on the concept of transport channels combination (point-topoint and/or point-to-multipoint radio bearers) in any cell/sector of the network in which Multimedia Broadcast/Multicast Service (MBMS) users are residing. In particular, the transport channel combination that minimizes the transmission power of the base station is selected for the transmission of the MBMS traffic to the corresponding cell. The mechanism is evaluated through several realistic scenarios and the results indicate the ability of the mechanism to utilize optimally the radio resources of the network. Furthermore, our approach is compared with several power control mechanisms existing in the bibliography, including the 3rd Generation Partnership Project (3GPP) approaches (presented in 3GPP TS 25.346 and 3GPP TR 25.922), in order to highlight the enhancements that it provides10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/novel-mechanism-radio-capacity-maximization-during-mbms-transmission-b3g-networks?language=el01802nas a2200181 4500008004100000245008400041210006900125260002900194300001300223520114300236653000901379653001801388653000901406100002101415700002201436700002201458856014001480 2008 eng d00aA Novel Power Counting Mechanism for Enhanced MBMS Performance in UMTS Networks0 aNovel Power Counting Mechanism for Enhanced MBMS Performance in  c30 September - 2 October a 57 - 683 aOne of the key objectives of Universal Mobile Telecommunications System (UMTS) is the realization of enhanced end-user experience through the provision of rich multimedia services, ensuring in parallel an economical delivery cost for service providers. Multimedia Broadcast/Multicast Services (MBMS) framework of UMTS epitomizes the increasing popularity of such applications by efficiently delivering multimedia traffic to a large number of users and optimizing the radio interface of UMTS networks. For exploiting resource efficiency, MBMS specifications consider the Counting Mechanism which decides whether it is more economic to deliver MBMS multicast traffic over point-to-point (PTP) or point-to-multipoint (PTM) bearers. However, the necessity to further improve MBMS resource efficiency and integrate new technologies such as High Speed Downlink Packet Access (HSDPA) stresses the need for an advanced Counting Mechanism. To this direction, in this paper we propose a novel Power Counting Mechanism which performs optimal power resource utilization and incorporates the HSDPA broadband extension of UMTS for enhanced performance.10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/novel-power-counting-mechanism-enhanced-mbms-performance-umts-networks?language=el01822nas a2200181 4500008004100000245005700041210005700098260001500155300001500170520123700185653000901422653001801431653000901449100002101458700002201479700002401501856011501525 2008 eng d00aPower Saving Methods for MBMS Transmissions in UTRAN0 aPower Saving Methods for MBMS Transmissions in UTRAN c6 - 9 July a 374 - 3793 aThe demand for wireless multimedia communications thrives in today?s consumer and corporate market. The need to evolve multimedia applications and services is at a critical point given the proliferation and integration of wireless systems. Multimedia Broadcast Multicast Services (MBMS) was introduced in Third Generation Partnership Project (3GPP) Release 6 in order to more efficiently use network and radio resources for the transmission of multimedia data, both in the core network and most importantly in the air interface of UTRAN (UMTS Terrestrial Radio Access Network). However, several obstacles, regarding the high power requirements, should be overcome for the realization of MBMS. The fact that Node B?s transmission power is a limited resource and must be shared among all MBMS users in a cell indicates the need for power control during MBMS transmissions. Several techniques, such as Dynamic Power Setting and Macro Diversity Combining, have been proposed in order to reduce the power requirements of delivering multicast traffic to MBMS users. This paper examines the efficiency of the utilization of these power saving techniques, by presenting simulation results that will reveal the amount of power that is saved.10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios uhttp://telematics.upatras.gr/telematics/publications/power-saving-methods-mbms-transmissions-utran?language=el01483nas a2200181 4500008004100000245005300041210005300094260001500147300001500162520091500177653001801092653000901110653000901119100002101128700002201149700002201171856010801193 2007 eng d00aCost Analysis of the MBMS Multicast Mode of UMTS0 aCost Analysis of the MBMS Multicast Mode of UMTS c1 - 4 July a 797 - 8023 aAlong with the widespread deployment of the third generation cellular networks, the fast-improving capabilities of the mobile devices, content and service providers are increasingly interested in supporting multicast communications over wireless networks and in particular over Universal Mobile Telecommunications System (UMTS). To this direction, the third Generation Partnership Project (3GPP) is currently standardizing the Multimedia Broadcast/Multicast Service (MBMS) framework of UMTS. In this paper, we present an overview of the MBMS multicast mode of UMTS. We analytically present the multicast mode of the MBMS and analyze its performance in terms of packet delivery cost under various network topologies, cell types and multicast users? distributions. Furthermore, for the evaluation of the scheme, we consider different transport channels for the transmission of the data over the UTRAN interfaces.10aCost analysis10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/cost-analysis-mbms-multicast-mode-umts?language=el01623nas a2200169 4500008004100000245004500041210004500086260002000131520109500151653000901246653000901255100002101264700002201285700002401307700002201331856010001353 2007 eng d00aEvaluation of the multicast mode of MBMS0 aEvaluation of the multicast mode of MBMS c3 - 6 September3 aMulticasting is an efficient way for delivering rich multimedia applications to large user groups as it allows the transmission of packets to multiple destinations using fewer network resources. Content and service providers are increasingly interested in supporting multicast communications over wireless networks and in particular over Universal Mobile Telecommunications System (UMTS). To this direction, the third Generation Partnership Project (3GPP) is currently standardizing the Multimedia Broadcast/Multicast Service (MBMS) framework of UMTS. In this paper, we present an overview of the MBMS multicast mode of UMTS. We analytically present the multicast mode of the MBMS and analyze its performance in terms of packet delivery cost under various network topologies, cell environments and multicast users? distributions. Furthermore, for the evaluation of the scheme, we consider different transport channels for the transmission of the data over the UTRAN interfaces and propose a cost based scheme for the efficient radio bearer selection that minimizes the packet delivery cost.10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/evaluation-multicast-mode-mbms?language=el01587nas a2200193 4500008004100000245006100041210006100102260001100163300001300174520095800187653000901145653001801154653000901172100002101181700002201202700002401224700002201248856012301270 2007 eng d00aMBMS Power Planning in Macro and Micro Cell Envirohments0 aMBMS Power Planning in Macro and Micro Cell Envirohments c1 July a 33 - 383 aMultimedia Broadcast Multicast Services (MBMS), introduced in Third Generation Partnership Project (3GPP) Release 6, is a point-to-multipoint downlink bearer service that addresses the need for the efficient usage of the expensive radio resources. Power control is one of the most important aspects in MBMS due to the fact that Node B?s transmission power is a limited resource and must be shared among all MBMS users in a cell. Consequently, the analysis of transmitted power plays a fundamental role in the planning and optimization process of Universal Mobile Telecommunications System (UMTS) radio access networks. This paper investigates several factors affecting Node B?s transmission power levels such as, cell deployment, propagation models, Quality of Service (QoS) requirements, users? distributions and mobility issues. Finally, different transport channels for the transmission of the multicast data over the UTRAN interfaces are considered.10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/mbms-power-planning-macro-and-micro-cell-envirohments?language=el01201nas a2200169 4500008004100000245005100041210004800092260002200140300001500162520066100177653000900838653000900847100002100856700002200877700002200899856011000921 2007 eng d00aMulticast in UMTS: Adopting TCP - Friendliness0 aMulticast in UMTS Adopting TCP Friendliness c12 - 14 September a 433 - 4443 aIn this paper, we present a novel mechanism for the multicast congestion control over UMTS networks. The proposed mechanism is based on the well known TCP-Friendly Multicast Congestion Control (TFMCC) scheme. The key challenge in the design of the new scheme lies in improving the TFMCC mechanism to cope with the packet losses caused by either the temporary or the permanent degradation of the wireless channels. The proposed scheme introduces minor modifications in the UMTS nodes with respect to the computing power of the mobile terminals. Finally, our approach is implemented in the ns-2 network simulator and is evaluated it under various conditions.10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas uhttp://telematics.upatras.gr/telematics/publications/multicast-umts-adopting-tcp-friendliness?language=el01411nas a2200181 4500008004100000245007200041210006900113260001700182300001100199520079000210653000901000653001801009653000901027100002101036700002201057700002201079856012801101 2007 eng d00aA Power Control Scheme for Efficient Radio Bearer Selection in MBMS0 aPower Control Scheme for Efficient Radio Bearer Selection in MBM c18 - 21 June a 1 - 83 aThis paper proposes a power control scheme for the efficient radio bearer selection in the Multimedia Broadcast/Multicast Service (MBMS) framework of Universal Mobile Telecommunications System (UMTS). The choice of the most efficient transport channel in terms of power consumption is a key point for the MBMS since a wrong transport channel selection for the transmission of the MBMS data could result to a significant decrease in the total capacity of the system. Different UMTS transport channels are examined and an algorithm that defines the switching point between dedicated and common radio bearers is proposed. The proposed MBMS power control scheme selects the transport channel that minimizes the Node B?s transmission power in every cell of the network with multicast users.10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/power-control-scheme-efficient-radio-bearer-selection-mbms?language=el01875nas a2200193 4500008004100000245006600041210006600107260002000173300001500193520122000208653000901428653001801437653000901455100002101464700002201485700002401507700002201531856012801553 2007 eng d00aPower Efficient Radio Bearer Selection in MBMS Multicast Mode0 aPower Efficient Radio Bearer Selection in MBMS Multicast Mode c22 - 26 October a 261 - 2683 aMultimedia Broadcast Multicast Services (MBMS) was introduced in Third Generation Partnership Project (3GPP) Release 6 in order to address the need for the efficient usage of the expensive radio resources. The goal of this effort is to support downlink streaming and download-and-play type services to large groups of users. From the radio perspective, MBMS includes point-to-point (PtP) and point-to-multipoint (PtM) modes. The fact that Node B?s transmission power is a limited resource and must be shared among all MBMS users in a cell indicates the need for power control during an MBMS service. Consequently, the analysis of the transmitted power plays a fundamental role in the planning and optimization process of Universal Mobile Telecommunications System (UMTS) radio access networks. In this paper we investigate the factors that affect the Node B?s transmission power levels during an MBMS session, such as, cell deployment, propagation models, users? distributions and mobility issues. To this direction, the transport channels in the downlink, currently existing in UMTS which could be used to transmit the multicast data over the UMTS Terrestrial Radio- Access Network (UTRAN) interfaces are examined.10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios1 aRekkas, Evangelos uhttp://telematics.upatras.gr/telematics/publications/power-efficient-radio-bearer-selection-mbms-multicast-mode?language=el01689nas a2200181 4500008004100000245005100041210005100092260001500143300001300158520112000171653000901291653001801300653000901318100002101327700002201348700002401370856011301394 2007 eng d00aPower Saving Techniques in MBMS Multicast Mode0 aPower Saving Techniques in MBMS Multicast Mode c26 October a 62 - 693 aMultimedia Broadcast Multicast Services (MBMS) was introduced in Third Generation Partnership Project (3GPP) Release 6 in order to more efficiently use network and radio resources for the transmission of multimedia services both in the core network and, most importantly, in the air interface of UTRAN (UMTS Terrestrial Radio Access Network). From the radio perspective, MBMS includes point-to-point (PtP) and pointto- multipoint (PtM) modes. The latter aims to overcome network congestion when a large number of users request the same content. One of the most important aspects in MBMS is power control. The fact that Node B?s transmission power is a limited resource and must be shared among all MBMS users in a cell indicates the need for power control during an MBMS service. Techniques, such us rate splitting and mixed usage of transport channels can be used to reduce the power requirement of delivering multicast traffic for MBMS users. To this direction, this paper presents simulation results that will reinforce the need for the usage of such techniques and will reveal the amount of power that is saved.10aMBMS10aPower Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aKokkinos, Vasileios uhttp://telematics.upatras.gr/telematics/publications/power-saving-techniques-mbms-multicast-mode?language=el01326nas a2200169 4500008004100000245005900041210005600100260001600156520075800172653000900930653000900939100002100948700002200969700002600991700002201017856011701039 2006 eng d00aAn Efficient Multicast Packet Delivery Scheme for UMTS0 aEfficient Multicast Packet Delivery Scheme for UMTS c2-6 October3 aIn this paper we present an efficient scheme for the multicast transmission of the data in the Universal Mobile Telecommunications System (UMTS). We take advantage of the tree topology of the examined network and we introduce the use of Routing Lists (RLs) in the nodes of the UMTS. The adoption of these lists leads to the decrement of the transmitted packets and the efficient use of network resources during the multicast transmission of the data. We describe in detail the necessary steps for the successful multicast transfer of data. Furthermore, we analyze the handling of special cases such as user mobility scenarios. Especially, the various handover types are examined along with the Serving Radio Network Subsystem (SRNS) relocation procedure10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aAntonellis, Dimitrios1 aPapazois, Andreas uhttp://telematics.upatras.gr/telematics/publications/efficient-multicast-packet-delivery-scheme-umts?language=el01280nas a2200169 4500008004100000245007000041210006900111260001700180300001100197520068700208653000900895653000900904100002100913700002200934700002600956856012800982 2006 eng d00aEvaluating Different One to Many Packet Delivery Schemes for UMTS0 aEvaluating Different One to Many Packet Delivery Schemes for UMT c26 - 29 June a 66-723 aIt is known that multicasting is an efficient method of supporting group communication as it allows the transmission of packets to multiple destinations using fewer network resources. Thus, service providers are increasingly interested in supporting multicast communications over wireless networks and in particular over UMTS. Multicasting is a more efficient method of supporting group communication than unicasting or broadcasting, as it allows transmission and routing of packets to multiple destinations using fewer network resources. In this paper the three above mentioned methods of supporting group communication are analyzed in terms of their performance.10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aAntonellis, Dimitrios uhttp://telematics.upatras.gr/telematics/publications/evaluating-different-one-many-packet-delivery-schemes-umts?language=el01237nas a2200169 4500008004100000245005500041210005200096260001600148300001500164520069000179653000900869653000900878100002100887700002200908700002600930856011100956 2006 eng d00aA Multicast Approach for UMTS: A Performance Study0 aMulticast Approach for UMTS A Performance Study c15 - 19 May a 1086-10913 aIn this paper, a multicast scheme for UMTS which only requires in- significant modifications in the current UMTS network infrastructure is ana- lyzed. We analytically present the multicast routing mechanism behind our scheme as well as the multicast group management functionality of it. Further- more, we present an evaluation of our scheme in terms of its performance. The critical parameters for the evaluation of the scheme are the number of multicast users within the multicast group, the amount of data sent to the multicast users, the density of the multicast users within the cells and the type of transport channel used for the transmission of the multicast data over the air.10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aAntonellis, Dimitrios uhttp://telematics.upatras.gr/telematics/publications/multicast-approach-umts-performance-study?language=el01729nas a2200169 4500008004100000245008300041210006900124260001400193300001300207520111000220653000901330653000901339100002101348700002201369700002601391856014201417 2006 eng d00aA Multicast Packet Forwarding Mechanism for WCDMA Networks using Routing Lists0 aMulticast Packet Forwarding Mechanism for WCDMA Networks using R c6 October a 27 - 343 aThis paper proposes a multicast scheme for the packet forwarding mechanism in the Universal Mobile Telecommunications System (UMTS). This scheme relies on the introduction of the Permanent Multicast Routing List (PMRL) and Temporary Multicast Routing List (TMRL) in each node of the network except UEs. In the PMRL we record the nodes of the next level that the messages for every multicast group should be forwarded. The TMRL is useful for the temporary record of information from the path from the mobile users to the GGSN. Additionally, a Multicast Group List (MGL) is kept in the GGSN which records the members of each multicast group. These lists lead to the decrement of the transmitted packets and the more efficient use of the network resources in the multicast routing in UMTS. We analyze the exact steps that the multicast packets are transmitted to the members of each multicast group. Furthermore, special issues such as joining/leaving a multicast service are described. Our simulation results show that the proposed mechanism for the multicast packet forwarding in UMTS performs efficiently.10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aAntonellis, Dimitrios uhttp://telematics.upatras.gr/telematics/publications/multicast-packet-forwarding-mechanism-wcdma-networks-using-routing-lists?language=el01670nas a2200169 4500008004100000245005300041210005300094260002200147300001300169520111600182653000901298653000901307100002101316700002201337700002601359856011501385 2006 eng d00aSupporting Group Communication in WCDMA Networks0 aSupporting Group Communication in WCDMA Networks c20 - 22 September a 13 - 243 aIt is known that multicast is an efficient method of supporting group communication as it allows the transmission of the packets to multiple destinations using fewer network resources. Along with the widespread deployment of the third generation cellular networks and the fast-improving capabilities of the mobile devices, content and service providers are increasingly interested in supporting multicast communications over wireless networks and in particular over Universal Mobile Telecommunications System (UMTS). In this paper, a multicast scheme for UMTS is analyzed. We analytically present the multicast routing mechanism behind our scheme as well as the multicast group management functionality of the scheme. Furthermore, we present an evaluation of our scheme in terms of its performance. The critical parameters for the evaluation of the scheme are the number of users within the multicast group, the amount of data sent to the multicast users, the density of the multicast users within the cells and finally the type of transport channel used for the transmission of the multicast data over the air.10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aAntonellis, Dimitrios uhttp://telematics.upatras.gr/telematics/publications/supporting-group-communication-wcdma-networks?language=el01778nas a2200169 4500008004100000245008300041210006900124260001600193300001500209520115800224653000901382653000901391100002101400700002201421700002301443856014201466 2005 eng d00aA Decision Feedback Scheme for Multimedia Transmission Over 3G Mobile Networks0 aDecision Feedback Scheme for Multimedia Transmission Over 3G Mob c6 - 9 March a 357 - 3613 aUMTS, the successor of GSM, 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 multimedia content. In this paper, we describe the design and the implementation of a decision feedback scheme, which is based on real time protocols and it is used for streaming video over UMTS transport channels. The decision feedback scheme uses a friendly, to the mobile users, congestion control mechanism to control the transmission rate of the real time video sequence. Furthermore, we evaluate this mechanism through a number of experiments. During these experiments we demonstrate the friendly behavior of the decision feedback scheme to TCP and UDP data streams that coexist in the same channel with the video sequence.10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aIgglesis, Vaggelis uhttp://telematics.upatras.gr/telematics/publications/decision-feedback-scheme-multimedia-transmission-over-3g-mobile-networks?language=el01269nas a2200169 4500008004100000245006800041210006800109260001900177300001300196520067300209653000900882653000900891100002100900700002200921700002300943856013300966 2005 eng d00aMultimedia Transmission over Third Generation Cellurar Networks0 aMultimedia Transmission over Third Generation Cellurar Networks c25 - 27 August a 317 3243 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 applies when the user is experiencing real time multimedia content. This paper has as main target to study the performance of video transmission over the third generation cellular networks. In particular, we examine the performance of UMTS Dedicated Channels (DCHs) for real time MPEG-4 video transmission in Downlink direction. Finally, we examine if real time video transmission in conjunction with Internet traffic is applicable in UMTS radio interface.

10aMBMS10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aIgglesis, Vaggelis uhttp://telematics.upatras.gr/telematics/publications/multimedia-transmission-over-third-generation-cellurar-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