Group communication system
US6445687B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 9, 1998 |
| Grant date | Sep 3, 2002 |
| Priority date | — |
| Expiry date | Jun 9, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W72/30
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A group communication system is disclosed, that comprises at least one controlling station, at least one base station connected to the controlling station through a wired circuit or a radio circuit, and a plurality of mobile stations connected to the base station, wherein the controlling station or the base station has a means for managing group communication numbers of the mobile stations, wherein the mobile stations each have a means for transmitting a mobile station identification number and a group communication number to the base station when a radio zone of each of the mobile stations is handed over and thereby a location registration operation is performed, wherein the controlling station or the base station has a zone area presence determining means for determining whether or not a particular mobile station is present in a radio zone to which the particular mobile station has been handed over when the controlling station or the base station receives the group communication number from the relevant mobile station, and wherein the base station has a means for releasing a communication channel when the relevant mobile station is not present in the radio zone as the determined …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.