基于ZigBee技术无线传感器网络节点研究

Research of Nodes for ZigBee-Based Wireless Sensor Networks

目的设计低功耗网络节点、减少数据包的丢失和避免数据间的竞争和冲突,提高网络节点生命周期.方法从IEEE802.15.4通信层所定义的介质接入控制子层(MAC)和物理层出发,对物理层的功耗和数据流量、功耗和吞吐率之间的关系及其MAC协议的通信距离和灵敏度之间的关系和RSSI与丢包率之间的关系分别进行了仿真验证,并进一步对功耗和发包间隔、功耗和时延之间的关系进行了仿真验证.结果减少数据流量是在物理层协议中解决节能方面的最有效方案;随着通信距离的增大,灵敏度也逐渐减小的趋势,RSSI处在-87 dBm～-93 dBm之间时,丢包率显著增长.短距离传输可以减小数据包丢失;发包间隔增大、时延增大可以避免大量数据之间的竞争和冲突.结论研究表明短距离、发包间隔大和时延长非常适合大量节点的数据传输.研究结果对解决基于ZigBee技术无线传感器网络节点的节能、数据包的丢失、数据之间的竞争和冲突具有重要的意义.

Designing a low-power network node, reducing the losing of the datagram and avoiding the clash between the data are the keys for improving the lifecycle of the network node. For resolving the above prob- lem effectively, the relation between power consumption and data traffic of physical layer, between the power consumption and system throughput, between distance of communications and sensitivity of MAC and be- tween RSSI and Packet Loss Rate are simulated from physical layer and MAC of the communication layer of IEEE802. 15.4. Reducing the data traffic of nodes is the most effective plan on resolving energy efficient; the sensitivity is reduced with the increasing of communications distance;the packet loss rate grows signifi- cantly at the time of the value of RSSI between - 87dBm and - 93 dBm; the losing of the datagram can be reduced by short-distance transmission;increasing the interval of sending packets and transmission delay of data transmission of nodes can avoid the clash between large amounts of data. The results show that short distance, large interval of sending packets and long transmission delay are appropriate for the transmission of large amounts of data of nodes. The results are very helpful for resolving the energy conservation of wirelesssensor network node, the losing of the datagram and the clash between large amounts of data.