Cluster Reformation and Scheduling for Interference Mitigation in Coexistence Heterogeneous Wireless Packet Networks

The emerging IEEE 802.15.4 (Zigbee) standard is designed for low data rate, low power consumption and low cost wireless personal area networks (WPANs).In ubiquitous networking environments; we generally need two or more heterogeneous communication systems coexisting in a single place. Especially, wireless local area networks (WLANs) based on IEEE 802.11b specifications and wireless personal area networks (WPANs) based on IEEE 802.15.4 specifications need to coexist in the same Industrial, Science and Medial (ISM) band. If the WPAN communication coverage is expanded using a cluster-tree network topology, then the 802.15.4 network is more susceptible to interference from neighboring WLANs. In this paper, we propose an adaptive transmission power aware cluster reformation and scheduling algorithm using multiple channels in a WPAN in the presence of WLAN interference. The algorithm includes node identification, channel allocation, cluster reformation and time scheduling. To evaluate the performance of the proposed algorithm, the performance metrics such as Packet Error Rate (PER), Throughput, Average End-End Delay and Average Jitter is measured through Qualnet simulation. PER is calculated from bit error rate. The simulation results are compared with the conventional TDMA scheme. The measurement result shows that the proposed algorithm is effective in an IEEE 802.15.4 cluster-tree network in the presence of multiple IEEE 802.11 interferers