The Research Of Protocol And Operating System For Wireless Sensor Network

Wireless sensor network is a intelligent information system intergrated with information acquisition, information transmission, information processing, which synthesizes micro-electro-mechanical system, sensor technology, embedded computing technology, modern network and wireless communication technology, distributed information processing technology, can cooperate in real-time monitoring, sensing and colletcting various environmental or monitored -information through kinds of integrated micro-sensors, all these information sent out via wireless ways, and arriving user termianls through ways of own multi-hop network, so that achieving the connection of physical world , computer world and human society.Wirless sensor network owns broadly application prospect, which considered to be one of the tremendous influential technologies in 21st, has potential practical value in many important areas such as military defense, industry agriculture, urban management, bio-medical treatment, emergency rescue, remote control of dangerous regional, environmental moniotoring and so on, and has been highly noticed by academic and industry communities in manng countries.This article is mainly based on TinyOS for the study of wireless sensor network protocol, putting forward a advanced program about TinyOS scheduling strategy. In this paper, first we analyse the structure of wireless sensor network in two aspects --single node structure and network structure, basing on wireless sensor network structure ,and anayles the function and protocol of physical layer,data link layer,network layer,transport layer,application layer, we comparison several dedicated wireless sensor network operating system.As a typical wireless sensor networks operating syetem,TinyOS is utilized widely,houever,its existing scheduling strategy adopts first-come-first served scheduling strategy,and it can't guarantee systematic respondent performance.When system becomes overloaded,urgent tasks can't be executed reliably and timely,causing communication performance to descend. Contraposing the particularities of wireless sensor networks and its node, based on task scheduling theory in embedded real-time system, this thesis adopts preemptive threshold scheduling strategy in TinyOS to improve wireless sensor networks' real-time performance and reliability.At last, through TOSSIM imtation,this thesis tests and analyzes the unmodified TinyOS and the modified one.The results prove that the preemptive threshold scheduling strategy presented in this thesis is efficient and rational.