Improved vertical handoff scheme in heterogeneous wireless networks
异构无线系统中一种改进的垂直切换方案

Vertical handoff in heterogeneous wireless networks should consider multiple factors, so an improved vertical handoff scheme is proposed in this paper. First cost function is improved for network cost in this scheme. Then according to remaining battery, different handoff method is adopted. At last handoff voice traffic remains in present network so as to reduce handoff frequently. Numerical results demonstrate that our scheme can reduce blocking rate, average handoff times, average call charge well , and improve performance of system efficiently. It can be used in practice.