Optical network unit, central office node and methods of configuring an optical network unit

A central office, CO, node for a passive optical network, PON, the CO node comprising:

• a plurality of optical line terminations, OLTs, operable at respective channel wavelengths of a PON, one of the OLTs being allocated to a control channel;
• and
• a controller comprising at least one processor and memory containing instructions executable by the at least one processor whereby the CO node is operative to:
• allocate the channel wavelengths to ONUs of the PON;
• and
• transmit, on a downstream control channel signal from the allocated OLT at a downstream control channel wavelength, an indication of the allocation of channel wavelengths to ONUs of the PON.

A method of configuring an optical network unit, ONU, of a passive optical network, PON, the ONU, comprising a tunable transmitter and a tunable receiver, the method comprising steps of:

• if the tunable transmitter is on, switching the tunable transmitter off and if the tunable receiver is off, switching the tunable receiver on;
• determining a downstream control channel wavelength;
• setting an operating wavelength of the tunable receiver to the downstream control channel wavelength;
• receiving a downstream control channel signal at the downstream control channel wavelength from a central office, CO, node of the PON, the downstream control channel signal carrying an indication of an allocation of channel wavelengths to ONUs;
• obtaining allocated downstream and upstream channel wavelengths for the ONU from the indication of an allocation of channel wavelengths to ONUs;
• setting an operating wavelength of the tunable receiver to the allocated downstream channel wavelength and setting the operating wavelength of the tunable transmitter to the allocated upstream channel wavelength;
• and
• switching the tunable transmitter on.