Patent ID: 9455781
Filing Date: 2016-09-27
CPC Classification: H04B,H04J

Claim Text:
1. A method for determining whether a configuration of an optical transmission interface of a first device has to be adjusted for transmitting an optical signal to a second device, the method comprising a monitoring device performing: receiving, from the second device, information representative of instants at which extremes of signal strength are detected by the second device in at least two successive symbols of the optical signal received by the second device from the first device, wherein the optical signal is transmitted by the first device to the second device via an optical band-pass filter, the second device includes an optical reception interface configured to receive optical signals output by said optical band-pass filter and transmitted by the first device on a carrier frequency when said carrier frequency is in the passband of the optical band-pass filter; determining at least one time period between said instants at which the extremes of signal strength are detected in the at least two successive symbols of the optical signal; obtaining information representative of a time drift on the basis of the determined at least one time period, said time drift being due to a frequency shift between the carrier frequency and a nominal frequency of the optical pass-band filter, the information representative of the time drift being obtained by checking whether the at least one time period decreases compared with a reference time period duration, remains stable compared with a reference time period duration, or increases compared with a reference time period duration; determining whether the configuration of the optical transmission interface of the first device has to be adjusted, on the basis of the information representative of the time drift; and adjusting said configuration when the time drift exhibits a time period increase between the extremes of signal strength.