Research On Handover Algorithm In Heterogeneous Wireless Communication Network

With the communication technology developing, people ask for the better communication performance, the variety of networks can effectively improve the handover performance. So, the heterogeneous network is becoming one best development. With the introduction of femtocell technology, better performance of the handover system is requested. To solve such problems in the heterogeneous network, like the complex access standards, the deterioration of radio link failure and the poor handover performance, this paper proposes the following handover algorithms by means of the handover decision mechanism.Firstly, this paper proposes a layer handover algorithm based the admission control mechanism. Most existing heterogeneous network handover algorithms doesn't consider the limitations of femtocell technology. When users handover networks, it is prone to bring higher delay and handover failure rate. To solve such problems, this algorithm mainly includes the following two points:1?In the network selection process, the decision parameters are stratified to reduce the complexity of the algorithm, and then optimize the network selection sorted by the multiple attribute decision mechanism. 2?It generates one additional speed access mechanism to improve the handover success rate by solving the femtocell limitations such as the low power and the narrow coverage radius. The results show that this algorithm can reduce the handover delay effectively, and improve the success rate of handover significantly.Secondly, this paper proposes a step-debugging handover algorithm based the self-optimizing network mechanism. Most existing heterogeneous network handover algorithms are focused on one single handover performance. However, because the system performances are always associated with each other, the optimum design point should emphasis on reducing the indicators which significantly affect the quality of the communication system based the overall performance. This algorithm mainly includes the following two points:1?The system samples current Radio Link Failure ratio, Handover Failure ratio and Ping-pong Handover ratio for the step-debugging handover mechanism by the layer handover algorithm as mentioned above. 2?The step-debugging handover mechanism debugs the handover parameters gradually through the analysis of handover performances, then updates to the decision system to improve the handover success rate. This mechanism is conducive to the early network selection and the late performance debugging, so as to achieve the whole performance optimization. The results show that this algorithm can improve the handover success rate significantly.