The Research Of Media Access Control Algorithm In Wireless Sensor Network

Advances in MEMS(Micro-Electro-Mechanism System), SOC(System on Chip) and Wireless Communications have made WSN(Wireless Sensor Network) possible, which has a wide range of potential applications including national defence, environment monitoring , medical systems, target tracking, habitat sensing and fire detection. Like in all shared-medium networks, medium access control(MAC) is an important technique that enables the successful operation of the wireless sensor network.The research of this thesis is based on the analysis of a great deal of recent technical reports and research results on WSN and its main work include:1. From the energy consumption, network topology and efficiency, the difficulty in designing MAC and major sources of energy waste aredescribed.2. The recent representative MAC protocols are discussed and presented in detail.3. Based on the analysis of the existing backoff algorithms in access layer, an adaptive slow backoff algorithm is proposed. Analysis and simulation results show that, the new algorithm can improve newwork throughput efficiently. Especially when the network congestion varies seriously, the new algorithm can reduce overhead and keep the network throughput stable.4. Based on the analysis of the existing low-duty-cycle algorithms, an adaptive duty-cycle algorithm is proposed, which concerns withstability allowance and 7 segments algorithm. Analysis and simulation results show that, the new algorithm can reduce energy consumption and idle nodes' duty-cycle, predict data throughput of next period, then adjust duty-cycle to reduce congestion. Especially when the packets burst out, the new algorithm can improve throughput effectively.5. The directions of research in this area are introduced.