Research On The ZigBee-based Wreless Sensor Network Real-time Routing Protocols

ZigBee is a kind of popular wireless personal local area network protocol standards. It is low-power, cost-effective and flexible. These characteristics contribute to its high value. Zig Bee is widely used in smart home, industrial control and environmental monitoring, etc, and researches on its application environments or needs is growing. As the real-time requirements of the wireless sensor networks increasing, researchers hope to find Zig Bee wireless sensor network protocols with low-latency and stability.Therefore, the paper makes some improvements on the existing Zig Bee routing algorithm.(1) The Cluster-Tree addressing algorithm based on neighbor table(NT-CTA)This paper introduces the research status and the existing routing algorithm, and improves the Cluster-Tree algorithm on the base of the existing Zig Bee network address and the neighbor table specification. Then the Cluster-Tree addressing algorithm based on neighbor table(NT-CTA) is proposed. The algorithm makes neighbor table as the next hop candidate sets. As the standards of calculating the remaining hop count of the current node to the destination node, the Cluster-Tree algorithm routing rules select the neighbor nodes which have the smallest number of remaining hop counts as the next hop node. To simplify the calculation of the remaining hop count, the paper proposes ancestor nodes addressing algorithm which finds the ancestor node of the destination node in different network depth according to the network address specification. The use of the algorithm can quickly identify the minimum common sub-tree root between any intermediate node and the destination node. The simulation results show that the average hop count, the average delay, and the energy consumption of the NT-CTA algorithm are better than the original algorithm, and the real-time performance is also excellent.(2)The real-time Zig Bee routing strategy based on NT-CTA algorithm(Zig Bee-RTMRS).Then the paper improves the routing process of Cluster-Tree+AODVjr algorithm based on the proposed NT-CTA algorithm. Conbining the advantages of NT-CTA algorithm and AODVjr algorithm, the paper proposes the real-time Zig Bee routing strategy based on NT-CTA algorithm. According to the Zig Bee-RTMRS, a node will check its route table first when selecting routing path. If there exists the effective entry which record the routing information to the destination node in the route table, the packet can be transmit directly. If not, the strategy will choose NT-CTA algorithm to find the path which is low in routing cost to the destination node rather than the AODVjr algorithmas, and then it will save the effective routing entry to the route table. The simulation results show that the Zig Bee-RTMRS can reduce the initial delay, especially in multi-node networks. Due to the avoidance of a series problems that arise from the form of broadcasting routing discovery, the real-time performance of Zig Bee-RTMRS is significantly better than the Cluster-Tree+AODVjr algorithm.