In heterogeneous environments, vertical handoff among the networks has a major impact on QoS ( Quality of service). However,mobile terminal switching performance between heterogeneous networks is not ideal. This paper proposes an adaptive vertical handoff decision algorithm. This algorithm considers the current battery level of terminal,uses cost function based on user applications, chooses and evaluate access network, and determines whether current business needs switching. Simulation results show that the pro- posed algorithm can effectively prolong the working time of the terminal, reduce the ping-pong effect, and improve switching performance and business service quality.%在未来的异构环境中，网络间的垂直切换将对QoS保证产生重要影响。针对移动终端在异构网络间切换不理想的问题，提出了一种自适应的垂直切换判决算法。采用基于用户多应用的代价函数对接入网络进行评估与选择，综合考虑移动终端当前的电池电量，判断当前业务是否需要进行网络切换，使移动终端能自适应地进行切换判决。仿真结果表明，该算法可以有效地延长移动终端的工作时间，减少乒乓效应，提高系统的切换性能，改善业务的QoS。
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