The Department of Computer Science at the University of Cyprus cordially invites you to the PhD Defense entitled:

Radio Resource Management for Efficient Multicast Service Provision in 3rd Generation Mobile Cellular Networks

Speaker: Christophoros Christophorou
Affiliation: University of Cyprus, Cyprus
Category: PhD Defense
Location: Room 148, Faculty of Pure and Applied Sciences (FST-01), 1 University Avenue, 2109 Nicosia, Cyprus (directions)
Date: Tuesday, April 19th, 2011
Time: 10:00-11:00 EET
Host: Constantinos Pattichis (pattichi AT

The introduction in wireless networks of multimedia services such as streaming video, mobile TV and others, increased the need for communication between one sender and many receivers, leading to the need of Point-to-Multipoint transmission, achieved mainly through the use of multicasting technologies. A first successful attempt to provide efficiently multimedia services in wireless mobile networks came with the introduction of MBMS (Multimedia Broadcast Multicast Service) system in UMTS (Universal Mobile Telecommunications System) Release 6 specifications. MBMS system is considered as one of the most important steps of the UMTS Network evolution since it provided it with a powerful tool to offer broadcast and multicast services efficiently, with the main benefit of major core- and radio- resource savings. Within the 3GPP standards group there is still a lot of ongoing work to define the appropriate standards for MBMS. Although the service and technical requirements are complete, still many design issues need to be considered for MBMS services to be provided in a more efficient way, especially in the UTRAN (UMTS Terrestrial Radio Access Network) part where the radio resources are limited. Adopting the Radio Resource Management (RRM) algorithms currently specified in the 3GPP documents to provide MBMS services, more than 30% of the Node-B’s total power has to be allocated to a single 64 Kbps MBMS service in order to cover the whole cell. This can make MBMS services too expensive since the overall UMTS network capacity is limited by the Node-B’s power source. Thus, in order to make MBMS services feasible and also attractable to the consumers, challenges are raised for more efficient RRM algorithms to be introduced. Therefore, during this Ph.D. dissertation we deal with this issue and investigated and proposed efficient, scalable and effective RRM algorithms controlling parameters such as handover criteria, transmit power and channel allocation, facilitating decisions targeting seamless handovers, increased network capacity and overall system performance (and thus achieve lower service costs) as well as acceptably good QoS for the users during the MBMS service provision in UTRAN.

Short Bio:
Christophoros Christophorou is a PhD candidate in Computer Science of the University of Cyprus. He has completed his undergraduate and graduate studies at the University of Cyprus (B.Sc. in Computer Science and M.Sc. in Advanced Computer Technologies, 2002 and 2005, respectively). He is currently working at the University of Cyprus in the area of wireless mobile networks. He has been a research associate at the department of Computer Science of University of Cyprus since April 2004, where he has been involved in the IST funded B-BONE, MOTIVE and C-MOBILE projects and ICT funded C-CAST project. His research interests include Radio Resource Management in 3G and beyond mobile Cellular Networks, specifically capacity and performance enhancements through dynamic and adaptive radio resource allocation and handover algorithms.

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