基于移动性感知的无线传感器网络GTS自适应分配策略

Adaptive guaranteed time slots allocation policy in wireless sensor networks with mobility awareness

为解决移动无线传感器网络中节点连通性较弱的问题,提出一种包含不同移动性节点的无线传感器网络提升移动节点连通性的保障时隙(GTS,guaranteed time slot)分配策略。首先,采用Kalman滤波预测模型得到用户下一阶段位置;接下来,引入一种考虑速度、方向和相对移动性的节点移动程度界定方法,并在此基础上进行GTS预约优先级的初步确定;随后,根据移动节点对所预约时隙的使用反馈情况自适应调整预约优先级;最后,根据节点的优先级决定GTS时隙的使用顺序及额外预留时隙的使用权。仿真结果显示,提出的分配策略在具有不同移动性节点的网络中,能够提高移动节点接入的成功率,保证较低的分组平均传输时延及较高的分组投递率。此外,采用基于反馈机制的自适应预约优先级调整策略能够显著增加整个网络中已分配时隙的正确使用率。

To improve the connectivity in mobile wireless sensor networks,an adaptive GTS（guaranteed time slot） allocation algorithm with nodal mobility awareness was proposed.At first,the nodal location in next state was given by Kalman filters forecasting model.Then,a method that considered velocity,direction and relative mobility was used to define mobility level,based on which the nodal priorities for GTS reservation could be determined initially.Subsequently,the priorities could be adjusted adaptively according to the usage status feedback from allocated slots.Finally,the priorities could be used to determine the order for using GTS and the right of use an extra reservation slot.Simulation results show that the proposed scheme could increase the success rate of random access and ensure a lower average packets transmission delay and higher delivery ratio.Furthermore,with the adaptive adjustment scheme for reservation priorities base on usage feedback,the rate of correct utilization of allocated slots is increased significantly in the overall networks.