Method of generating an alert for walkie-talkie when out of communicatable distance
US6816070B1 · kind B1 · utility
9Cited by
4References
2Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 22, 2003 |
| Grant date | Nov 9, 2004 |
| Priority date | — |
| Expiry date | Apr 22, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/1027
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method of generating a warning signal for a walkie-talkie includes: providing a detector and a timer; using the timer to count time; using the detector to determine whether the strength of a radio frequency (RF) signal which includes a standard CTCSS tone received by the walkie-talkie is larger than a predetermined value; using the detector to determine whether the strength of a RF signal which includes a non-standard CTCSS tone received by the walkie-talkie is larger than the predetermined value; if so, resetting the timer; and issuing a warning signal when the time counted by timer reaches a predetermined time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.