A communication system having a site employing a plurality of communication channels. Each channel is assigned a desired received signal strength threshold. A channel is assigned to a subscriber unit based upon the strength of the signal received at the site and the power control range of the subscriber unit. The selection of a channel may be performed either by the site or the subscriber unit. In an FDMA environment, each separate frequency division channel may be assigned different received signal strength thresholds. In a non-overlapping time interval (TDMA) environment, each separate time division channel may be assigned different received signal strength thresholds. In another embodiment, a combination of FDMA and TDMA environments can be used.