Hamidreza Tavakoli - Department of Electrical Engineering, Hakim Sabzevari University, Sabzevar, Iran

In this paper, we investigate the lifetime of the network which is composed of a number of interconnected IEEE802.15.4 network clusters in which ordinary nodes have the role of bridge nodes. Bridge operation consists of atransmission to the coordinator node known as CSMA-CA uplink transmission and a transmission to the bridge nodeknown as CSMA-CA downlink transmission. Using the above mechanism, a bridge node periodically communicateswith the neighboring clusters. Using queuing model and probabilistic analysis we present performance results in whichthe effects of changing different parameters i.e. number of clusters and number of bridges are investigated. Our analysisdetermines how affecting parameters should be changed in order to extend network lifetime. Our results also show fairdistribution of energy consumption of nodes which implies that all nodes of a cluster will deplete their energy withinshort interval of time.

IEEE 802.15.4 beacon-enabled mode, slave-slave Bridge, sensing reliability, coefficient of variation, skewness, network lifetime, wireless sensor networks