移动自组网能量保护策略的研究

【作者】 陈曦；

【导师】 唐少先；

【作者基本信息】 中南大学 ， 通信与信息系统， 2007， 硕士

【摘要】 随着现代无线通信技术和因特网的发展与进步，人们对移动信息服务的需求也日益增长，任何人在任何时间、地点都能够获取信息并与他人通信的要求，已经成为人们对现代信息网络的切实需求。AdHoc网络，由于其无需固定基础设施支持、能快速、简单组网，而且按照其设计的初衷，能够自组织、自修复，因此，正在成为下一代无线网络的有力竞争者。降低能量消耗是无线网络协议中最重要的设计目标之一，MAC层的功率管理机制是降低无线网络能量消耗的重要手段。本文首先总结了移动自组网能量研究现状，阐述了移动自组网中节能策略面临的问题，并对基于网络层以及MAC层能量的节能策略进行了比较和分析，总结了它们的优缺点以及未来的发展方向。然后详细的描述了移动自组网MAC层功率管理原理，以及MAC的功率管理策略的研究方向。本文在对802.11PSM的工作模式进行深入研究的基础上，提出了在网络负载较轻情况下的一种新的节能策略——802.11EPSM，该节能策略通过ATIM帧信息交换，改变了在一个BI周期里面802.11PSM只能将数据传送一跳的问题，使数据包能够尽可能的在一个BI周期中向下游节点传送，从而使得中间节点苏醒周期减少，达到节能的目的。同时通过ATIM帧信息交换使得节点能够根据数据包的数量来预测数据到达节点的时间，从而节点只需要在相应的时间苏醒，错开了节点的竞争周期，达到节能的目的。通过仿真实验结果表明与802.11PSM相比，EPSM在减少传输时延、减少能耗以及提高节点生存时间等方面较PSM有了较大的提高，在BI周期中数据包发生率低，且数据包经过的中间节点较多时，节能效率甚至可以比802.11PSM提高30％以上。更多还原

【Abstract】 With the development of wireless communication and Internet, the demand for mobile information services is growing gradually. Anybody, at any time and any location need to get access to information and contact with others. Ad Hoc networks, due to its ability of self-orgnization and self-repairing, is becoming a strong competitor of the next generation wireless networks. To increase the energy efficiency is the most important aim of designing wireless network protocols. The energy saving mechanism at MAC is one of the important approaches of improving energy efficiency of wireless networks.This paper firstly summarized the recent research profile of Ad Hoc networks, introduced the problems of increasing energy efficiency, compared and analyzed different approaches of energy saving at MAC, and indicated the direction of future work, then described thoroughly the principles of energy saving mechanism at MAC.This work presented a new energy saving approach-802.11EPSM when the data load was not heavy, based on deep research of 802.11PSM. 802.11EPSM improves PSM model, which could only send one package in one BI, by sending as many packages as possible in one BI through the information exchanging of ATIM frame, and at the same timedramatically reduces transfer delay, and prolongs the life span of central nodes to save energy using central nodes alternant wake-up. The results of simulation shows that EPSM has better performance than PSM in terms of decreasing transportation delays, saving energy, and prolonging life span of nodes, and has low rate of producing BI data packets, and energy efficiency is more than 30% higher than 802.11PSM when the data packets transit through many interim nodes.更多还原