Method and system for providing a signature signal in an optical network in the event of loss of a client
US7389044B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 2005 |
| Grant date | Jun 17, 2008 |
| Priority date | — |
| Expiry date | Nov 2, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L41/06
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An optical network including multiple nodes is subject to intermittent faults that may raise alarms in the system. The invention focuses on an optical network based on the Any rate architecture. A single fault such as a client failure at a node in such a network can give rise to a loss of client signal leading to multiple alarms detected at multiple points. To alleviate this problem this invention provides switching in a special Signature signal in place of the lost client signal. By detecting the Signature signal containing a specific code, the fault on the any rate-based architecture can be uniquely identified. In addition to fault identification, the Signature signal on the network makes it possible to maintain Clock and Data Recovery Locks at downstream nodes. The Signature signal serves also as a vehicle for carrying a special optical tag called Wavekey provided by the Wavelength Tracker technology developed by the Applicant. This optical tag includes a low frequency modulation of one or more dither tones onto an optical channel, which is uniquely identified by the tag. Maintaining the Wavekey is important for tracing the end-to-end path and power level of the signal on each w…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.