A wavelength division multiplexed, WDM, telecommunication system with automatic compensation of chromatic dispersion in a predetermined wavelength band, comprising a first transceiver on a transmitter side and a second transceiver on a receiver side connected to the first transceiver through an optical transmission link: 1.1 said second transceiver comprising a probe signal detection unit adapted to detect amplitude modulated probe signals, AMPS, generated by a probe signal generation unit included in the first transceiver, 1.2 the probe signal generation unit included in the first transmitter being adapted to generate the amplitude modulated probe signals, AMPS, with a predetermined relative phase difference before being transmitted by the first transceiver through the optical transmission link to said second transceiver, the probe signal generation unit including two amplitude modulated laser diodes (5A, 5B) adapted to generate the amplitude modulated probe signals, AMPS " the two amplitude modulated laser diodes (5A; 5B) having a separation in wavelengths; and 1.3 the second transceiver including a chromatic dispersion compensation unit comprising a tunable dispersion compensation module adapted to be controlled by an algorithm to completely compensate the chromatic dispersion in response to a relative phase difference of the amplitude modulated probe signals, AMPS, detected by said probe signal detection unit of the second transceiver until the relative phase difference at the second transceiver on the receiver side equals that at the first transceiver at the transmitter side; and 1.4 wherein the probe signal generation unit is adapted to tune the wavelength of at least one amplitude modulated probe signal, AMPS, to derive a sign of the chromatic dispersion, is adapted to calculate an average value of the estimated chromatic dispersion, and is adapted to change the modulation frequency of the amplitude modulated probe signals, AMPS, generated by the laser diodes (5A, 5B) at the transmitter side to increase an accuracy of the chromatic dispersion compensation, and adapted to vary a frequency spacing between probe signal wavelengths of the amplitude modulated probe signals, AMPS, generated by the laser diodes (5A, 5B) at the first transceiver on the transmitter side to increase an accuracy of the chromatic dispersion compensation. 1.1 said second transceiver comprising a probe signal detection unit adapted to detect amplitude modulated probe signals, AMPS, generated by a probe signal generation unit included in the first transceiver, 1.2 the probe signal generation unit included in the first transmitter being adapted to generate the amplitude modulated probe signals, AMPS, with a predetermined relative phase difference before being transmitted by the first transceiver through the optical transmission link to said second transceiver, the probe signal generation unit including two amplitude modulated laser diodes (5A, 5B) adapted to generate the amplitude modulated probe signals, AMPS " the two amplitude modulated laser diodes (5A; 5B) having a separation in wavelengths; and 1.3 the second transceiver including a chromatic dispersion compensation unit comprising a tunable dispersion compensation module adapted to be controlled by an algorithm to completely compensate the chromatic dispersion in response to a relative phase difference of the amplitude modulated probe signals, AMPS, detected by said probe signal detection unit of the second transceiver until the relative phase difference at the second transceiver on the receiver side equals that at the first transceiver at the transmitter side; and 1.4 wherein the probe signal generation unit is adapted to tune the wavelength of at least one amplitude modulated probe signal, AMPS, to derive a sign of the chromatic dispersion, is adapted to calculate an average value of the estimated chromatic dispersion, and is adapted to change the modulation frequency of the amplitude modulated probe signals, AMPS, generated by the laser diodes (5A, 5B) at the transmitter side to increase an accuracy of the chromatic dispersion compensation, and adapted to vary a frequency spacing between probe signal wavelengths of the amplitude modulated probe signals, AMPS, generated by the laser diodes (5A, 5B) at the first transceiver on the transmitter side to increase an accuracy of the chromatic dispersion compensation.