Adaptive Preamble Padding with Retransmission Control for ZigBee network under Wi-Fi interference

The low-power, low-rate ZigBee wireless sensor networks are vulnerable to the interference of collocated Wi-Fi wireless local area networks (WLAN). The results acquired through our extensive experimental studies on ZigBee-WLAN coexistence indicate that ZigBee connections may experience severe packet losses, caused by combined effect of interference and relatively long receive to transmit (RX-TX) turnaround time in ZigBee devices, even when the Wi-Fi and ZigBee devices are able to detect each other's signal and apply CSMA/CA algorithm accordingly. This paper proposes a novel Adaptive Preamble Padding with Retransmission Control (APPRC) technique for ZigBee devices to address this issue, meet certain packet loss rate (PLR) requirement, and improve packet transmission efficiency when they are suffering time varying interference from the collocated WLAN. The experimental performance evaluation results showed that the proposed APPRC technique can achieve significantly higher transmission efficiency while satisfying PLR requirements of sensing applications than packet retransmission. The technique described in this paper is patent pending.