The SL supervisory system
- 1 December 1984
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in Journal of Lightwave Technology
- Vol. 2 (6) , 991-997
- https://doi.org/10.1109/JLT.1984.1073699
Abstract
Long-haul transmission systems often require a supervisory system to accomplish such repeater control and monitor functions as switching in standby components and measuring performance parameters. In an undersea system, it is impractical to provide a physically separate channel on which the repeater can send and receive supervisory signals. In SL, this problem is solved by embedding supervisory signals within the main data channels in such a way that they can be extracted or added within the repeater. Supervisory commands are sent to the repeaters on a subcarrier derived by periodically switching between odd and even parity computed over blocks of data. Supervisory responses are sent from the repeaters by low-index phase modulation of the data stream. This paper details the implementation of this scheme, as well as its benefits and limitations.Keywords
This publication has 1 reference indexed in Scilit:
- Systematic Jitter in a Chain of Digital RegeneratorsBell System Technical Journal, 1963