文档介绍：摘要
无线传感器网络是由大量集成了传感、数据收集、处理和无线通信功能的传感器节点构成的无线自组织网络,能量极为有限的特点决定了其MAC(ess Contr01)层协议的设计要以最小化能耗为首要目标。本文基于S—MAC( Sensor MAC)协议,研究了无线传感器中MAC层协议的节能策略,提出了节能高效的MAC层协议。
论文首先对典型的MAC层协议和节能机制进行了介绍,,指出了该协议中存在的问题。其次,以节能为目标,(Power Control Message Passing SMAC)协议,该协议采用消息分割和连续发送的策略,并结合“碰撞防止"策略,引入功率控制技术。,结果表明该协议可减少网络能量的消耗。第三,根据事件驱动型无线传感器网络的特点,(Event-Driven SMAC)协议,该协议定义了常规态和事件态两种网络状态,,在事件态下引入跨层优化的构想,并给出了基于事件的动态成簇算法,仿真结果表明该协议改善了节点的节能性能和网络时延性能,提高了事件监测的可靠性。
关键词:无线传感网络节能机制 S-MAC事件驱动通信负载延迟 NS2
Abstract
Wireless work(WSN)posed of a large number of sensors which
have functions of data sensing,gathering,handling energy
constraint in sen$or nodes iS one of the important characteristics of WSN,a critical
design issue for the MAC protocol OfWSN is to efficiently reduce energy consumption.
Based on the typical medium access control protocol,Sensor MAC(S—MAC),this
thesis analyses the energy—saving mechanisms in MAC protocols and proposes two
energy efficient MAC protocols.
Firstly,we introduce the typical MAC protocols in WSN and their energy—saving
a detailed introduction to S·MAC iS given,which is mainly
designed for discuss the energy-saving mechanisms and the details in energy
consumption of S-MAC,and poim out the problems existed in S-,
Power Control Message Passing SMAC(PCMP-SMAO is proposed to achieve the
goal of energy fragments are transmitted continuously after bemg marked ‘‘Fragment Indicator'’.Meanwhile,power control mechanism is introduced with
collision prevention that allows nodes to vary their transmission power
network simulation platform is established by NS-2 and simulation results show that
PCMP—SMAC reduces energy ,based on the characteristic of
event driven WSN,a Event-Driven Sensor MAC protocol(ED-SMAC)is
—SMAC defines work statuses:regular status and event status.