Research on improvement in the handoff performance for high-speed mobile service

This paper focus on the deterioration of handoff performance for high-speed mobile services. To balance the conflict between handoff failure probability and system capacity, the thesis introduces a hierarchical cellular system. A dynamic velocity estimation algorithm based on the overlapping cell sojourn time is proposed. Furthermore, this paper proposes an efficient hierarchical handoff scheme. This scheme uses velocity property as intertier´s handoff rule while uses the pilot signal strength as intratier´s handoff rule. From the simulation results, the conclusion is given that the new scheme not only ensures low handoff failure probability for high-speed mobile services but also enhances the capacity of hierarchical system, and optimizes the handoff performance for all kinds of services