A Beacon Cluster-Tree Construction Approach For ZigBee/IEEE802.15.4 Networks

Wireless Sensor Networks (WSN) based on the IEEE 802.15.4 standard are in a constant expansion. Applications like production control, building control are more and more based on WSN because of their energy efficiency, self organization capacity and protocol flexibility. The IEEE 802.15.4 standard defines 3 network topologies: the mesh topology, the star topology and the Cluster-Tree topology. However, the construction of Cluster-Tree networks based on the beacon mode is still undefined by the IEEE 802.15.4 standard. A Beacon Cluster-Tree topology has the advantage of giving all the benefits of the Beacon mode (Synchronization, QoS support through Guaranteed Time Slots) and at the same time, allows the construction of large networks to cover large areas. In order to offer to network architects more flexibility in designing WSN, we present, in this paper, a Beacon Cluster-Tree topology construction approach. Our approach is different from what was proposed until now. We summarize our contribution in three points: (1) there are no conditions on the Beacon mode SuperFrame structure, (2) despite the size of the networks, the construction of a beacon Cluster-Tree topology is always possible and (3) no scheduling is done on SuperFrames or even on Beacon frames transmissions. Indeed, in this paper, we present a novel approach that exploits wireless receivers capability in dealing with multipath to retrieve transmitted data in order to avoid scheduling problems.