A two-way messaging system (100) having a plurality of message subscriber units (500) and a base station (220) in each of a plurality of cells (210). The base station has a transmitter (224) for transmitting messages in an associated cell (210) and a receiver (228) associated therewith for receiving...http://www.google.com.hk/patents/US5649289?utm_source=gb-gplus-share專利 US5649289 - Flexible mobility management in a two-way messaging system and method therefor
