Performance Evaluation of IEEE 802.15.4 Protocol Under Coexistence of WiFi 802.11b

ZigBee (IEEE 802.15.4) is a wireless mesh networking protocol low in cost, power, data rate, and complexity. To access Lo- cal Area Networks (LAN), 802.11b/g standard is used all over the world as Wi-Fi (Wireless Fidelity) standard. IEEE 802.15.4 Wireless Sensor Networks (WSNs) and IEEE 802.11b/g Wireless Local Area Networks (WLANs) are often collocated, causing a coexistence. The coexistence occurs because these networks share the same 2.4 GHz Industrial, Scientific, and Medical (ISM) band. A Simulation model has been introduced which completely reflects the ZigBee and WiFi coexistence. We have proposed frequency agility based interference avoidance algorithm. However, algorithm detects interference and adaptively switch nodes to safe channel for dynamically avoid WLAN interference with lower latency and energy consumption. The performance of ZigBee under WiFi is empirically evaluated in terms of the packet error rate (PER) and bit error rate (BER). The Simulation results us- ing frequency agility algorithm demonstrate that the design guideline can efficiently mitigate the effect of WiFi interference and enhance the performance of ZigBee networks.