@conference {3014, title = {Mobility-Sensitive Power Control for MBSFN Cellular Networks}, booktitle = {The Ninth International Workshop on Heterogeneous Wireless Networks (HWISE - 2013), Barcelona, Spain}, year = {2013}, month = {March 25 - 28}, pages = { 483 - 487 }, abstract = {Cellular networks? Multimedia Broadcast/Multicast Service (MBMS) over a Single Frequency Network (MBSFN) allows broadcasting cell signals to constructively interfere and users to take advantage of increased bitrates compared to other broadcasting technologies. In this paper, we present our work on the optimization of the power control for future cellular networks that employ MBSFN transmission scheme. We propose a novel simulator and optimizer that can minimize the transmission power of individual cells taking into account the changing positions of users. In order to read descriptions of the various scenarios, the simulator uses the eXtendable Temporal Network Description Language (XTNDL), a language that is defined in this paper. The optimizer?s engine can be used in conjunction with the simulator or can be modified to read real time measurements from a real network.}, keywords = {Power Control}, author = {Christos Bouras and Andreas Papazois and Vasileios Kokkinos and Konstantinos Asimakis} } @conference {3012, title = {Power Management over Co-channel Femtocells in LTE-A Systems}, booktitle = {IFIP Wireless Days 2012, Dublin, Ireland}, year = {2012}, month = {21-23 November}, abstract = {The use of femtocells has been an attractive solution since it achieves better coverage and capacity and low cost for deployment and maintenance. However, their performance can be compromised by the cross-tier interference with existing macrocell infrastructure or between adjacent femtocells, especially in the case of co-channel deployment. One way to address this, is adjusting the transmit power of every femto base station with respect for overall performance. To this direction, we have implemented a framework that simulates femtocell overlays over LTE-Advanced (LTE-A) macrocellular systems. The framework allows power management over user-defined femtocell deployment, deciding their power levels according to three different power schemes. The resulting throughput is presented for every point of the macrocell in a user-friendly GUI. In this paper, we present the design of this framework and discuss the results.}, keywords = {Femtocell, Power Control}, author = {Christos Bouras and Andreas Papazois and Vasileios Kokkinos and Georgios Diles} } @article {3101, title = {A study of Forward Error Correction for Mobile Multicast}, journal = {International Journal of Communication Systems, Wiley InterScience}, year = {2011}, pages = { 607 - 627}, abstract = {

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.

}, keywords = {FEC, MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Andreas Papazois} } @inbook {3138, title = {Efficient Power Allocation in E-MBMS Enabled 4G Networks}, booktitle = {Wireless Network Traffic and Quality of Service Support: Trends and Standards}, year = {2010}, pages = { 458 - 488}, publisher = {IGI Global}, organization = {IGI Global}, chapter = {18}, abstract = {

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.

}, keywords = {LTE, MBMS, Power Control}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos} } @conference {2966, title = {The Impact of FEC on Mobile Multicast Power Control}, booktitle = {The Sixth Advanced International Conference on Telecommunications (AICT 2010), Barcelona, Spain}, year = {2010}, month = {May 9 - 15}, pages = {1-6}, abstract = {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.}, keywords = {FEC, LTE, MBMS, Power Control}, author = {Christos Bouras and Antonios Alexiou and Andreas Papazois} } @article {3089, title = {An Improved MBMS Power Counting Mechanism towards Long Term Evolution}, journal = {Telecommunication Systems Journal, Springer Verlang}, volume = {43}, year = {2010}, pages = { 109 - 119}, abstract = {

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.

}, keywords = {LTE, MBMS, Power Control}, author = {Christos Bouras and Antonios Alexiou and Evangelos Rekkas} } @article {3088, title = {An Improved Mechanism for Multiple MBMS Sessions Assignment in B3G Cellurar Networks}, journal = {Wireless Networks, Springer Verlang}, volume = {16}, year = {2010}, pages = { 671 - 686}, abstract = {

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.

}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas} } @inbook {3139, title = {Radio Resource Management for E-MBMS Transmissions towards LTE}, booktitle = {Evolved Cellular Network Planning and Optimization for UMTS and LTE}, year = {2010}, pages = { 331 - 360}, publisher = {Auerbach Publications, CRC Press, Taylor and Francis Group}, organization = {Auerbach Publications, CRC Press, Taylor and Francis Group}, chapter = {9}, abstract = {

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{\textpm}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{\textpm}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.

}, keywords = {LTE, MBMS, Power Control}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos} } @article {3084, title = {Cost Analysis and Efficient Radio Bearer Selection for Multicasting over UMTS}, journal = {Wireless Communications and Mobile Computing, Wiley InterScience}, year = {2009}, pages = { 1159 - 1172}, abstract = {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.}, keywords = {Cost analysis, MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas} } @conference {2940, title = {An Efficient Mechanism for Power Control Optimization in MBMS Enabled UTRAN}, booktitle = {IEEE Wireless Communications and Networking Conference, Budapest, Hungary}, year = {2009}, month = {5 - 8 April}, pages = { 1292 - 1297 }, abstract = {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.}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos} } @conference {2950, title = {An Enhanced MBMS Power Control Mechanism towards Long Term Evolution}, booktitle = {Eighth Annual Wireless Telecommunications Symposium - WTS 2009, Prague, Czech Republic}, year = {2009}, month = {22 - 24 April}, abstract = {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.}, keywords = {LTE, MBMS, Power Control}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos} } @conference {2958, title = {An Enhanced Mechanism for Efficient Assignment of Multiple sessions towards LTE}, booktitle = {The 12th ACM Annual Conference on Modeling, Analysis and Simulation of Wireless Mobile Systems, Tenerife, The Canary Islands, Spain}, year = {2009}, month = {26 - 30 October}, pages = { 384 - 391}, abstract = {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.}, keywords = {LTE, MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos} } @article {3091, title = {Evaluation of Different Power Saving Techniques for MBMS Services}, journal = {EURASIP Journal on Wireless Communications and Networking, Hindawi Publishing Corporation}, year = {2009}, abstract = {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.}, keywords = {LTE, MBMS, Power Control}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos} } @conference {2943, title = {Optimal MBMS Power Allocation Exploiting MIMO in LTE Networks}, booktitle = {2009 IEEE 69th Vehicular Technology Conference VTC2009 Spring, Barcelona, Spain}, year = {2009}, month = {26 - 29 April}, abstract = {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.}, keywords = {LTE, MBMS, Power Control}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas} } @conference {2946, title = {Optimizing MBMS Power Allocation Through HSDPA Transmissions}, booktitle = {The Fifth Advanced International Conference on Telecommunications - AICT 2009, Venice, Italy}, year = {2009}, month = {24 - 28 May}, pages = { 327 - 332}, abstract = {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.}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Evangelos Rekkas} } @conference {2931, title = {Balancing between Power Optimization and Iub Efficiency in MBMS enabled UMTS Networks}, booktitle = {1st IFIP Wireless and Mobile Networking Conference (WMNC 2008) , Toulouse, France}, year = {2008}, month = {1 - 3 October}, pages = { 355 - 368}, abstract = {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.}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos} } @conference {2928, title = {Efficient Assignment of Multiple MBMS Sessions in B3G Networks}, booktitle = {2008 IEEE 68th Vehicular Technology Conference {\textendash} VTC2008 Fall, Calgary, Canada}, year = {2008}, month = {22 - 25 Septemer}, pages = { 1 - 5}, abstract = {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.}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas} } @conference {2937, title = {Evaluation of Different Radio Bearer Selection Approaches for MBMS in B3G Networks}, booktitle = {IFIP Wireless Days Conference 2008, Dubai, United Arab Emirates}, year = {2008}, month = {24 - 27 November}, abstract = {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.}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas} } @conference {2934, title = {A Novel Mechanism for Radio Capacity Maximization during MBMS transmission in B3G Networks}, booktitle = {The 11th ACM/IEEE International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM 2008), Vancouver, British Columbia, Canada}, year = {2008}, month = {27 - 31 October}, pages = { 185 - 192}, abstract = {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}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas} } @conference {2930, title = {A Novel Power Counting Mechanism for Enhanced MBMS Performance in UMTS Networks}, booktitle = {1st IFIP Wireless and Mobile Networking Conference (WMNC 2008) , Toulouse, France}, year = {2008}, month = {30 September - 2 October}, pages = { 57 - 68}, abstract = {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.}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Evangelos Rekkas} } @conference {2922, title = {Power Saving Methods for MBMS Transmissions in UTRAN}, booktitle = {The Thirteenth IEEE Symposium on Computers and Communications {\textendash} ISCC 2008, Marrakech, Morocco}, year = {2008}, month = {6 - 9 July}, pages = { 374 - 379}, abstract = {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.}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos} } @conference {2898, title = {MBMS Power Planning in Macro and Micro Cell Envirohments}, booktitle = {Second IEEE Workshop on multimedia Applications over Wireless Networks(MediaWiN 2007), Aveiro, Portugal}, year = {2007}, month = {1 July}, pages = { 33 - 38}, abstract = {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.}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas} } @conference {2895, title = {A Power Control Scheme for Efficient Radio Bearer Selection in MBMS}, booktitle = {8th International Symposium on a World of Wireless, Mobile and Multimedia Networks, - WoWMoM 2007, Helsinki, Finland}, year = {2007}, month = {18 - 21 June}, pages = { 1 - 8}, abstract = {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.}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Evangelos Rekkas} } @conference {2909, title = {Power Efficient Radio Bearer Selection in MBMS Multicast Mode}, booktitle = {10th ACM - IEEE International Symposium on Modeling, Analysis and Simulation of Wireless and Mobile Systems - MSWIM 2007, Chania, Crete, Greece}, year = {2007}, month = {22 - 26 October}, pages = { 261 - 268}, abstract = {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.}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas} } @conference {2910, title = {Power Saving Techniques in MBMS Multicast Mode}, booktitle = {3rd ACM International Workshop on Wireless Multimedia Networking and Performance Modeling - ACM WMUNEP 2007, Chania, Crete, Greece,}, year = {2007}, month = {26 October}, pages = { 62 - 69}, abstract = {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.}, keywords = {MBMS, Power Control, UMTS}, author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos} }