TY - JOUR T1 - A study of Forward Error Correction for Mobile Multicast JF - International Journal of Communication Systems, Wiley InterScience Y1 - 2011 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois KW - FEC KW - MBMS KW - Power Control KW - UMTS AB -

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.

ER - TY - JOUR T1 - An Efficient Mechanism for UMTS Multicast Routing JF - Mobile Networks and Applications, Springer Verlang Y1 - 2010 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois KW - MBMS KW - UMTS AB -

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.

VL - 15 ER - TY - JOUR T1 - An Improved Mechanism for Multiple MBMS Sessions Assignment in B3G Cellurar Networks JF - Wireless Networks, Springer Verlang Y1 - 2010 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos A1 - Evangelos Rekkas KW - MBMS KW - Power Control KW - UMTS AB -

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.

VL - 16 IS - 3 ER - TY - CHAP T1 - The Multimedia Broadcast/Multicast Service of the Universal Mobile Telecommunications System T2 - Selected Topics in Communication Networks and Distributed Systems Y1 - 2010 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos A1 - Evangelos Rekkas KW - MBMS KW - UMTS AB -

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.

JF - Selected Topics in Communication Networks and Distributed Systems PB - World Scientific ER - TY - CHAP T1 - Congestion Control for Multicast Transmission over UMTS T2 - Wireless Quality of Service: Techniques, Standards and Applications Y1 - 2009 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois KW - Congestion Control KW - UMTS AB -

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.

JF - Wireless Quality of Service: Techniques, Standards and Applications PB - Auerbach Publications, Taylor & Francis Group ER - TY - JOUR T1 - Cost Analysis and Efficient Radio Bearer Selection for Multicasting over UMTS JF - Wireless Communications and Mobile Computing, Wiley InterScience Y1 - 2009 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos A1 - Evangelos Rekkas KW - Cost analysis KW - MBMS KW - Power Control KW - UMTS AB - Along 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. ER - TY - CONF T1 - An Efficient Mechanism for Power Control Optimization in MBMS Enabled UTRAN T2 - IEEE Wireless Communications and Networking Conference, Budapest, Hungary Y1 - 2009 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos KW - MBMS KW - Power Control KW - UMTS AB - This 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. JF - IEEE Wireless Communications and Networking Conference, Budapest, Hungary ER - TY - CONF T1 - An Enhanced Mechanism for Efficient Assignment of Multiple sessions towards LTE T2 - The 12th ACM Annual Conference on Modeling, Analysis and Simulation of Wireless Mobile Systems, Tenerife, The Canary Islands, Spain Y1 - 2009 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos KW - LTE KW - MBMS KW - Power Control KW - UMTS AB - The 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. JF - The 12th ACM Annual Conference on Modeling, Analysis and Simulation of Wireless Mobile Systems, Tenerife, The Canary Islands, Spain ER - TY - CONF T1 - Optimizing MBMS Power Allocation Through HSDPA Transmissions T2 - The Fifth Advanced International Conference on Telecommunications - AICT 2009, Venice, Italy Y1 - 2009 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Evangelos Rekkas KW - MBMS KW - Power Control KW - UMTS AB - Long 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. JF - The Fifth Advanced International Conference on Telecommunications - AICT 2009, Venice, Italy ER - TY - JOUR T1 - A Study of Multicast Congestion Control for UMTS JF - International Journal of Communication Systems, Wiley InterScience Y1 - 2009 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois KW - Congestion Control KW - MBMS KW - UMTS AB - In this paper, we study the applicability of multicast congestion control over universal mobile telecommunications system (UMTS) networks. We analyze two well-known multicast congestion control schemes for fixed networks, namely TCP-friendly multicast congestion control and pragmatic general multicast congestion control. We investigate their behavior when they are employed in UMTS networks and we analyze the problems arose when these mechanisms are applied over the wireless links of the UMTS terrestrial radio-access network. Additionally, we propose necessary improvements to these legacy schemes and explain the necessity of these modifications. The proposed schemes are implemented in the ns-2 network simulator and are evaluated under various network conditions and topologies. Finally, we measure the performance of the proposed modified schemes and compare them with the corresponding legacy mechanisms. ER - TY - CONF T1 - Balancing between Power Optimization and Iub Efficiency in MBMS enabled UMTS Networks T2 - 1st IFIP Wireless and Mobile Networking Conference (WMNC 2008) , Toulouse, France Y1 - 2008 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos KW - MBMS KW - Power Control KW - UMTS AB - Multicast 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. JF - 1st IFIP Wireless and Mobile Networking Conference (WMNC 2008) , Toulouse, France ER - TY - CONF T1 - Bridging UMTS and Multicast Routing in ns - 2 T2 - First International Conference on Simulation Tools and Techniques for Communications, Networks, and Systems, Marseille, France Y1 - 2008 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois KW - MBMS KW - UMTS AB - In 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. JF - First International Conference on Simulation Tools and Techniques for Communications, Networks, and Systems, Marseille, France ER - TY - CONF T1 - Efficient Assignment of Multiple MBMS Sessions in B3G Networks T2 - 2008 IEEE 68th Vehicular Technology Conference – VTC2008 Fall, Calgary, Canada Y1 - 2008 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos A1 - Evangelos Rekkas KW - MBMS KW - Power Control KW - UMTS AB - 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 running in the network. JF - 2008 IEEE 68th Vehicular Technology Conference – VTC2008 Fall, Calgary, Canada ER - TY - CONF T1 - Efficient Delivery of MBMS Multicast Traffic over HSDPA T2 - Third Workshop on multimedia Applications over Wireless Networks (MediaWiN 2008), Marrakech, Morocco Y1 - 2008 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Evangelos Rekkas KW - MBMS KW - UMTS AB - Multimedia 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. JF - Third Workshop on multimedia Applications over Wireless Networks (MediaWiN 2008), Marrakech, Morocco ER - TY - JOUR T1 - An Efficient Mechanism for Multicast Data Transmission in UMTS JF - Wireless Personal Communications Journal, Spinger Verlang, Vol. 44, No. 4 Y1 - 2008 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Dimitrios Antonellis KW - MBMS KW - UMTS AB - In 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. ER - TY - CONF T1 - Evaluation of Different Radio Bearer Selection Approaches for MBMS in B3G Networks T2 - IFIP Wireless Days Conference 2008, Dubai, United Arab Emirates Y1 - 2008 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos A1 - Evangelos Rekkas KW - MBMS KW - Power Control KW - UMTS AB - The 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. JF - IFIP Wireless Days Conference 2008, Dubai, United Arab Emirates ER - TY - JOUR T1 - Multicast in UMTS: Evaluation and Recommendations JF - Wireless Communications and Mobile Computing, Wiley InterScience, Volume 8, Issue 4 Y1 - 2008 A1 - Christos Bouras A1 - Antonios Alexiou KW - MBMS KW - UMTS AB - It 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. ER - TY - CONF T1 - A Novel Mechanism for Radio Capacity Maximization during MBMS transmission in B3G Networks T2 - The 11th ACM/IEEE International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM 2008), Vancouver, British Columbia, Canada Y1 - 2008 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos A1 - Evangelos Rekkas KW - MBMS KW - Power Control KW - UMTS AB - This 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 provides JF - The 11th ACM/IEEE International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM 2008), Vancouver, British Columbia, Canada ER - TY - CONF T1 - A Novel Power Counting Mechanism for Enhanced MBMS Performance in UMTS Networks T2 - 1st IFIP Wireless and Mobile Networking Conference (WMNC 2008) , Toulouse, France Y1 - 2008 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Evangelos Rekkas KW - MBMS KW - Power Control KW - UMTS AB - One 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. JF - 1st IFIP Wireless and Mobile Networking Conference (WMNC 2008) , Toulouse, France ER - TY - CONF T1 - Power Saving Methods for MBMS Transmissions in UTRAN T2 - The Thirteenth IEEE Symposium on Computers and Communications – ISCC 2008, Marrakech, Morocco Y1 - 2008 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos KW - MBMS KW - Power Control KW - UMTS AB - The 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. JF - The Thirteenth IEEE Symposium on Computers and Communications – ISCC 2008, Marrakech, Morocco ER - TY - JOUR T1 - Adaptive and Reliable Video Transmission over UMTS for Enhanced Performance JF - International Journal of Communication Systems, Wiley InterScience Vol. 20, Issue 1 Y1 - 2007 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Dimitrios Antonellis KW - Congestion Control KW - UMTS AB - This paper proposes a mechanism for the congestion control for video transmission over universal mobile telecommunications system (UMTS). Our scheme is applied when the mobile user experiences real-time multimedia content and adopts the theory of a widely accepted rate control method in wired networks, namely equation-based rate control. In this approach, the transmission rate of the multimedia data is determined as a function of the packet loss rate, the round trip time and the packet size and the server explicitly adjusts its sending rate as a function of these parameters. Furthermore, we examine the performance of the UMTS for real-time video transmission using real-time protocols. Through a number of experiments, we measure performance parameters such as end-to-end delay, delay in radio access network, delay jitter and throughput in the wireless link. ER - TY - Generic T1 - Adaptive Transmission of Multimedia Data over UMTS Y1 - 2007 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Dimitrios Antonellis KW - UMTS JF - Encyclopedia of Mobile Computing & Commerce, Vol. 1, IDEA Group Publishing ER - TY - CONF T1 - On the Applicability of pgmcc to UMTS Multicast T2 - 2007 International Conference on Late Advances in Networks (ICLAN-2007), Paris, France Y1 - 2007 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois KW - Congestion Control KW - UMTS AB - In this paper, we investigate the applicability of the Pragmatic General Multicast Congestion Control (pgmcc) scheme to the multicast data delivery over Universal Mobile Telecommunications System (UMTS) networks. We show that the pgmcc scheme cannot support the degradation of the radio channels in the UMTS Terrestrial Radio-Access Network (UTRAN). Our major contribution is that the legacy scheme is modified in order to cope with the packet losses caused by either the temporary or the permanent degradation of the radio channel. The proposed scheme introduces minor modifications in the UMTS nodes and respects the limited computing power of the mobile equipment. Finally, we simulate our approach and we evaluate it under various conditions. The simulation results are presented along with their analysis JF - 2007 International Conference on Late Advances in Networks (ICLAN-2007), Paris, France ER - TY - CONF T1 - Cost Analysis of the MBMS Multicast Mode of UMTS T2 - The Twelfth IEEE Symposium on Computers and Communications, Aveiro, Portugal Y1 - 2007 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Evangelos Rekkas KW - Cost analysis KW - MBMS KW - UMTS AB - 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). 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. JF - The Twelfth IEEE Symposium on Computers and Communications, Aveiro, Portugal ER - TY - CONF T1 - An efficient mechanism for adaptive multimedia transmission in 3G networks T2 - IADIS International Conference Wireless Applications and Computing 2007, Lisbon, Portugal Y1 - 2007 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Konstantinos Barounis KW - UMTS AB - This 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. JF - IADIS International Conference Wireless Applications and Computing 2007, Lisbon, Portugal ER - TY - CONF T1 - Evaluation of the multicast mode of MBMS T2 - 18th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Athens, Greece Y1 - 2007 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos A1 - Evangelos Rekkas KW - MBMS KW - UMTS AB - Multicasting 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. JF - 18th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Athens, Greece ER - TY - CONF T1 - MBMS Power Planning in Macro and Micro Cell Envirohments T2 - Second IEEE Workshop on multimedia Applications over Wireless Networks(MediaWiN 2007), Aveiro, Portugal Y1 - 2007 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos A1 - Evangelos Rekkas KW - MBMS KW - Power Control KW - UMTS AB - Multimedia 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. JF - Second IEEE Workshop on multimedia Applications over Wireless Networks(MediaWiN 2007), Aveiro, Portugal ER - TY - CONF T1 - Multicast in UMTS: Adopting TCP - Friendliness T2 - Personal Wireless Communications (PWC07) - 12th IFIP International Conference, Prague, Czech Republic Y1 - 2007 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois KW - MBMS KW - UMTS AB - In 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. JF - Personal Wireless Communications (PWC07) - 12th IFIP International Conference, Prague, Czech Republic ER - TY - CONF T1 - A Power Control Scheme for Efficient Radio Bearer Selection in MBMS T2 - 8th International Symposium on a World of Wireless, Mobile and Multimedia Networks, - WoWMoM 2007, Helsinki, Finland Y1 - 2007 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Evangelos Rekkas KW - MBMS KW - Power Control KW - UMTS AB - This 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. JF - 8th International Symposium on a World of Wireless, Mobile and Multimedia Networks, - WoWMoM 2007, Helsinki, Finland ER - TY - CONF T1 - Power Efficient Radio Bearer Selection in MBMS Multicast Mode T2 - 10th ACM - IEEE International Symposium on Modeling, Analysis and Simulation of Wireless and Mobile Systems - MSWIM 2007, Chania, Crete, Greece Y1 - 2007 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos A1 - Evangelos Rekkas KW - MBMS KW - Power Control KW - UMTS AB - Multimedia 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. JF - 10th ACM - IEEE International Symposium on Modeling, Analysis and Simulation of Wireless and Mobile Systems - MSWIM 2007, Chania, Crete, Greece ER - TY - CONF T1 - Power Saving Techniques in MBMS Multicast Mode T2 - 3rd ACM International Workshop on Wireless Multimedia Networking and Performance Modeling - ACM WMUNEP 2007, Chania, Crete, Greece, Y1 - 2007 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos KW - MBMS KW - Power Control KW - UMTS AB - 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 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. JF - 3rd ACM International Workshop on Wireless Multimedia Networking and Performance Modeling - ACM WMUNEP 2007, Chania, Crete, Greece, ER - TY - JOUR T1 - Scalable Rate Control for Video Transmission over UMTS JF - International Journal of Communication Systems, Wiley InterScience, Vol. 20, Issue 12 Y1 - 2007 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vaggelis Igglesis KW - Congestion Control KW - UMTS AB - This paper proposes a mechanism for the congestion control for video transmission over Universal Mobile Telecommunications System (UMTS). Our scheme is applied when the mobile user experiences real time multimedia content and adopts the theory of a widely accepted rate control method in wired networks, namely equation-based rate control. In this approach, the transmission rate of the multimedia data is determined as a function of the packet loss rate, the round trip time and the packet size and the server explicitly adjusts its sending rate as a function of these parameters. Through a number of simulations and experiments we validate the correctness and measure the 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. ER - TY - CONF T1 - An Efficient Multicast Packet Delivery Scheme for UMTS T2 - 9th ACM International Symposium on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM 2006), Torremolinos, Spain Y1 - 2006 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Dimitrios Antonellis A1 - Andreas Papazois KW - MBMS KW - UMTS AB - In 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 procedure JF - 9th ACM International Symposium on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM 2006), Torremolinos, Spain ER - TY - CONF T1 - Equation Based Congestion Control for Video Transmission over WCDMA Networks T2 - The IEEE 20th International Conference on Advanced Information Networking and Applications, Vienna, Austria Y1 - 2006 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Dimitrios Antonellis KW - Congestion Control KW - UMTS AB - 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. JF - The IEEE 20th International Conference on Advanced Information Networking and Applications, Vienna, Austria ER - TY - CONF T1 - Evaluating Different One to Many Packet Delivery Schemes for UMTS T2 - 7th IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks - WoWMoM 2006, Niagara - Falls/Buffalo, New York, USA Y1 - 2006 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Dimitrios Antonellis KW - MBMS KW - UMTS AB - It 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. JF - 7th IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks - WoWMoM 2006, Niagara - Falls/Buffalo, New York, USA ER - TY - CONF T1 - A Multicast Approach for UMTS: A Performance Study T2 - 2006 IFIP Networking Conference, Coimbra, Portugal Y1 - 2006 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Dimitrios Antonellis KW - MBMS KW - UMTS AB - In 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. JF - 2006 IFIP Networking Conference, Coimbra, Portugal ER - TY - CONF T1 - A Multicast Packet Forwarding Mechanism for WCDMA Networks using Routing Lists T2 - 2nd ACM Workshop on Wireless Multimedia Networking and Performance Modeling, (ACM WMuNeP 2006), MSWiM 2006 Workshops, Torremolinos, Malaga, Spain Y1 - 2006 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Dimitrios Antonellis KW - MBMS KW - UMTS AB - This 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. JF - 2nd ACM Workshop on Wireless Multimedia Networking and Performance Modeling, (ACM WMuNeP 2006), MSWiM 2006 Workshops, Torremolinos, Malaga, Spain ER - TY - CONF T1 - Supporting Group Communication in WCDMA Networks T2 - 11th IFIP International Conference on Personal Wireless Communications (PWC '06), Albacete, Spain Y1 - 2006 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Dimitrios Antonellis KW - MBMS KW - UMTS AB - It 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. JF - 11th IFIP International Conference on Personal Wireless Communications (PWC '06), Albacete, Spain ER - TY - CONF T1 - A Decision Feedback Scheme for Multimedia Transmission Over 3G Mobile Networks T2 - The Second IEEE and IFIP International Conference on Wireless and Optical Communications Networks (WOCN 2005), Dubai, United Arab Emirates - UAE Y1 - 2005 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vaggelis Igglesis KW - MBMS KW - UMTS AB - UMTS, 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. JF - The Second IEEE and IFIP International Conference on Wireless and Optical Communications Networks (WOCN 2005), Dubai, United Arab Emirates - UAE ER - TY - CONF T1 - Multimedia Transmission over Third Generation Cellurar Networks T2 - 10th IFIP International Conference on Personal Wireless Communications - PWC'05, Colmar, France Y1 - 2005 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vaggelis Igglesis KW - MBMS KW - UMTS AB -

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.

JF - 10th IFIP International Conference on Personal Wireless Communications - PWC'05, Colmar, France ER - TY - CONF T1 - Rate and Loss Control for Video transmission over UMTS using Real -Time Protocols T2 - 13th Annual Meeting of the IEEE/ACM International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS 2005), Atlanta, Georgia, USA Y1 - 2005 A1 - Christos Bouras A1 - Antonios Alexiou KW - Congestion Control KW - MBMS KW - UMTS AB - UMTS is evolving toward a future wireless all-IP network. In this paper we present how it supports real-time IP multimedia services, as these services are expected to drive the adoption of wireless all-IP networks. The scheme of real time streaming video is one of the newcomers in wireless data communication and in particular in UMTS, raising a number of novel requirements in both telecommunication and data communication systems. This scheme applies when the mobile user is experiencing real time video content. In this work we focus on the design and implementation of a rate and loss control mechanism for monitoring the UMTS network state and estimating the appropriate rate of the streaming video data. JF - 13th Annual Meeting of the IEEE/ACM International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS 2005), Atlanta, Georgia, USA ER - TY - CONF T1 - Performance Evaluation of TCP over UMTS Transport Channels T2 - 7th International Symposium on Communications Interworking - INTERWORKING 2004, Ottawa, Canada Y1 - 2004 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vaggelis Igglesis KW - UMTS AB - Universal 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. JF - 7th International Symposium on Communications Interworking - INTERWORKING 2004, Ottawa, Canada ER - TY - CONF T1 - Performance Evaluation of UMTS for Mobile Internet Access T2 - 12th Annual Meeting of the IEEE/ACM International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS 2004), Volendam, The Netherlands Y1 - 2004 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vaggelis Igglesis KW - UMTS AB - UMTS 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. JF - 12th Annual Meeting of the IEEE/ACM International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS 2004), Volendam, The Netherlands ER -