Protection switching system for carrier transmission line
US4680776A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 9, 1984 |
| Grant date | Jul 14, 1987 |
| Priority date | — |
| Expiry date | Nov 9, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/74
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A line protection switching system of improved reliability decreases the time for protection line switching. In order to increase reliability, service signals are sent in parallel via a plurality of transmission lines, using a service bit area of PCM bit frames. The system switches a failed transmission line to a stand by line, at a local station where trouble is detected without waiting for the switching of an opposite station. At the same time, a switching command is sent to the opposite station. If the switching of the opposite station fails, the local station commands a retry of the switching operation. If it again fails, the local station returns the transmission line to the initial state. In addition, a low priority signal is transmitted through the stand by line, so that the total system operates more economically.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.