Abstract: For mobile terminal with limited power and terminal power factor is always ignored by existing vertical handoff mechanism, this paper proposes vertical handoff based on terminal energy consumption mechanism. In view of the network discovery stage, this paper puts forward an optimization algorithm of network discovery based on the terminal energy. In view of the handoff decision stage, the sampling points into the subsequent modules are reduced by prejudgment; then, the corresponding fuzzy logic method is designed for real-time and non-real-time businesses respectively; finally, real-time business using weighting factor completes the handoff, the handoff decision of non-real-time business is made based on difference threshold. Simulation results show that both network discovery time and interface activated number can be reduced in network discovery stage. Meanwhile, the call?drop?rate, the handoff number and the ping-pang effects can be reduced in the handoff decision stage. In conclusion, the effectiveness of the mechanism is demonstrated.

Key words: vertical handoff, terminal energy consumption, algorithm of network discovery, fuzzy logic

摘要： 针对移动终端有限的电量以及现有垂直切换机制往往忽略终端电能因素，提出了基于终端能耗的垂直切换机制。网络发现阶段，提出一种自适应调整网络接口激活时间间隔的网络发现策略。切换判决阶段，对采样点进行预判决，减少进入后续模块的采样点；为实时业务和非实时业务分别设计相应的模糊逻辑处理方法；实时业务引入权重因子完成切换判决，非实时业务通过差值门限算法进行切换判决。仿真结果显示，相比传统策略，该机制在网络发现阶段能够降低网络发现时间，减少网络接口激活次数；在切换判决阶段能够降低掉话率，减少网络切换次数以及乒乓效应发生次数，具有有效性。

关键词: 垂直切换, 终端能耗, 网络发现策略, 模糊逻辑