| 摘要 |
<p>Base transmitters (116) of a wireless messaging system are pre-programmed (802) with location identifiers (216) for identifying the positions at which the base transmitters are located. In response to an inbound message form a portable subscriber unit (122), a fixed portion (102) of the wireless messaging system makes an estimate (808) of a location at which the portable subscriber unit is positioned A controller (112) sends (812) and outbound message (614) and the estimate to the base transmitters, and the base transmitters calculate (812) distances between themselves and the portable subscriber unit, based upon the location identifiers and the estimate. In addition, the base transmitters independently make a decision (818) whether to transmit the outbound message, based upon a comparison of a predetermined rule with the distance of the base transmitter from the portable subscriber unit.</p> |
