Cordless telephone apparatus which restores radio channels after power loss
US5426690A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1993 |
| Grant date | Jun 20, 1995 |
| Priority date | — |
| Expiry date | Jul 30, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/70
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A cordless telephone apparatus detects the received field strength in a receive channel, as viewed from the base unit side, and if the field strength is below a prescribed level outputs an out-of-range signal on a receive channel, as viewed from the base unit side. The remote unit is provided with a volatile memory area for storing channel connection state data indicating whether or not two-way radio communication was established between the remote unit and the base unit. A backup power source enables the contents of the volatile memory area to be maintained even if there is an interruption in the supply of power from the battery in the remote unit. A call resumption control circuit to resume transmission of call information from the remote unit when internal power in the remote unit is supplied from the battery. The data in the volatile memory area indicating the channel connection state indicates whether two-way radio communication was established, and also detects an out-of-range signal transmitted from the base unit side.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.