01536nas a2200181 4500008004100000245006100041210005900102300001500161520096400176653000801140653000901148653001801157653000901175100002101184700002201205700002201227856010501249 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-multicast01565nas a2200169 4500008004100000245005400041210005100095300001400146490000700160520104500167653000901212653000901221100002101230700002201251700002201273856010001295 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-routing01961nas a2200193 4500008004100000245008900041210006900130300001500199490000700214520128900221653000901510653001801519653000901537100002101546700002201567700002401589700002201613856013201635 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-networks01694nas a2200181 4500008004100000245009700041210006900138260002100207300001300228520102600241653000901267653000901276100002101285700002201306700002401328700002201352856013801374 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-system01857nas a2200169 4500008004100000245006000041210006000101260005000161300001500211520125500226653002301481653000901504100002101513700002201534700002201556856010901578 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

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.

10aCongestion Control10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aPapazois, Andreas uhttp://telematics.upatras.gr/telematics/publications/congestion-control-multicast-transmission-over-umts01762nas a2200193 4500008004100000245008200041210006900123300001700192520108500209653001801294653000901312653001801321653000901339100002101348700002201369700002401391700002201415856013101437 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-umts01484nas a2200181 4500008004100000245008000041210006900121260001600190300001800206520085200224653000901076653001801085653000901103100002101112700002201133700002401155856012301179 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-utran01919nas a2200193 4500008004100000245008400041210006900125260002000194300001500214520125800229653000801487653000901495653001801504653000901522100002101531700002201552700002401574856012701598 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-lte01670nas a2200181 4500008004100000245006500041210006500106260001600171300001500187520106700202653000901269653001801278653000901296100002101305700002201326700002201348856011801370 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-transmissions01452nas a2200169 4500008004100000245005300041210005100094300001500145520091900160653002301079653000901102653000901111100002101120700002201141700002201163856009701185 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-umts01531nas a2200181 4500008004100000245009000041210006900131260001800200300001500218520087300233653000901106653001801115653000901133100002101142700002201163700002401185856014001209 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-networks01410nas a2200157 4500008004100000245005000041210004800091260001600139520091600155653000901071653000901080100002101089700002201110700002201132856009801154 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-201720nas a2200193 4500008004100000245006700041210006700108260002100175300001100196520108000207653000901287653001801296653000901314100002101323700002201344700002401366700002201390856011401412 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-networks01517nas a2200169 4500008004100000245006000041210006000101260001100161300001300172520096900185653000901154653000901163100002101172700002201193700002201215856011001237 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-hsdpa01412nas a2200157 4500008004100000245006700041210006400108300001500172520087000187653000901057653000901066100002101075700002201096700002601118856011001144 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-umts01778nas a2200181 4500008004100000245008700041210006900128260002100197520112300218653000901341653001801350653000901368100002101377700002201398700002401420700002201444856013001466 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-networks01468nas a2200145 4500008004100000245005400041210005300095300001400148520099600162653000901158653000901167100002101176700002201197856010301219 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-recommendations01908nas a2200193 4500008004100000245009500041210006900136260002000205300001500225520121000240653000901450653001801459653000901477100002101486700002201507700002401529700002201553856013901575 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-networks01790nas a2200181 4500008004100000245008400041210006900125260002900194300001300223520114300236653000901379653001801388653000901406100002101415700002201436700002201458856012801480 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-networks01810nas a2200181 4500008004100000245005700041210005700098260001500155300001500170520123700185653000901422653001801431653000901449100002101458700002201479700002401501856010301525 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-utran01463nas a2200157 4500008004100000245008000041210006900121300001300190520087200203653002301075653000901098100002101107700002201128700002601150856012901176 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-performance00481nas a2200133 4500008004100000245005500041210005500096300001300151653000900164100002100173700002200194700002600216856010500242 2007 eng d00aAdaptive Transmission of Multimedia Data over UMTS0 aAdaptive Transmission of Multimedia Data over UMTS a 20 - 2410aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aAntonellis, Dimitrios uhttp://telematics.upatras.gr/telematics/publications/adaptive-transmission-multimedia-data-over-umts01343nas a2200169 4500008004100000245005200041210004500093260001900138300001300157520081400170653002300984653000901007100002101016700002201037700002201059856009201081 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-multicast01471nas a2200181 4500008004100000245005300041210005300094260001500147300001500162520091500177653001801092653000901110653000901119100002101128700002201149700002201171856009601193 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-umts01555nas a2200157 4500008004100000245007900041210006900120260001500189300001300204520097900217653000901196100002101205700002201226700002701248856012201275 2007 eng d00aAn efficient mechanism for adaptive multimedia transmission in 3G networks0 aefficient mechanism for adaptive multimedia transmission in 3G n c3 - 8 July a 11 - 183 aThis paper proposes a mechanism for the congestion control for video transmission over Universal Mobile Telecommu-nications 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. The mechanism at first level is evaluated through simulations that carried out in the ns-2 simulator. At sec-ond level, in order to validate the proposed mechanism in real world traffic scenar-ios we perform some experiments in a commercial UMTS network.10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aBarounis, Konstantinos uhttp://telematics.upatras.gr/telematics/publications/efficient-mechanism-adaptive-multimedia-transmission-3g-networks01611nas a2200169 4500008004100000245004500041210004500086260002000131520109500151653000901246653000901255100002101264700002201285700002401307700002201331856008801353 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-mbms01575nas a2200193 4500008004100000245006100041210006100102260001100163300001300174520095800187653000901145653001801154653000901172100002101181700002201202700002401224700002201248856011101270 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-envirohments01189nas a2200169 4500008004100000245005100041210004800092260002200140300001500162520066100177653000900838653000900847100002100856700002200877700002200899856009800921 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-friendliness01399nas a2200181 4500008004100000245007200041210006900113260001700182300001100199520079000210653000901000653001801009653000901027100002101036700002201057700002201079856011601101 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-mbms01863nas a2200193 4500008004100000245006600041210006600107260002000173300001500193520122000208653000901428653001801437653000901455100002101464700002201485700002401507700002201531856011601553 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-mode01677nas a2200181 4500008004100000245005100041210005100092260001500143300001300158520112000171653000901291653001801300653000901318100002101327700002201348700002401370856010101394 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-mode01473nas a2200157 4500008004100000245005900041210005900100300001700159520093300176653002301109653000901132100002101141700002201162700002301184856010801207 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-umts01314nas a2200169 4500008004100000245005900041210005600100260001600156520075800172653000900930653000900939100002100948700002200969700002600991700002201017856010501039 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-umts01530nas a2200169 4500008004100000245008100041210006900122260001800191300001500209520090500224653002301129653000901152100002101161700002201182700002601204856013001230 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-networks01268nas a2200169 4500008004100000245007000041210006900111260001700180300001100197520068700208653000900895653000900904100002100913700002200934700002600956856011600982 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-umts01225nas a2200169 4500008004100000245005500041210005200096260001600148300001500164520069000179653000900869653000900878100002100887700002200908700002600930856009900956 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-study01717nas a2200169 4500008004100000245008300041210006900124260001400193300001300207520111000220653000901330653000901339100002101348700002201369700002601391856013001417 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-lists01658nas a2200169 4500008004100000245005300041210005300094260002200147300001300169520111600182653000901298653000901307100002101316700002201337700002601359856010301385 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-networks01766nas a2200169 4500008004100000245008300041210006900124260001600193300001500209520115800224653000901382653000901391100002101400700002201421700002301443856013001466 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-networks01257nas a2200169 4500008004100000245006800041210006800109260001900177300001300196520067300209653000900882653000900891100002100900700002200921700002300943856012100966 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-networks01336nas a2200169 4500008004100000245008600041210006900127260002200196300001500218520071500233653002300948653000900971653000900980100002100989700002201010856013401032 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-protocols01550nas a2200145 4500008004100000245006300041210006300104260002900167520102000196653000901216100002101225700002201246700002301268856011301291 2004 eng d00aPerformance Evaluation of TCP over UMTS Transport Channels0 aPerformance Evaluation of TCP over UMTS Transport Channels c29 November - 1 December3 aUniversal Mobile Telecommunications System (UMTS) is a third-generation cellular network that enables high-speed wireless Internet access. It can provide maximum data-rates ranging from 64kb/s to 2Mb/s in different environmental types. UMTS is designed to provide access to the existing Internet services as well as to UMTS specific services. It will augment the existing capabilities of 2G mobile networks and GPRS, and one often envisaged strategy is to offer a richer set of multimedia services. It is widely known that TCP does not perform efficiently in wireless links where the bit error rate is high enough. This paper has as main target to evaluate the performance of TCP data transfer over the UMTS air interface, by means of a rather detailed simulation model. We examine the performance of TCP over UMTS Dedicated Channels (DCHs) with different bit rates and Transmission Time Intervals (TTIs) and we represent some simulation experiments for UMTS High Speed Downlink Packet Access (HSDPA) transmissions.10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aIgglesis, Vaggelis uhttp://telematics.upatras.gr/telematics/publications/performance-evaluation-tcp-over-umts-transport-channels01226nas a2200157 4500008004100000245006200041210006200103260001800165300001100183520069100194653000900885100002100894700002200915700002300937856010800960 2004 eng d00aPerformance Evaluation of UMTS for Mobile Internet Access0 aPerformance Evaluation of UMTS for Mobile Internet Access c5 - 7 October a 1 - 43 aUMTS constitutes the third generation of cellular wireless networks which aims to provide high-speed data access along with real time voice calls (Holma & Toskala, 2001). Wireless data is one of the major boosters of wireless communications and one of the main challenges of next generation standards (Chaudhury & Mohr, 1999). It can provide maximum data-rates ranging from 64kb/s to 2Mb/s in different environmental types. UMTS is designed to provide access to the existing Internet services as well as to UMTS specific services. It will augment the existing capabilities of 2G mobile networks and GPRS, and one often envisaged strategy is to offer a richer set of multimedia services.10aUMTS1 aBouras, Christos1 aAlexiou, Antonios1 aIgglesis, Vaggelis uhttp://telematics.upatras.gr/telematics/publications/performance-evaluation-umts-mobile-internet-access