TY - JOUR T1 - Application Layer Forward Error Correction for Multicast Streaming over LTE Networks JF - International Journal of Communication Systems, Wiley InterScience Y1 - 2013 A1 - Christos Bouras A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - Nikos Kanakis KW - FEC KW - LTE KW - MBMS AB -

The next step beyond third generation (3G) mobile networks is the Third Generation Partnership Project (3GPP) standard, named Long Term Evolution (LTE). A key feature of LTE is the enhancement of Multimedia Broadcast/Multicast Services (MBMS), where the same content is transmitted to multiple users located in a specific service area. To support efficient download and streaming delivery, 3GPP included an application layer Forward Error Correction (AL-FEC) technique based on the systematic fountain Raptor code, in the MBMS standard. In order to achieve protection against packet losses, Raptor codes introduce redundant packets to the transmission, i.e., the FEC overhead. In this work, we investigate the application of AL-FEC over MBMS streaming services. We consider the benefits of AL-FEC for a continuous multimedia stream transmission to multiple users and we examine how the amount of FEC redundancy can be adjusted under different packet loss conditions. For this purpose, we present a variety of realistic simulation scenarios for the application of AL-FEC and furthermore we provide an in-depth analysis of Raptor codes performance introducing valuable suggestions to achieve efficient use of Raptor codes.

VL - 26 ER - TY - JOUR T1 - Embracing RaptorQ FEC in 3GPP multicast services JF - Wireless Networks, Springer Verlang Y1 - 2013 A1 - Christos Bouras A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - Nikos Kanakis KW - FEC KW - MBMS AB -

Multimedia Broadcast/Multicast Services (MBMS) have been introduced by Third Generation Partnership Project (3GPP) aiming to efficiently deliver data to mobile users in a one-to-many way. In order to provide reliable multicast transmission, 3GPP recommends exclusively for MBMS the use of a Forward Error Correction (FEC) mechanism on the application layer. Raptor codes are standardized as the Application Layer FEC (AL-FEC) scheme over 3GPP MBMS. However, the 3GPP standardized systematic fountain Raptor code is nowadays considered obsolete, since a new variation of the Raptor codes has emerged. This enhanced AL-FEC scheme, named RaptorQ, promises higher protection efficiency and superior flexibility on the provision of demanding mobile multicast services. In this work, we provide an extensive performance evaluation presenting at first a theoretical performance comparison of the newly introduced RaptorQ FEC scheme with its predecessor Raptor code, examining the enhancements that RaptorQ introduces on the AL-FEC protection robustness. Thereafter, to verify the enhanced performance of RaptorQ, we present several simulation results considering the modeling of the AL-FEC protection over multicast services for next generation mobile networks, utilizing the ns-3 simulation environment. Investigating several mobile system parameters in conjunction with FEC encoding parameters, we provide valuable results regarding the impacts of the examined AL-FEC schemes application on the multicast services performance.

VL - 19 IS - 5 ER - TY - CONF T1 - Enhaning Reliable Mobile Multicasting with RaptorQ FEC T2 - 17th IEEE Symposium on Computers andCommunication (ISCC), Cappadocia, Turkey Y1 - 2012 A1 - Christos Bouras A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - Nikos Kanakis KW - FEC KW - LTE KW - MBMS AB - A crucial point on the successful deployment of multicast services is the enhanced reliability by means of advanced error control schemes. To this direction Third Generation Partnership Project (3GPP) has standardized exclusively for Multimedia Broadcast/Multicast Services (MBMS) the use of a Forward Error Correction (FEC) mechanism on the application layer based on Raptor codes. Since the standardized systematic, fountain Raptor code is now considered obsolete, the emergence of a new variant of Raptor codes, named RaptorQ, provides enhanced capabilities for mobile multicast services. In this paper, we provide a performance comparison of the standardized Raptor Application Layer FEC (AL-FEC) scheme with the very promising RaptorQ FEC code. We examine the enhancements that RaptorQ introduces on the AL-FEC protection robustness, providing a thorough performance analysis in comparison with the current Raptor FEC scheme. Furthermore, in order to verify the improved performance of RaptorQ, we provide several simulation results utilizing the ns-3 environment, considering the application of both the examined AL-FEC schemes over multicast services for next generation mobile networks. JF - 17th IEEE Symposium on Computers andCommunication (ISCC), Cappadocia, Turkey ER - TY - CONF T1 - Evaluating RaptorQ FEC over 3GPP Multicast Services T2 - The 8th International Wireless Communications & Mobile Computing Conference (IWCMC 2012), Limassol, Cyprus Y1 - 2012 A1 - Christos Bouras A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - Nikos Kanakis KW - FEC KW - LTE KW - MBMS AB - Third Generation Partnership Project (3GPP) introduced Multimedia Broadcast/Multicast Services (MBMS), in order to efficiently deliver the same content to multiple users over mobile cellular networks. To enhance the download and streaming delivery robustness against packet losses, 3GPP proposes the use of Forward Error Correction (FEC) on the application layer. The Application Layer FEC (AL-FEC) scheme that 3GPP standardized is based on the systematic, fountain Raptor code. In this work, in response to the emergence of an enhanced FEC scheme, we provide a performance evaluation of the existing standardized AL-FEC scheme with the newly introduced RaptorQ code. Introducing a variety of simulation experiments, we analyze the performance behavior of each AL-FEC scheme considering several FEC encoding parameters. Furthermore, we try to verify the improvements that have emerged in AL-FEC providing enhanced capabilities in multicast services over next generation mobile networks. JF - The 8th International Wireless Communications & Mobile Computing Conference (IWCMC 2012), Limassol, Cyprus ER - TY - CONF T1 - Genetic Optimization for Spectral Efficient Multicasting in LTE Systems T2 - Fifth IFIP Wireless and Mobile Networking Conference, Bratislava, Slovakia Y1 - 2012 A1 - Christos Bouras A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - Konstantinos Asimakis KW - LTE KW - MBMS KW - MBSFN AB -

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

JF - Fifth IFIP Wireless and Mobile Networking Conference, Bratislava, Slovakia ER - TY - CHAP T1 - Multimedia Broadcasting in LTE Networks T2 - Access Environments and Quality of Service Provisioning: Solutions and Applications Y1 - 2012 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - George Tsichritzis KW - LTE KW - MBMS AB -

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

JF - Access Environments and Quality of Service Provisioning: Solutions and Applications PB - IGI Global ER - TY - CONF T1 - AL-FEC for Streaming Services over LTE Systems T2 - 14th International Symposiumon Wireless Personal Multimedia Communications, Brest, France Y1 - 2011 A1 - Christos Bouras A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - Nikos Kanakis KW - FEC KW - LTE KW - MBMS AB -

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

JF - 14th International Symposiumon Wireless Personal Multimedia Communications, Brest, France ER - TY - CONF T1 - Combining MBSFN and PTM Transmissions Schemes for Resource Efficiency in LTE Networks T2 - 9th International Conference on Wired/Wireless Internet Communications, Vilanova I la Geltru, Barcelona, Spain, June 15 - 17, 2011 Y1 - 2011 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - Konstantinos Asimakis KW - LTE KW - MBMS KW - MBSFN AB - Long Term Evolution (LTE) systems allow the transmission of rich multimedia services by utilizing the Multimedia Broadcast/Multicast Service (MBMS) over a Single Frequency Network (MBSFN). During MBSFN transmission a time-synchronized common waveform is transmitted from multiple cells. The 3rd Generation Partnership Project (3GPP) has specified that Point-to-Multipoint (PTM) transmission can be used in combination with MBSFN to provide MBMS-based services. In this paper we evaluate the combined transmission scheme in terms of Resource Efficiency (RE). The evaluation is performed through simulation experiments for various user distributions and LTE network configurations. The experiments are conducted with the aid of a proposed algorithm, which estimates the Spectral Efficiency (SE) of each cell and the RE of the network, and is also able to formulate the optimal network deployment that maximizes the network?s RE. For each of the examined scenarios, we present the most efficient solution (in terms of RE) selected by our algorithm and we compare it with other transmission schemes. JF - 9th International Conference on Wired/Wireless Internet Communications, Vilanova I la Geltru, Barcelona, Spain, June 15 - 17, 2011 ER - TY - CHAP T1 - Forward Error Correction for Reliable e-MBMS Transmissions in LTE Networks T2 - Cellurar Networks Y1 - 2011 A1 - Christos Bouras A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - Georgia Tseliou KW - FEC KW - LTE KW - MBMS JF - Cellurar Networks PB - InTech ER - TY - CONF T1 - Optimizing the Combination of MBSFN and PTM Transmissions in LTE Systems T2 - Tenth Annual Wireless Telecommunications Symposium (WTS 2011), New York, USA Y1 - 2011 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - Georgia Tseliou KW - LTE KW - MBMS KW - MBSFN AB - The 3rd Generation Partnership Project (3GPP) has introduced the evolved Multimedia Broadcast/Multicast Service (e-MBMS) feature for cellular systems as an evolution to the existing MBMS service. To support e-MBMS in Long Term Evolution (LTE) systems, 3GPP recommends the use of Point-to- Multipoint (PTM) transmissions and MBMS over a Single Frequency Network (MBSFN). MBSFN is a new feature where a time-synchronized common waveform is transmitted from multiple cells. In this paper we investigate the provision of MBMS service over a combination of MBSFN and PTM transmission methods. A cost analysis of the MBMS service is presented based on the transmission cost over all the interfaces and nodes of the LTE architecture. We evaluate the performance of this transmission scheme from telecommunication cost perspective and we compare it with other transmission schemes. The performance evaluation has been performed with the aid of a new simulation tool that estimates the cost for the MBMS provision under different network topologies, MBSFN deployments and user distributions. JF - Tenth Annual Wireless Telecommunications Symposium (WTS 2011), New York, USA ER - TY - CONF T1 - Reliable Multicasting over LTE: A Performance Study T2 - 16th IEEE Symposioum on Computers and Communications (ISCC 2011), Kerkyra, Greece Y1 - 2011 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - Konstantinos Asimakis A1 - Georgia Tseliou KW - FEC KW - LTE KW - MBMS KW - MBSFN AB - With the booming of multimedia services, the 3rd Generation Partnership Project (3GPP) has introduced the evolved Multimedia Multicast/Broadcast Service (e-MBMS) feature for LTE systems. The main objective of MBMS is to introduce real broadcast distribution capabilities into cellular systems. This purposed 3GPP to introduce the MBMS over a Single Frequency Network (MBSFN) operation. In this work we investigate the provision of MBMS service over a combination of MBSFN and PTM transmission schemes. We focus on the file repair procedure, because the distribution of binary data via MBMS must result in 100% error-free downloaded files. In order to achieve this goal, MBMS offers a Forward Error Correction (FEC) mechanism. Our simulation results show that there are some file repair schemes that achieve better performance as far as different network configurations are concerned. Furthermore, we compare all the file recovery methods and evaluate them against various network parameters in a realistic simulation environment. JF - 16th IEEE Symposioum on Computers and Communications (ISCC 2011), Kerkyra, Greece ER - 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 - CONF T1 - Adopting FEC for Reliable Multicasting over LTE Networks T2 - 13th ACM International Conference on Modeling Analysis and Simulation of Wireless and Mobile Systems, Bodrum, Turkey Y1 - 2010 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - George Tsichritzis KW - FEC KW - LTE KW - MBMS AB - The key feature for the provision of Multimedia Broadcast/Multicast Services (MBMS) in Long Term Evolution (LTE) networks is the Multimedia Broadcast over a Single Frequency Network (MBSFN). On the other hand, the use of Forward Error Correction (FEC) in mobile multicast transmission has significant advantages and the 3rd Generation Partnership Project (3GPP) has adopted the application layer FEC in the MBMS standard. In this paper, we investigate the impact of the application layer FEC over the MBSFN delivery method. JF - 13th ACM International Conference on Modeling Analysis and Simulation of Wireless and Mobile Systems, Bodrum, Turkey ER - TY - CONF T1 - Adopting forward error correction for multicasting over cellurar networks T2 - European Wireless 2010, Lucca, Italy Y1 - 2010 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois KW - FEC KW - LTE KW - MBMS KW - MBSFN AB -

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

JF - European Wireless 2010, Lucca, Italy ER - TY - CONF T1 - Efficient MCS Selection for MBSFN Transmissions over LTE Networks T2 - IFIP Wireless Days 2010, Venice, Italy Y1 - 2010 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - George Tsichritzis KW - LTE KW - MBMS KW - MBSFN KW - MCS AB - Long Term Evolution (LTE), the next-generation network beyond 3G, is designed to support the explosion in demand for bandwidth-hungry multimedia services that are already experienced in wired networks. To support Multimedia Broadcast/Multicast Services (MBMS), LTE offers functionality to transmit MBMS over a Single Frequency Network (MBSFN), where a time-synchronized common waveform is transmitted from multiple cells for a given duration. This significantly improves the Spectral Efficiency (SE) compared to conventional MBMS operation. The achieved SE is mainly determined by the Modulation and Coding Scheme (MCS) utilized by the LTE physical layer. In this paper we propose and evaluate four approaches for the selection of the MCS that will be utilized for the transmission of the MBSFN data. The evaluation of the approaches is performed for different users? distribution and from SE perspective. Based on the SE measurement, we determine the most suitable approach for the corresponding users? distribution. JF - IFIP Wireless Days 2010, Venice, Italy 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 - CHAP T1 - Efficient Power Allocation in E-MBMS Enabled 4G Networks T2 - Wireless Network Traffic and Quality of Service Support: Trends and Standards Y1 - 2010 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos KW - LTE KW - MBMS KW - Power Control AB -

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

JF - Wireless Network Traffic and Quality of Service Support: Trends and Standards PB - IGI Global ER - TY - CONF T1 - Enhancing FEC Application in LTE Cellular Networks T2 - IFIP Wireless Days 2010, Venice, Italy Y1 - 2010 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - Georgia Tseliou KW - FEC KW - LTE KW - MBMS KW - MBSFN AB - 3rd Generation Partnership Project?s (3GPP) Long Term Evolution (LTE) is focused on enhancing the Universal Terrestrial Radio Access (UTRA). Evolved-Multimedia Broadcast and Multicast Service (e-MBMS) uses Multimedia Broadcast over a Single Frequency Network (MBSFN) operation in order to improve its performance. In MBSFN operation, data are transmitted simultaneously over the air from multiple tightly time-synchronized cells. Raptor codes have been standardized as the main application layer Forward Error Correction (FEC) method for e-MBMS due to the advanced error protection they offer and their overall performance. In this study, we investigate the application of FEC in MBSFN-enabled LTE cellular networks and we propose a new scheme that takes into account the properties of MBSFN in order to provide a more efficient operation of FEC during e-MBMS transmissions. The proposed scheme is compared with other file recovery methods and is evaluated against various network parameters in a realistic simulation environment. JF - IFIP Wireless Days 2010, Venice, Italy ER - TY - CONF T1 - The Impact of FEC on Mobile Multicast Power Control T2 - The Sixth Advanced International Conference on Telecommunications (AICT 2010), Barcelona, Spain Y1 - 2010 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois KW - FEC KW - LTE KW - MBMS KW - Power Control AB - 3GPP has standardized the use of forward error correction for the provision of reliable data transmission in the mobile multicast framework. In this paper we present a study of the impact of application layer forward error correction on power control during mobile multicast transmission. The evaluation is performed with the aid of a novel scheme that allows the simulation of FEC impact on both streaming delivery and download delivery over a multicast session. It is important that the proposed scheme incorporates the properties of an evolved mobile network, as they are determined by the 3GPP specifications. JF - The Sixth Advanced International Conference on Telecommunications (AICT 2010), Barcelona, Spain ER - TY - JOUR T1 - An Improved MBMS Power Counting Mechanism towards Long Term Evolution JF - Telecommunication Systems Journal, Springer Verlang Y1 - 2010 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Evangelos Rekkas KW - LTE KW - MBMS KW - Power Control AB -

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

VL - 43 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 - Radio Resource Management for E-MBMS Transmissions towards LTE T2 - Evolved Cellular Network Planning and Optimization for UMTS and LTE Y1 - 2010 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos KW - LTE KW - MBMS KW - Power Control AB -

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

JF - Evolved Cellular Network Planning and Optimization for UMTS and LTE PB - Auerbach Publications, CRC Press, Taylor and Francis Group ER - TY - CONF T1 - Spectral Efficiency Performance of MBSFN-enabled LTE Networks T2 - 6th IEEE International Conference on Wireless and Mobile Computing, Networking and Communication (WiMob 2010), Niagara Falls, Canada Y1 - 2010 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Andreas Papazois A1 - Vasileios Kokkinos A1 - George Tsichritzis KW - LTE KW - MBMS KW - MBSFN KW - MCS AB - Long Term Evolution (LTE) constitutes the latest step before the 4th generation (4G) of radio technologies designed to increase the capacity and speed of mobile communications. To support Multimedia Broadcast/Multicast Services (MBMS), LTE offers the possibility to transmit Multimedia Broadcast multicast service over a Single Frequency Network (MBSFN), where a time-synchronized common waveform is transmitted from multiple cells for a given duration. This enables over-the-air combining, thus improving the Signal to Interference plus Noise Ratio (SINR) and spectral efficiency (SE) significantly compared to conventional MBMS operation. In this paper, we analytically calculate the SE performance achieved in a MBSFN area for a dynamically changing user topology and different modulation and coding schemes (MCS). Finally, based on the SE measurement, we determine the MCS scheme that either maximizes or achieves a target SE for the corresponding user distribution. JF - 6th IEEE International Conference on Wireless and Mobile Computing, Networking and Communication (WiMob 2010), Niagara Falls, Canada 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 - Efficient Assignment of Multiple E-MBMS Sessions toward LTE T2 - Second Joint IFIP Wireless and Mobile Networking Conference, Gdansk, Poland Y1 - 2009 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos KW - LTE KW - MBMS AB - One of the major prerequisites for Long Term Evolution (LTE) networks is the mass provision of multimedia services to mobile users. To this end, Evolved - Multimedia Broadcast/Multicast Service (E-MBMS) is envisaged to play an instrumental role during LTE standardization process and ensure LTE?s proliferation in mobile market. E-MBMS targets at the economic delivery, in terms of power and spectral efficiency, of multimedia data from a single source entity to multiple destinations. This paper proposes a novel mechanism for efficient radio bearer selection during E-MBMS transmissions in LTE networks. The proposed mechanism is based on the concept of transport channels combination in any cell of the network. Most significantly, the mechanism manages to efficiently deliver multiple E-MBMS sessions. The performance of the proposed mechanism is evaluated and compared with several radio bearer selection mechanisms in order to highlight the enhancements that it provides. JF - Second Joint IFIP Wireless and Mobile Networking Conference, Gdansk, Poland 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 MBMS Power Control Mechanism towards Long Term Evolution T2 - Eighth Annual Wireless Telecommunications Symposium - WTS 2009, Prague, Czech Republic Y1 - 2009 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos KW - LTE KW - MBMS KW - Power Control 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 (pointto- point and/or point-to-multipoint radio bearers) in any cell/sector of the network in which multicast users are residing. The mechanism is evaluated through several realistic scenarios and is compared with several radio bearer selection mechanisms in order to highlight the enhancements that it provides. JF - Eighth Annual Wireless Telecommunications Symposium - WTS 2009, Prague, Czech Republic 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 - JOUR T1 - Evaluation of Different Power Saving Techniques for MBMS Services JF - EURASIP Journal on Wireless Communications and Networking, Hindawi Publishing Corporation Y1 - 2009 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos KW - LTE KW - MBMS KW - Power Control AB - Over the last years we have witnessed an explosive growth of multimedia computing, wireless communication and applications. Following the rapid increase in penetration rate of broadband services, the Third Generation Partnership Project (3GPP) is currently standardizing the Evolved-Multimedia Broadcast/Multicast Service (E-MBMS) framework of Long Term Evolution (LTE), the successor ofUniversalMobile Telecommunications System (UMTS).MBMS constitutes a point-to-multipoint downlink bearer service that was designed to significantly decrease the required radio and wired link resources. However, several obstacles regarding the high-power requirements should be overcome for the realization of MBMS. Techniques, such as Macrodiversity Combining and Rate Splitting, could be utilized to reduce the power requirement of delivering multicast traffic toMBMS users. In this paper, we analytically present several power saving techniques and analyze their performance in terms of power consumption. We provide simulation results that reveal the amount of power that is saved and reinforce the need for the usage of such techniques. ER - TY - CONF T1 - Optimal MBMS Power Allocation Exploiting MIMO in LTE Networks T2 - 2009 IEEE 69th Vehicular Technology Conference VTC2009 Spring, Barcelona, Spain Y1 - 2009 A1 - Christos Bouras A1 - Antonios Alexiou A1 - Vasileios Kokkinos A1 - Evangelos Rekkas KW - LTE KW - MBMS KW - Power Control AB - In the frame of the Long Term Evolution (LTE) of mobile networks, the provision of rich multimedia services, such as Mobile TV, is considered of key importance for the LTE proliferation in mobile market. To this end, Multimedia Broadcast/Multicast Service (MBMS) is envisaged to play an instrumental role during LTE standardization process. MBMS was introduced in the Release 6 of Universal Mobile Telecommunication System (UMTS) in order to deliver multimedia data from a single source entity to multiple destinations. However, downlink capacity in such networks is limited by base station transmission power. As an aftermath, in MBMS efficient power allocation techniques should be implemented so as to ensure the mass provision of multimedia applications to mobile users. In this paper we propose a power control scheme for efficient selection of MBMS bearers. The proposed mechanism on the one hand manages to economically utilize power resources during MBMS transmissions, while on the other hand exploits the performance enhancements emerged from Multiple Input Multiple Output (MIMO) antennas used in LTE networks. Simulation results indicate that the proposed scheme results to significant power and capacity improvements. JF - 2009 IEEE 69th Vehicular Technology Conference VTC2009 Spring, Barcelona, 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 - 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 - 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 - 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 - 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 -