Trunked radio repeater system with multigroup calling feature
US5274837A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1992 |
| Grant date | Dec 28, 1993 |
| Priority date | — |
| Expiry date | Mar 30, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/06
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A digitally trunked radio repeater system provides substantial improvements in timeliness of channel acquisition and channel drop, and in reliability of critical control signalling. The system uses a much higher digital signalling rate than is typically found in prior art systems, and uses a control channel to convey digital channel request and assignment messages between the central site and mobile transceivers. The mobile radio transceivers transmit channel requests on the control channel (if no response is received, the mobile retries during a retry time window which increases in duration in dependence on the number of retries). The mobile transceiver switches to a working channel in response to an assignment message received on the control channel. Subaudible digital signals transmitted on the control channel and on active working channels allow late entry, shifting to higher priority calls, and other advanced functions. Message and transmission trunking capabilities are both present so as to maximize working channel usage without compromising channel access for high priority communications. During transmission trunking, called and calling transceivers return to the control cha…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.