Wavelength division optical signalling network apparatus and method

A terminal station for an optical communications system utilising a plurality of data transmission wavelengths, the terminal station comprising:

• means for sending a data signal on one of the free data transmission wavelengths,
• means for selecting said one data transmission wavelength from among a plurality of the data transmission wavelengths,
• control signal sending means for sending a control signal indicative of the destination of said data signal on a common signalling channel receivable by a plurality of other terminal stations in the system,
• an input port for receiving said plurality of data transmission wavelengths, and
• said sending means comprising at least one light modulator device connected to said input port to receive said free data transmission wavelength, and to modulate said free data transmission wavelength with data.

A terminal station for an optical communications system utilising a plurality of data transmission wavelengths, the station comprising:

• data sending means for sending data on at least one, but not all, of the data transmission wavelengths simultaneously, said data sending means including at least one modulator for modulating a received light signal,
• a non-tunable wavelength separator for spatially separating the data transmission wavelengths from a wavelength multiplexed input to a plurality of spatially separate wavelength paths each having a fixed correspondence to one of said wavelengths,
• routing means for selectively coupling the data sending means to one of said wavelength paths, and
• combining means for recombining the output of the data sending means with the other wavelengths.

A terminal station for an optical communications system utilising a plurality of data transmission wavelengths, the station comprising:

• data receiving means for receiving data on at least one, but not all, of the data transmission wavelengths simultaneously,
• a non-tunable wavelength separator for spatially separating the data transmission wavelengths from a wavelength multiplexed input to provide a plurality of separate wavelength paths each having a fixed correspondence to one of said wavelengths,
• routing means for selectively coupling the data receiving means to one of said wavelength paths, and
• combining means for recombining the output thereof with the other wavelengths.