Patent ID: 7826745

Claim:
A method for transmitting signals from a plurality of input channels over a Time Division Multiplexing (TDM) optical network, each of said input channels containing an optical data signal and an electrical control signal containing control information relating to said optical data signal, said method comprising the steps of: converting said optical data signals to respective electrical data signals; time-division multiplexing said electrical data signals to generate a multiplexed data signal; in response to detecting a loss of an optical data signal in one of said input channels, generating an electrical control signal for said input channel indicating the loss of said optical data signal; time-division multiplexing said electrical control signals including said electrical control signal indicating loss of said optical data signal to generate a multiplexed control signal; combining said multiplexed data signal with said multiplexed control signal to generate a composite electrical signal; and converting said composite electrical signal to a composite optical signal of a particular wavelength; wavelength division multiplexing said composite optical signal with one or more other composite optical signals of different wavelengths to generate a Wavelength Division Multiplexing (WDM) composite optical signal that is transmitted over said network; and wherein in the event of said loss of said optical data signal in one of said input channels, said WDM composite optical signal includes said electrical control signal indicating loss of said optical data signal.