Design And Implementation Of MAC Protocol For Wireless Sensor Networks Based On TinyOS

Wireless Sensor Network(WSN)is a highly potential application subject.It is considered as one of the most important research fields in the 21 st Century.The Wireless Sensor Network has expanded the people's ability to obtain information,can provide us with the most direct,accurate and truthful information.Therefore,it has a wide range of applications,and can be used in military,national defense,industrial and agricultural control,smart city,biological medicine,environmental monitoring,remote control of dangerous areas and many other fields.The MAC(Medium Access Control)protocol in wireless sensor networks has a direct impact on the performance of wireless sensor networks,so many researchers are focus on MAC protocol's research.The MAC protocol is usually random access and polling system with two control modes,polling system effectiveness due to its fairness,effective control,on computer,communications,industrial manufacturing and other aspects.This paper is aimed at research on needle polling system.The polling system is generally working through a server and N queues form,divided into threshold,complete and limited(K=1)three types of service system.The optimization and improvement of polling system usually proceed from the query sequence,service strategy,etc.In addition,the software development of Wireless Sensor Network technology is appeared in the large number of opening source,semi open source and business applications.In hardware aspect,many low-cost,low-power and high-performance microprocessors are emerged for wireless sensor networks.In this paper,the existing wireless sensor network MAC protocol in-depth analysis of the basis,combining the idea of polling control,raise one kind of differentiation of prioritized polling control.This paper have been done with these following research:1.Take research of threshold,complete,limited(K=1)three types of service system;through the method of Markov Chain and the probability generating function of three kinds of the mean queue length,the average delay analysis.2.Based on the MAC of TinyOS's design,based on the IEEE 802.15.4 MAC protocol,a MAC frame structure with periodic frame and the polling control function in the process of the system are designed.3.The development and implementation of the threshold,complete and limited(k = 1)three types of polling system have CC2538 node work as a hardware platform and TinyOS work as a software platform,combined with improved MAC frame in the experimental platform to implement,through the calculation and analysis of three types of wheels.The experimental results show that the established mathematical model accurately analyzes the index of the three types of polling system.4.This paper is studied about prioritized polling control system,establishes the mathematical model for the prioritized polling control system and implements the system on the experimental platform.The high priority node uses the complete service mode,and the low priority node uses the threshold service mode,in the MAC frame structure,a priority level field is added to identify the priority level of the node.Finally,the system calculated the average queue length and average delay of theoretical and experimental values were compared with the threshold,complete,limit(k = 1)three type of polling system.The experimental results show that the polling control system of prioritized effective distinction between the center of the high priority nodes and low priority nodes;it can guarantee the service quality of high priority nodes,at the same time low priority nodes have been optimized to a certain extent.