Implementation And Improvement Of The MAC Layer Of Zigbee Protocol Based On ARM7 Platform

Wireless Sensor Network(WSN) is an integration of sensor, detection, the short distance wireless communication, network information processing and low-power design technology. It is with a wide range of potential applications. It is also named as one of the most ten significant technologies on human life in the twenty-first century. WSN has been increasingly applied in military and civilian areas, and the technology related to wireless sensor network has become a hotspot.IEEE 802.15.4 working group started a low- rate wireless communication protocol after Zigbee scenario was presented. Finally, IEEE 802.15.4 working group and the Zigbce Alliance decided to set up a new communication protocol standards, which is named as "Zigbee".This study mainly focuses on the implementation of the MAC layer of Zigbee protocol, and makes some improvements for it in order to optimize network performance. The main work is as follows.1. The implementation of the MAC layer of Zigbee protocol is studied. Firstly the software and hardware platform are introduced. Then the whole design of MAC layer and the implementation approach for the MAC layer functions are analyzed. Last the function implementation is verified.2. The improvement for the CSMA/CA mechanism and time synchronization mechanism is studied. Considering the wireless sensor node's characters of low-cost, low-power, low-speed and high time synchronization accuracy, this study makes some improvements for the MAC layer to gain bigger throughput and higher time synchronization accuracy, and in the meantime to guarantee the low-power consumption of the sensor nodes.