Patent ID: 7555213

Claim:
A method of determining whether there is a break in an optical fiber cable of a telecommunications network between a first point and a second point of the optical fiber cable, comprising the steps of: connecting to the first point of the optical fiber cable an optical component; configuring the optical component to be a receive erbium doped fiber amplifier (EDFA); connecting to the second point of the optical fiber cable an optical time domain reflectometer (OTDR) operative for emitting OTDR signals along the optical fiber cable towards the optical component, introducing at least one optical signal into the optical fiber cable at the first point thereof after a break in the optical fiber cable is suspected by arranging the receive EDFA to introduce the at least one optical signal into the optical fiber cable and by controlling isolation of an input isolator of the receive EDFA such that, in the absence of an input signal thereto. the at least one optical signal in the form of amplified spontaneous emission noise escapes from an input of the receive EDFA and is introduced into the optical fiber cable; using the optical fiber cable to carry the at least one optical signal to the second point thereof; and configuring the OTDR to detect the at least one optical signal from the optical fiber cable and to prevent emission of the OTDR signals at any time during which detection of the at least one optical signal occurs.