Publications

@conference{3014,

title = {Mobility-Sensitive Power Control for MBSFN Cellular Networks},

author = {Christos Bouras and Andreas Papazois and Vasileios Kokkinos and Konstantinos Asimakis},

url = {https://telematics.upatras.gr/wp-content/uploads/2024/01/23404952a483.pdf},

year  = {2013},

date = {2013-03-01},

urldate = {2013-03-01},

booktitle = {The Ninth International Workshop on Heterogeneous Wireless Networks (HWISE - 2013), Barcelona, Spain, pp. 483-487},

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{3012,

title = {Power Management over Co-channel Femtocells in LTE-A Systems},

author = {Christos Bouras and Andreas Papazois and Vasileios Kokkinos and Georgios Diles},

url = {https://telematics.upatras.gr/wp-content/uploads/2024/01/14401569654615.pdf},

year  = {2012},

date = {2012-11-01},

urldate = {2012-11-01},

booktitle = {IFIP Wireless Days 2012, Dublin, Ireland, pp. 1-3},

pages = {1 – 3},

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2966,

title = {The Impact of FEC on Mobile Multicast Power Control},

author = {Christos Bouras and Antonios Alexiou and Andreas Papazois},

url = {https://telematics.upatras.gr/8740pid1140067/},

year  = {2010},

date = {2010-05-01},

urldate = {2010-05-01},

booktitle = {The Sixth Advanced International Conference on Telecommunications (AICT 2010), Barcelona, Spain, pp. 1-6},

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2958,

title = {An Enhanced Mechanism for Efficient Assignment of Multiple sessions towards LTE},

author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos},

url = {https://telematics.upatras.gr/1016mswim40a-alexiou/},

year  = {2009},

date = {2009-10-01},

urldate = {2009-10-01},

booktitle = {The 12th ACM Annual Conference on Modeling, Analysis and Simulation of Wireless Mobile Systems, Tenerife, The Canary Islands, Spain, pp. 384-391},

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2946,

title = {Optimizing MBMS Power Allocation Through HSDPA Transmissions},

author = {Christos Bouras and Antonios Alexiou and Evangelos Rekkas},

url = {https://telematics.upatras.gr/78073192pid822175/},

year  = {2009},

date = {2009-05-01},

urldate = {2009-05-01},

booktitle = {The Fifth Advanced International Conference on Telecommunications - AICT 2009, Venice, Italy, pp. 327-332},

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2940,

title = {An Efficient Mechanism for Power Control Optimization in MBMS Enabled UTRAN},

author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos},

url = {https://telematics.upatras.gr/9787wcnc2009/},

year  = {2009},

date = {2009-04-01},

urldate = {2009-04-01},

booktitle = {IEEE Wireless Communications and Networking Conference, Budapest, Hungary, pp. 1292-1297},

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2943,

title = {Optimal MBMS Power Allocation Exploiting MIMO in LTE Networks},

author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas},

url = {https://telematics.upatras.gr/8987vtc2009s_bouras/},

year  = {2009},

date = {2009-04-01},

urldate = {2009-04-01},

booktitle = {2009 IEEE 69th Vehicular Technology Conference VTC2009 Spring, Barcelona, Spain, pp. 1-5},

pages = {1 - 5 },

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2950,

title = {An Enhanced MBMS Power Control Mechanism towards Long Term Evolution},

author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos},

url = {https://telematics.upatras.gr/7433enhanced_mbms/},

year  = {2009},

date = {2009-04-01},

urldate = {2009-04-01},

booktitle = {Eighth Annual Wireless Telecommunications Symposium - WTS 2009, Prague, Czech Republic, pp. 1-6},

pages = {1 - 6 },

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2937,

title = {Evaluation of Different Radio Bearer Selection Approaches for MBMS in B3G Networks},

author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas},

url = {https://telematics.upatras.gr/8330ifip_ieee_wd2008_bouras/},

year  = {2008},

date = {2008-11-01},

urldate = {2008-11-01},

booktitle = {IFIP Wireless Days Conference 2008, Dubai, United Arab Emirates, pp. 1-5},

pages = {1 - 5},

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2934,

title = {A Novel Mechanism for Radio Capacity Maximization during MBMS transmission in B3G Networks},

author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas},

url = {https://telematics.upatras.gr/6332mswim2008_bouras/},

year  = {2008},

date = {2008-10-01},

urldate = {2008-10-01},

booktitle = {The 11th ACM/IEEE International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM 2008), Vancouver, British Columbia, Canada, pp. 185-192},

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2931,

title = {Balancing between Power Optimization and Iub Efficiency in MBMS enabled UMTS Networks},

author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos},

url = {https://telematics.upatras.gr/6573pwc2008_bouras/},

year  = {2008},

date = {2008-10-01},

urldate = {2008-10-01},

booktitle = {1st IFIP Wireless and Mobile Networking Conference (WMNC 2008) , Toulouse, France, pp. 355-368},

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2928,

title = {Efficient Assignment of Multiple MBMS Sessions in B3G Networks},

author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos and Evangelos Rekkas},

url = {https://telematics.upatras.gr/6968vtc2008_bouras/},

year  = {2008},

date = {2008-09-01},

urldate = {2008-09-01},

booktitle = {2008 IEEE 68th Vehicular Technology Conference – VTC2008 Fall, Calgary, Canada, pp. 1-5},

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2930,

title = {A Novel Power Counting Mechanism for Enhanced MBMS Performance in UMTS Networks},

author = {Christos Bouras and Antonios Alexiou and Evangelos Rekkas},

url = {https://telematics.upatras.gr/1110mwcn2008_bouras/},

year  = {2008},

date = {2008-09-01},

urldate = {2008-09-01},

booktitle = {1st IFIP Wireless and Mobile Networking Conference (WMNC 2008) , Toulouse, France, pp. 57-68},

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2922,

title = {Power Saving Methods for MBMS Transmissions in UTRAN},

author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos},

url = {https://telematics.upatras.gr/7228iscc2008_bouras/},

year  = {2008},

date = {2008-07-01},

urldate = {2008-07-01},

booktitle = {The Thirteenth IEEE Symposium on Computers and Communications – ISCC 2008, Marrakech, Morocco, pp. 374-379},

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},

pubstate = {published},

tppubtype = {conference}

}

@conference{2910,

title = {Power Saving Techniques in MBMS Multicast Mode},

author = {Christos Bouras and Antonios Alexiou and Vasileios Kokkinos},

url = {https://telematics.upatras.gr/6663wmunep2007_bouras/},

year  = {2007},

date = {2007-10-01},

urldate = {2007-10-01},

booktitle = {3rd ACM International Workshop on Wireless Multimedia Networking and Performance Modeling - ACM WMUNEP 2007, Chania, Crete, Greece, pp. 62-69},

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},

pubstate = {published},

tppubtype = {conference}

}