Patent ID: 8218966
Filing Date: 2012-07-10
Classification: H04B

Abstract:
1. A method for securing transmission of data via an optical communication line comprising a first optical fiber extending between a first network element and a second network element, the method comprising: conveying a first optical signal carrying said data via the first optical fiber from the first network element towards the second network element at a predetermined optical wavelength; conveying a second, disruptive interference optical signal via the first optical fiber at the same predetermined optical wavelength in the opposite direction to create within the first optical fiber a combined optical signal at said predetermined optical wavelength, so that said combination of said first and second optical signals hampers an unauthorized non-intrusive extraction of the first optical signal from said combined optical signal, the method further comprising the following operations: from time to time switching transmission of the first optical signal to carry said data at another predetermined optical wavelength, without changing direction of its transmission; from time to time switching transmission of the second optical signal to said another predetermined optical wavelength, without changing direction of its transmission, wherein the switching of the second signal is synchronized with the switching of said first signal.