Investigation Of TD-LTE And WiMAX Network Interworking And Handoff Control Technology

With the rapid development of communication industry, users have higher expectations for communication.This not only requires a stable voice communication system, but also requires the system capable for data communications and multimedia communications,making the convergence of heterogeneous networks a very huge trend.As a long-term evolution version of TD-SCDMA, TD-LTE becomes the direction of the next-generation mobile communications technology for its mature technology of "OFDM,MIMO,IP technology and TD-SCDMA".But the market still faces many challenges:First, the technology is not mature enough for large-scale implementation.Second,its equipments,particularly the terminals are difficult to fulfill the business requirements.WiMAX can provide the data rate to 75Mbps,which meets the demand of high-speed data services of the hot spots.However, WiMAX does not support high-speed mobile with the seamless roaming at this stage.So the promotion of TD-LTE and WiMAX Convergence is feasible not only for providing the users with the high-quality voice services based on the mobility of cellular technology, but also for enabling the users to enjoy high-speed data multimedia services based on the wireless broadband access. So TD-LTE and WiMAX Network Convergence will become an efficient and practical Networking Method. The Convergence of TD-LTE and WiMAX network is based on vertical handoff of hybrid networks, but current handoff technologies are mainly for horizontal handoff. For the specificity and complexity of vertical handoff, vertical handoff technology is still lack of detailed and deep research.There are still many key issues to be resolved.In this paper, the basic theories and key technologies of TD-LTE and WiMAX have been analyzed and researched deeply. The main work and results in the papers include the following aspects:(1)After the comparison between TD-LTE and WiMAX market positioning, this paper discusses the feasibility of network convergence and analyzes the feasibility of network convergence of TD-LTE and WiMAX based on transmission technologies,multiple access technologies, and channel bandwidth.(2) By analyzing the two kinds of common coupling method of heterogeneous network (tightly-coupled and loosely-coupled), and considering TD-LTE and WiMAX network reference architecture, this paper discusses two possible network convergence plans, also analyzes and compares the characteristics of the two plans, demonstrating that loosely-coupled convergence plan for TD-LTE and WiMAX is the best for the current situation, and then plans loosely-coupled plan as the mixed-mode network coverage.(3) This paper deeply analyzes the homogeneous network and heterogeneous network.For vertical handoff of the heterogeneous network, this paper provides an algorithm and handoff strategy on the received signal strength and a beacon to form the vertical handoff decision, and designs a seamless handoff based on the scheme in the vertical handoff strategy.This handoff mechanism effectively avoids the "ping-pong effect" of vertical handoff.