Abstract: Aiming at the problem that the current vertical handoff algorithm of heterogeneous wireless networks had many handover times and the quality of service was difficult to meet the practical application needs, in order to achieve better quality of service for heterogeneous wireless networks, we proposed a vertical handoff algorithm of heterogeneous wireless networks based on improved Markov process. Firstly, the overall performance evaluation index system of heterogeneous wireless networks was established. Secondly, the weight of the overall performance evaluation index of the network was determined by grey relational analysis method. Finally, the state of heterogeneous wireless networks was predicted by Markov decision process, and the optimal access network was selected, and its performance was tested and analyzed by the simulation and comparative experiment of vertical handoff of heterogeneous wireless networks. The experimental results show that compared with other vertical handoff algorithms of heterogeneous wireless networks, the proposed algorithm can reduce the average handoff times, avoid frequent handoff, greatly reduce the packet loss rate of network data transmission, improve user satisfaction and achieve higher quality of service.

Key words: heterogeneous wireless networks, vertical handoff, grey , relational analysis, Markov process, access selection