A spread-specttrm CDMA communications system for locating remote units, and for communicating message data between a plurality of remote units and a base station. The spread-spectrum CDMA communications system includes a plurality of base stations and a plurality of remote units. A base station has a...http://www.google.com.au/patents/US5365544?utm_source=gb-gplus-sharePatent US5365544 - CDMA communications and geolocation system and method
