A channel recovery method for RF channel failure in wireless communications systems

An RF channel at a cell is assigned to a call during the call set-up process. The channel is dedicated to the subscriber until the call is terminated (normal termination) or the subscriber leaves the cell (handoff). However, the RF channel may fail due to equipment failure or environment changes (failure-termination). In order to increase system end-to-end availability, an RF channel recovery method is proposed in this paper. When an RF channel fails, the channel is replaced by another working channel and the call continues. The method to replace failed RF channels of ongoing calls and to handle channel failures of handoff and new calls is investigated. The numerical results show that the recovery scheme reduces the dropped calls and the blocked calls significantly under both light and normal traffic. In addition, the numerical results for the recovery model and the pure performance model are nearly the same, which indicates that the recovery scheme can almost eliminate the dropped/blocked calls caused by channel impairment.