CDTS: Coordinator Data Traffic Shunt Model for Zigbee Networks

Zigbee, a wireless sensor network, is expected to have a explosive growth in the use of wireless control and monitoring applications because it has the advantages of low cost and easy deployment. As Zigbee is applied to more emerging applications, scalability becomes a critical issue: all sensor data is sent to the coordinator before forwarding to the sink node, and obviously the coordinator becomes the bottleneck. This paper proposes Coordinator Data Traffic Shunt (CDTS) performing data traffic shunt feature to reduce Coordinator’s traffic. CDTS group consists of CDTS routes and forwards data directly to Sink instead of to the coordinator. To ease CDTS router implementation without modifying Zigbee standard, CDTS layer is added between Media Access Control (MAC) and network (NWK) layers in Zigbee stack. CDTS layer intercepts packets and redirect them to the Sink node without involving the coordinator. We implement CDTS routers in TI CC2530 Zigbee platform and NS2 simulation. Experiment results demonstrates CDTS provides better packet deliver ratio and lower coordinator loading than original Zigbee stack. Thus, CDTS successfully resolves Zigbee bottleneck problem and is fully compatible with current Zigbee stack design.