Trunked communication system true priority channel scan
US4716407A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1986 |
| Grant date | Dec 29, 1987 |
| Priority date | — |
| Expiry date | Dec 19, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W84/08
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
While receiving a lower priority message, a remote transceiver unit in a trunked radio communication system is diverted immediately to a priority channel when a priority message is generated. In a first embodiment, a low speed, sub-audible sync word, transmitted by a system controller, causes the remote transceiver to momentarily interrupt the current message and receive priority data transmitted by the system controller. If the priority level of the priority messages exceeds that of the current message, it immediately switches to the priority channel. If not, the remote transceiver reverts to its normal receiving mode and continues its original communication. In a second embodiment, the priority data is transmitted entirely sub-sudible so as to not interrupt the current message. Lastly, in a more basic embodiment, a sub-audible word is transmitted to the remote units causing them to revert to the control channel to receive the priority call assignment. Multi-level message priority is also provided by transmitting sequential priority data words which identify calls of varying priority. The remote units may then respond to the highest priority call.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.