Communication system for converting
US5278972A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1990 |
| Grant date | Jan 11, 1994 |
| Priority date | — |
| Expiry date | Nov 21, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q2213/22
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A communication system operates compatibly with a public or private switching network using a Q.931 protocol for basic rate ISDN communications. Communications between a control unit and station terminals of the system use a local protocol which is a modification of the Q.931 protocol. This local protocol includes one segment including the mandatory elements of the Q.931 protocol and a second segment derived by converting the optional elements of the Q.931 protocol into a local codeset which controls the user interface circuits at each station terminal. The local protocol enables call control between the control unit and each station terminal to be managed on a bearer channel basis while call control between the system and the network is managed on a call appearance basis using the standard Q.931 protocol. The local protocol provides for communicating line selection and feature activation commands from the terminal to the control unit, using simple button commands.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.