Protective Dummy-byte Preamble Padding for improving ZigBee packet transmission under Wi-Fi interference

Recent studies have shown that the low-power ZigBee based wireless sensor networks (WSN) are vulnerable to the interference generated by nodes of Wi-Fi wireless local area networks (WLAN). Mutual interference can be mitigated at nodes of either technology when energy detection (ED) is enabled in clear channel assessment (CCA). From our experimental studies on ZigBee and Wi-Fi coexistence issue, it is determined that a significant amount of ZigBee packet losses occur due to the Wi-Fi interference induced corruption of the physical layer header of ZigBee packets, which could happen even when the ED mechanisms of the Wi-Fi and ZigBee devices are able to detect each other´s signal and CSMA/CA algorithms are applied accordingly. To study this phenomenon, a series of experiments were carried out, followed by thorough analysis of the recorded data. The study led to the design of a simple but effective technique named Protective Dummy-byte Preamble Padding (PDBPP) that improves the performance of ZigBee packet transmission in terms of packet loss rate (PLR) and transmission efficiency. The experimental performance evaluation results confirmed the effectiveness of PDBPP in improving PLR and transmission efficiency of a ZigBee network exposed to interference generated by collocated WLAN. Some material in this paper is part of a pending patent.