An optical line terminal (OLT) comprises a target OLT channel termination (CT), and a source OLT CT in communication with the target OLT CT, wherein the source OLT CT is configured to exchange tuning messages with the target OLT CT to initiate upstream wavelength tuning of an optical network unit (ONU), wherein the source OLT CT is configured to transmit a tuning request to the ONU after the tuning messages have been exchanged and to receive a tuning acknowledgement message from the ONU indicating that the tuning request will be executed, wherein the source OLT CT is configured to transmit a broadcast notification message to all OLT CTs within the OLT, except for the source OLT CT, after receipt of the tuning acknowledge message from the ONU, and wherein the broadcast notification message includes a tuning time of the ONU.

An optical line terminal (OLT) comprises a target OLT channel termination (CT), and a source OLT CT in communication with the target OLT CT, wherein the source OLT CT is configured to exchange tuning messages with the target OLT CT to initiate upstream wavelength tuning of an optical network unit (ONU), wherein the source OLT CT is configured to transmit a tuning request to the ONU after the tuning messages have been exchanged and to receive a tuning acknowledgement message from the ONU indicating that the tuning request will be executed, wherein the source OLT CT is configured to transmit a broadcast notification message to all OLT CTs within the OLT, except for the source OLT CT, after receipt of the tuning acknowledge message from the ONU, and wherein the broadcast notification message includes a tuning time of the ONU.

A remote node device for mutual communication between optical network units in a passive optical network includes an NN-arrayed waveguide grating configured to receive upstream optical signal of one of the optical network units and to output this signal as a first optical signal; a 12 wavelength division multiplexer configured to separate per band the first optical signal to obtain a second optical signal; and a 1(N1) power distributor configured to transmit the second optical signal to the corresponding optical network unit through the NN-arrayed waveguide grating.