Method of measuring wavelength dispersion amount and optical transmission system

A method of measuring a wavelength dispersion amount comprising:

• a first step of transmitting a plurality of measuring signals of a wavelength bandwidth not used as a main signal, simultaneously from a first node while a line is in operation;
• and
• a second step of extracting the measuring signals at an opposing node, measuring delay times from arrival time differences of the signals, and calculating the wavelength dispersion amount from wavelength dependency of the delay times.

A method of measuring a wavelength dispersion amount comprising:

• a first step of superimposing on a main signal a pulse signal at a frequency which does not substantially influence the main signal and transmitting the signal from a first node while a line is in operation;
• and
• a second step of measuring delay times from arrival time differences of the pulse signals at an opposing node and calculating the wavelength dispersion amount from wavelength dependency of the delay times.

An optical transmission system comprising a plurality of nodes including:

• a first node for transmitting a plurality of measuring signals of a wavelength bandwidth not used as a main signal, simultaneously while a line is in operation;
• and
• an opposing node for extracting the measuring signals, measuring delay times from arrival time differences of the signals, and calculating a wavelength dispersion amount from wavelength dependency of the delay times.

An optical transmission system comprising a plurality of nodes including:

• a first node for superimposing on a main signal a pulse signal at a frequency which does not substantially influence the main signal and transmitting the signal while a line is in operation;
• and
• an opposing node for measuring arrival times of the pulse signals and calculating a wavelength dispersion amount from wavelength dependency of delay times.

A node comprising:

• first means for simultaneously transmitting a plurality of measuring signals of a wavelength bandwidth not used as a main signal while a line is in operation;
• and
• second means for extracting received measuring signals, measuring delay times from arrival time differences of the signals, and calculating a wavelength dispersion amount from wavelength dependency of the delay times.

A node comprising:

• first means for superimposing on a main signal a pulse signal at a frequency which does not substantially influence the main signal and transmitting the signal while a line is in operation;
• and
• second means for measuring delay times from arrival time differences of the received pulse signals, and calculating a wavelength dispersion amount from wavelength dependency of the delay times.