Research On Multi-services Group Handover Algorithm In Wireless Heterogeneous Networks

With the rapid development of communication technology, computer technology, wireless communication has developed to a new stage which is a heterogeneous integration of multiple wireless access technologies that differ in bandwidth, latency or cost. While users roaming in a heterogeneous network seamlessly, the vertical handover(VHO) between heterogeneous networks is needed. VHO is a term that refers to handover among heterogeneous wireless access networks,and handover decision is an important step of the whole VHO process.This paper foucs on the research of group vertical handover(GVHO) which refers to the scenario that many mobile users operate vertical handover at the same time or nearly simultaneously. The traditional VHO decision algorithms mainly focus on when or where to trigger handover for single user, in this case, if they were appled for GVHO scenario, it may lead to network congestion or the whole wireless network system damage while mobile users select the best network selfishly without considering other VHO users’ network selection results.A multi-services group handover algorithm under the constraint of blocking probability is proposed to solve the network congestion problem of group handover in the multi-services heterogeneous networks. Users are assigned with different handover priorities according to their service types, and the handover is controlled under blocking probability constraints for the users with same priority. The proposed algorithm disperses the users into different slots to avoid a large amount of users selecting the same network at the same time. The simulation results show that the proposed algorithm can keep the handover blocking probability of the system manageable and meet the QoS requirements of different services.