US 4,449,247 A · Local orderwire facility for fiber optic communication system

Abstract

An orderwire communication scheme for a fiber optic communication network includes terminal station equipment associated with the central offices at opposite ends of the network and signal regenerator equipment at the repeater sites disposed between the terminal stations. The communication format along the link is a data-over-voice scheme, the data being digitally encoded on an FSK modulated carrier. In carrying out supervisory functions with respect to each of the stations along the link, command messages are conveyed from the terminal stations at one of the central offices to respective stations along the link in the form of command instructions. Each command message from a central office's terminal station contains the address of the recipient station for whom the message is intended followed by a specific encoded instruction. The instruction may contain a request for information from the addressed site as to equipment conditions at the side and/or a directive that the equipment at the site perform a particular task. In reply to the command message sent to it, the addressed site transmits a response message back to the source station, representative of the status of a particular equipment condition or operation as requested by the command instruction. In this manner, supervisory personnel at each central office may remotely monitor and control the operation of the commuication equipment at the various sites along the link and thereby take correction maintenance or protection channel substitution action where and when required. The digital message transmission scheme also provides facility for fault/alarm reporting, testing the bit error rate of individual channels of the repeater and the transceiver equipment at each terminal station when requested, and is used for paging signalling between central offices.

Claims20

Dependent claims

In a data scrambler in which incoming data is subjected to a prescribed scrambling code so as to produce an output scrambled data sequence, an arrangement for preventing said scrambler from locking into a continuous state comprising:

first means, coupled to said scrambler, for comparing selected contents of said scrambler with incoming data to be scrambled;
and
second means, coupled to said first means and disposed in the data flow path between said incoming data and said scrambler, for altering the data to be coupled into said scrambler, in response to said first means detecting a potential lock condition.

A communication system wherein information signals are to be conveyed along a plurality of stations disposed along a shared communications link, said link having a first portion for carrying messages in a first direction along said link and a second portion for carrying messages in a second direction along said link, each of said stations having input/output devices that may be impacted by messages carried over said link, comprising:

a first terminal station coupled to said link and having a transceiver for transmitting outgoing messages over said first portion of said link to stations along said link and receiving incoming messages transmitted over said second portion of said link;
a second terminal station coupled to said link for transmitting outgoing messages over said second portion of said link and receiving incoming messages transmitted over said first portion of said link;
and
a plurality of repeater stations coupled to said first and second portions of said link;
and wherein
each station is identified by a prescribed code unique to that station and includes means, responsive to a fault condition thereat, for repeatedly transmitting said code as an outgoing message over said first and second portions of said link.

3 more elements

For use in a communication system having a plurality of communication channels over which communication signals are conveyed between terminal stations disposed at opposite ends of said system and a plurality of repeater stations distributed between said terminal stations, and an associated orderwire system for conveying messages among said stations relating to the operation of said communication system, said orderwire system including a shared orderwire signal transmission link for carrying orderwire messages among said stations,

an arrangement for monitoring the transmission performance of selected ones of said communication channels comprising:
first means, disposed at one of said terminal stations, for transmitting a command message over said orderwire transmission link to the terminal station at the opposite end of said systems to cause a first selected communication channel to be looped at said opposite terminal station back over a second selected communication channel carrying communication signals to said one terminal station;
second means, disposed at said one terminal station, for transmitting a prescribed test signal over said first selected communication channel so as to be looped back from said opposite terminal station over said second selected communication channel to said one terminal station;
and
third means, disposed at said one terminal station, for monitoring the quality of said test signal as looped back from said first selected communication channel and received over said second selected communication channel.

2 more elements

Dependencies are inferred from the claim text.

Local orderwire facility for fiber optic communication system

Life of this patent

Local orderwire facility for fiber optic communication system

Life of this patent

Abstract

Claims20