Installation with portable, wireless telephone sets
US4731812A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 19, 1986 |
| Grant date | Mar 15, 1988 |
| Priority date | — |
| Expiry date | Dec 19, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W84/14
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In an installation containing at least one stationary unit (5) with a radio transmitter and a radio receiver, both with short range, and at least one, and preferably several portable, wireless telephone sets (4) with a radio transmitter and a radio receiver, both with short range, for exchanging telephone messages with one of the stationary units in the installation (1, 2, 3) the stationary units (5) are each adapted to exchange telephone calls simultaneously with more than one portable telephone set (4) on radio speech channels, adaptively selected among a plurality of radio speech channels common to all radio transmitters (9, 31) and radio receivers (10, 32). There is also included a radio exchange (6) to which the stationary units (5) are connected, this radio exchange being adapted to switch a telephone call having decreasing intelligibility between a portable telephone set (4B) and a first stationary unit (5A) to a telephone call with increasing intelligibility between the same portable telephone set and a second stationary unit (5B). A compressor (20, 41) coacts with each of the radio transmitters (9, 31) for time-compressing the speech signals, and an expander (12, 42) coact…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.