Fixed cellular technical with a distinctive dial tone to indicate an emergency call is being placed
US5680439A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1995 |
| Grant date | Oct 21, 1997 |
| Priority date | — |
| Expiry date | Apr 28, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W76/50
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Of special application in cellular mobile networks that communicate this terminal, via radio, with a base station to provide services of voice and/or data communications to a number of subscribers and which, in addition to the basic communications service, also support an emergency call service performed through the terminal in question by dialling a certain number. This terminal comprises means (41) for generating user signalling tones and which also generate an emergency call dial tone, different from the other tones already present, when a call process is initiated by the subscriber (5) in the case where the fixed cellular terminal is only capable of making emergency calls.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.