ITU/TDD modem
US5687222A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1996 |
| Grant date | Nov 11, 1997 |
| Priority date | — |
| Expiry date | Jul 19, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/066
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A communication system includes an ITU/TDD/VOICE modem that is connected to a local computer and a telephone line. The ITU/TDD/VOICE modem allows transmission and reception of ITU, TDD, and voice signals over the telephone line to and from a remote device. Examples of remote devices include a remote TDD or ITU modem (which connects to a remote computer), or a telephone. The ITU/TDD/VOICE modem may operate in various modes including (1) a computer communications mode and (2) a stand alone mode. During computer communications mode, the ITU/TDD/VOICE modem is controlled by the local computer. During stand alone mode, the ITU/TDD/VOICE modem operates independently of the local computer. The stand alone mode may further include an answering machine mode and prestored outgoing message mode. The ITU/TDD/VOICE modem includes various other features including one or more of the following: a particular utilization of the transmit/receive LED's in TDD mode; the ability to reacquire a new ITU or TDD connection from TDD mode (i.e., reacquisition mode); techniques for minimizing answer tone duration; techniques for modem status query; techniques for silencing Baudot or ITU modulation during voice…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.