Study on IEEE802.15.4 Link Reliability in Industrial Environment

As the first step of the WSN protocol design, such as MAC layer and Network layer, in-depth investigation on link characteristics is very important. In the industrial environments, link reliability is vulnerable to various interferences. Therefore, many schemes have been employed for reliability improvements, e.g. frequency diversity, path diversity etc., which put forward the demand on link reliability model. However, there has been little work modeling the temporal and frequency variations of the link reliability. The contributions of this paper are modeling the link characteristics of IEEE802.15.4 radio transceiver on all 16 channels based on Packet Drop Rate (PDR) data sets collected in typical factories and a link layer reliability model (LLSM), which focuses on the quantitative relationships among link reliability, time and frequency. It is found that the PDR in a certain range follows logistic or log-logistic distribution, and the interval of two sequential failed in Packet Drop Sequence (PDS) follows log-normal distribution. The model is implemented as simulation framework component and used to evaluate the influence on frequency diversity design by the simulation of two proposals of IEEE 802.15.4e.