Passive bus communication for
US4835769A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1988 |
| Grant date | May 30, 1989 |
| Priority date | — |
| Expiry date | Jan 29, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q2213/299
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An apparatus for providing passive bus communication in an ISDN without use of services of a central office includes a passive bus suitable for ISDN D-channel frame communication, the passive bus having an echo channel and having a plurality of terminal devices coupled to the passive bus. A receiving circuit is coupled to the passive bus for receiving D-channel frames containing a SAPI address transmitted from the terminal devices over the passive bus. A decoding circuit is coupled to the receiving circuit for decoding D-channel addresses transmitted from the terminal devices over the passive bus. The decoding circuit includes a circuit for determining if one of the D-channel frames from the terminal devices include a predetermined SAPI address. A switching circuit is coupled to and responsive to the decoding circuit, and implements a logical communication channel between two or more of the plurality of terminal devices when the D-channel frame includes the predetermined SAPI address. The switching circuit echoes D-channel frames over the echo channel of the passive bus for receipt by the terminal devices (TE) coupled to the passive bus and inhibits transmission of the D-channel fr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.