SEMI-Dynamic Configuration Of SFN In Multi Cell Situation

With the rapid development of the mobile communication technology, voice service is no longer the main content of the communication system, and high speed data business is gradually occupied the market. People pay more and more attention on MBMS based SFN. But, the properties of multi cell MBMS limited in the topological structure of SFN, the mobility of users and the business distribution. So it is urgent to find a way to configure SFN effectively.There are static network mode and dynamic mode that have been researched. The static mode cannot ensure service continuities at every moment. The dynamic network mode changes the network configuration frequently. To solve this problem, this paper is devoted to finding a semi-dynamic configuration scheme, which can ensure user mobility and business continuity while saving system resources to maximum extent. Firstly, this paper has put forward a scheme that about semi-dynamic configuration of SFN in multi cell situation. Secondly, the optimization scheme was obtained by combining this scheme with the MBMS selection algorithm.We have put forward a semi-dynamic configuration scheme which bases on the situation of extension and contraction of SFN. The extension of SFN scheme is that when the users move to the border cells from the core cells, system will judge that if the average system throughput which has removed the mobile users is smaller than the threshold value. If smaller, it needs to extend the SFN. The contraction of SFN scheme is that system judges periodically that if the throughput of the border cell is smaller than the threshold value. If smaller, it needs to contract the SFN. The simulation results show that the scheme we proposed is superior to traditional static networking mode in the aspect of throughput, and the network topology update frequency is much lower than the dynamic networking mode. The method has the advantages of simple operation and is more suitable for the practical application of multicast system.The optimization scheme has combined the semi-dynamic configuration scheme with the MBMS selection algorithm. It ensures the business continuity and SFN performance while saving power resource to maximum extent. The simulation results show that the optimization scheme is superior to traditional static networking mode in the aspect of power consumption and throughput, and to update the network topology structure in low frequency. This scheme have made a balance in the performance of the system and saving resources.