一种基于终端决策的自适应垂直切换算法

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。首先建立一个利用各种移动通信系统中的广播信道广播业务质量信息、支持基于移动终端侧进行垂直切换的通用模型,并描述业务质量评价指标的定义以及终端侧进行切换判决的处理流程。然后应用检测与估值理论提出一种支持这一模型的自适应预测切换算法。算法依据接收到的广播业务质量信息,预测下一时间段用户获得的服务质量,继而做出切换判决。最后给出算法自身执行过程中跟踪多个接入网络业务质量状态的仿真,并以终端获得的服务质量以及切换事件发生的概率为指标、与基于简单预测和线性预测的切换算法进行了对比仿真。该算法能够实时地为用户选择最佳的接入网络,并提高网络侧的资源利用率。

A Terminal-decision Based Adaptive Vertical Handoff Algorithm

Vertical handoff will be very important in future heterogeneous environment.A terminal-decision based common vertical handoff model using the broadcast channels in different systems,the decision process of this model and the definition of quality indices are presented.An adaptive decision vertical handoff algorithm using the detection and estimation theory to support this model is provided.The simulations show how the algorithm tracks the network quality state and what quality improvement the terminal gets.They are compared with the simple decision and linear decision and prove the proposed algorithm.The algorithm assures users of the best access technology and effective network utilization.