Effect of fading on thek-coverage of wireless sensor networks

In a Wireless Sensor Network (WSN), coverage performance of the network is affected by multiple factors such as source power, sensitivity of sensors, and the quality of the channel between the source and the sensors. In most existing works on WSNs, only path-loss of the wireless channel is considered, that with further assumption of absence of obstacles in the sensing region of a sensor, results in circular-type of coverage for each node. However, in some WSN applications, the channel is not line-of-sight and exhibits multipath fading. In this paper, effect of the multipath fading onk-coverage of randomly deployed WSNs is analytically investigated via techniques from stochastic geometry. More specifically, thek-coverage probability is analytically derived under Rayleigh, Rician, and Nakagami fading assumptions. Numerical results are also presented to compare the derivedk-coverage probability with the commonly usedk-coverage models that do not consider the fading effect. These results reveal the level of thek-coverage degradation due to multipath fading compared to the case of no fading (fixed range), which in some cases is shown to be very significant.