一种无线传感器网络中多应用系统级分布式接入控制策略

本文从无线传感器网络中多应用场景下的能量管理问题出发提出了一个系统级分布式接入控制策略.其目的为在一定的网络初始配置能量的前提下最大化总用户收益期望值.在设计该策略时,本文将多应用接入控制问题抽象成为一个特殊的“动态随机背包问题”,并采用相关理论对该问题建立了模型.为了求解这一模型,本文还提出了一个估计应用Reward及Cost联合概率分布的方案.并采用相关算法对该模型进行了求解,并据此设计了最优系统级分布式接入控制策略.经实验表明,本文提出的分布式接入控制策略能在各种网络初始能量配置下获取显著的总用户收益期望值的提高.另外,经实验还发现可以采用一个最优阈值的＂阈值准则＂来获取次优的接入控制效果,从而大大简化最优接入控制策略的设计.

System Level Distributed Admission Control Scheme for Wireless Sensor Networks in the Presence of Multiple Applications

The system level distributed admission control scheme for wireless sensor network (WSN) in the presence of multiple applications is developed. The objective of the admission control scheme is to gain the maximum expected over- all reward under the residual energy constraint of the network. In order to design the admission control scheme, the problem of admission control for multiple applications is abstracted as a dynamic and stochastic knapsack problem. The related theory is employed to model the problem. A scheme to estimate the joint probability distribution of the Reward and Cost of the applications is proposed, which is needed in solving the problem. Then, the related algorithms are used to solve the problem. Based on the result, the system level distributed optimal admission control scheme is devel- oped. The experimental results show that the obvious improvement on the expected overall reward is gained by the ad- mission control scheme in all the investigated scenarios. In addition, an optimal threshold policy is found to gain the sub-optimal expected overall reward in the experiments, which can simplify the design of optimal admission control greatly.