Abstract: A wireless communications system is described for subscribers scattered at distances of up to 40 km. Wireless access for subscribers is provided from wireless base-stations (WBS) that are connected to a PSTN access node 16 via T1 links. These links support the subscriber traffic, and also provide network management. Where, due to terrain, the whole area can not be served from a single WBS site, additional WBS may have to be installed to provide fill-in coverage. However, all WBS in the coverage area are connected to the same PSTN access node. A wireless loop air interface structure consists of 2304 bits per 4 milliseconds divided into an outbound portion and an inbound portion with a gap of 48 bits between. The communications air interface uses a Frequency Hopping Spread-Spectrum (FHSS) air interface as specified for the 2.4-2.4835 GHz ISM band. The FCC regulations for occupied channel avoidance FH are given in 47CFR2.47(h). The intelligent adaptation of the FH code used by each WBSR follows this regulation.