Researches On Radio Resources Management In Multicast Broadcast Single Frequency Network

Multicast Broadcast Single Frequency Network (MBSFN), as a transmission mode for multicast services in cellular networks, can improve the utilization of spectrum resources and the coverage of wireless network to guarantee the quality of service (QoS) of multicast services. With the increasing demand of radio resources for the rapid development of radio access technologies and related services, multicast and unicast services share available radio resources. Therefore, the radio resources management (RRM) for multicast and unicast services is becoming a new but crucial issue in MBSFN field and catches attentions in both research and industry societies.This dissertation mainly focuses on discussing and solving the three problems of handover, load balancing and packet scheduling in RRM for MBSFN, and it is also a collection of results achieved during the author participating in the National Science and Technology Major Project "Research of IMT-Advanced Wireless Transmission Technology (No.2008ZX03003-004)" and "Research of IMT-Advanced Cross-layer Optimization Technology (No.2010ZX03003-001)".The main contents of this dissertation are issued as follows:In the handover algorithms for MBSFN, to solve the problem of the demanded radio resources for multicast services, the handover algorithm of minimizing the demanded radio resources for multicast services and the handover algorithm of load balancing for the multicast and unicast services are proposed. The system model of the demanded radio resources for multicast services is formulated by analyzing Signal to Interference plus Noise Ratio (SINR) of single frequency network (SFN) mode and point-to-point (PTP) mode, and the minimization problem of the demanded radio resources for multicast services is solved by the switch between the two transmission modes of SFN and PTP; then the system model of the demanded radio resources for the multicast and unicast services in a cell is formulated by considering the demanded radio resources for unicast services, and the minimization problem of the demanded radio resources for the maximum load cell is solved by the dynamic handover threshold. The simulation results show that the proposed handover algorithms can greatly reduce the demanded radio resources of multicast services to improve the spectrum utilization.In the load balancing algorithms for MBSFN, to avoid the network congestion of the different demanded radio resources for multicast services, the load balancing algorithm in MBSFN areas and the load balancing algorithm between MBSFN areas are proposed. The system model of the demanded radio resources for a cell in MBSFN areas is formulated by analyzing the SINR of SFN mode and point-to-multipoint (PTM) mode, and the minimization problem of the demanded radio resources for the maximum load cell is solved by multicast QoS optimization; then the system model of the demanded radio resources for the maximum load cell in MBSFN is formulated by the two transmission modes of SFN and PTM, and the Simulated Annealing (SA) algorithm is adopted to solve the minimization problem of the maximum of the demanded radio resources for the maximum load cell in each MBSFN area. The simulation results show that the proposed load balancing algorithms can efficiently reduce the demanded radio resources of the maximum load cell for the better load balancing.In the packet scheduling algorithms for MBSFN, to solve the tradeoff problem in the delay performance of real-time multimedia services and the average energy of mobile stations, the packet scheduling algorithm for guaranteeing the QoS requirements of real-time multicast services and the energy efficient packet scheduling algorithm for the real-time multicast and unicast services are proposed. The function of scheduling priority is defined by analyzing multiple utility factors, and the parallel scheduling is adopted to reduce the computation complexity; then the system model of the average energy of mobile stations is formulated by analyzing the energy for the transmission and states exchange of mobile stations, and the circulation and iteration algorithm is adopted to solve the minimization problem of the average energy of mobile stations. The simulation results show that the proposed packet scheduling algorithms can guarantee the minimum average energy of mobile stations with satisfying the delay performance of real-time multimedia services.