基于加速度预测的异构网络切换算法

摘要

本文为高速移动终端提供一种基于加速度预测的异构网络垂直切换算法，使用场景如高速公路的直线路段。利用加速度预测算法得到下一采样时刻的速度，将预测速度与采样时间相乘得到终端运动距离，然后将所得到的运动距离与当前终端的位置进行矢量叠加得到下一时刻的位置。最后利用距离与信号强度之间的关系分别对下一采样时刻的 WIMAX 网络和LTE网络的信号强度进行预测。根据预测到的信号强度，结合经典的基于驻留时间和迟滞电平算法，提出了一种有效解决乒乓效应和切换延时的异构网络切换算法。通过实验可得，相比较于传统基于驻留时间算法，本算法在保证信号强度可靠的前提下，能减少约10%切换的次数，并降低切换延时。%In this paper, we proposed a vertical handover algorithm based on speed prediction for high-mobility users, such as the scenario of the highway. The algorithm predicts the RSS(received signal strength) of WIMAX and LTE networks in the next time based on the velocity obtained by APA(acceleration prediction algorithm). Velocities are predicted by APA. Then velocities multiply their timeslots to get moving distance respectively. Then current positions are added with moving distances, thus gets next time‘s positions. Finally distance between AP (access point)and MN(moving node) are calculated by the relationship between distance and present RSS. In the end, the next time‘s RSS are predicted. Then an effective handover algorithm is proposed using the predicted RSS aiming to reduce the handover times and shorten handover latency. The simulations results indicate that, the proposed algorithm can reduce about 10%handover times and reduce handover latency with sufficient RSS is guaranteed in communication, comparing to the traditional dwell time algorithm.