DIRECTIONAL OPPORTUNISTIC MECHANISM IN CLUSTER MESSAGE CRITICALITY LEVEL BASED ZIGBEE ROUTING

The cluster message criticality level based zigbee routing(CMCLZOR) has been proposed for routing the cluster messages in wireless smart energy home area networks. It employs zigbee opportunistic shortcut tree routing(ZOSTR) and AODV individually for routing normal messages and highly critical messages respectively. ZOSTR allows the receiving nodes to compete for forwarding a packet with the priority of left-over hops rather than stating single next hop node like unicast protocols. Since it has inherited benefits of both opportunistic routing and ZSTR, it can offer reliable packet delivery service without any resources for unicast routing and forwarder candidate selection for opportunistic routing. However, ZOSTR has many forwarder candidates on a path in a lossy wireless environment despite the failure of particular node on a path. To detach the out-of-sight forwarder candidates from routing, this paper proposes zigbee directional opportunistic shortcut tree routing (ZDOSTR). It confines the forwarder candidates space along the direction towards the destination to forward the packet by forwarder candidates with minimum left-over hops of single-hop neighbors. The performance evaluation shows that the directional opportunistic approach considerably improves different network performances than ZOSTR by suppressing replicas from out-of-sight terminals efficiently. Thus, this paper also proposes directional opportunistic CMCLZR(CMCLZDOR) that replaces ZOSTR by ZDOSTR for routing normal messages.