Channel ranking algorithm and ranking error bounds: A two channel case

In this paper, we establish a channel ranking strategy for wireless sensor networks (WSN) in the presence of WLAN interference. The packet delivery ratio (PDR) of a sensor link is the performance metric used for channel ranking. The PDR is defined as a function of the signal-to-interference-and-noise-ratio (SINR) at the sensor and the time domain transmission characteristics of the interferer that is, the activity factor and the traffic pattern. The PDR is estimated at the sensor by using spectrum measurements. When the channel bandwidth of the interferer is large and the measurement time is also limited, the traffic pattern cannot be satisfactorily predicted for each measured channel. Because of that it is proposed to utilize Poisson and periodic traffic patterns to obtain bounds on the performance of channel ranking. Given the channel measurement time upper and lower bounds on the ranking error probability are calculated by using Poisson and periodic traffic patterns respectively. Even though the traffic pattern of WLAN interference is usually modeled with phase-type (PH) distributions, the periodic and the Poisson traffic patterns allow us to bypass the traffic pattern estimation process and relatively rank the channels based on their SINR and activity factor estimates.