Method and apparatus for measuring and estimating optical signal to noise ratio in photonic networks
US6907197B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 2001 |
| Grant date | Jun 14, 2005 |
| Priority date | — |
| Expiry date | Nov 19, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J14/02
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A WDM optical network comprising a plurality of nodes has a first apparatus for optical analysis at the site of a first optical amplifier upstream of the first node, a second apparatus for optical analysis at the site of a second optical amplifier at the downstream output of the first node, and a third apparatus for optical analysis at the site of a third optical amplifier further downstream of the first node, where knowledge of the optical sin to noise ratio (OSNR) is desired. The first, second and third apparatus are for measuring the signal level at frequencies both at and in-between the channel frequencies. The signal levels at the channel frequencies and between the channel frequencies at the first, second and third apparatus are used to derive the OSNR at the third apparatus. This enables the OSNR to be measured accurately at any site in the network, using calculations in which noise shaping of the nodes can be factored in to the calculation of OSNR.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.