A Channel Model for the Bit Error Rate Process in 802.15.4 LR-WPAN Wireless Channels
In this work we analyze the nature of the error process in IEEE 802.15.4 low rate-wireless personal area network (LR-WPAN) channels experiencing varying levels of interference from nearby 802.11b/g networks co-habiting the unlicensed 2.4 GHz industrial-scientific-medical (ISM) band. The entire analysis is performed on a set of residual bit error traces, the data collection methodology for which is described in detail. These traces allow us to identify individual bit positions in a received packet that were in error. We use lagged phase space analysis, a technique commonly used in the analysis of chaotic systems. The analysis uncovers the stable nature of the BER process during short bursts. This simple behavior of the bit error rate (BER) can be captured by three parameters; the burst length of consecutive good packets, bad packets, and the distribution with which different BERs occur. Using collected residual bit error traces, we model the BER process by estimating the probability distributions of its parameters using maximum likelihood estimates (MLE).