Passive optical network arrangement and method

A method of operating a wavelength division multiplexed (WDM) passive optical network (PON) comprising an optical line transmitter (OLT) coupled to a first optical network unit (ONU) and a second optical network unit (ONU) using an optical fiber network, the OLT comprising a first WDM transceiver arranged to transmit a received input channel to the first ONU using a first wavelength and a second WDM transceiver arranged to transmit a received input channel to the first ONU using a second wavelength, the method comprising:

• receiving a multi-cast channel and a point-to-point channel;
• using a first layer 1 (L1) switch to switchably couple the first WDM transceiver to only one of the multi-cast channel and the point-to-point channel;
• using a second L1 switch to switchably couple the second WDM transceiver to only one of the multi-cast channel and the point-to-point channel;
• receiving, with the first WDM transceiver, a first signal from the first L1 switch;
• converting the first received signal from the first L1 switch to a first optical signal having the first wavelength;
• transmitting the first optical signal having the first wavelength to the first ONU;
• receiving, with the second WDM transceiver, a second signal from the second L1 switch;
• converting the second received signal from the second L1 switch to a second optical signal having the second wavelength;
• and
• transmitting the second optical signal having the second wavelength to the second ONU.

An optical line transmitter (OLT) for a wavelength division multiplexed (WDM) passive optical network (PON), the OLT comprising:

• a first WDM transceiver arranged to receive one of a multi-cast channel and a point-to-point channel and to transmit the multicast or point-to-point channel to a first optical network unit (ONU) using a first wavelength;
• a second WDM transceiver arranged to receive one of the multi-cast channel and the point-to-point channel and to transmit the multicast or point-to-point channel to a second ONU using a second wavelength;
• a first input channel layer 1 (L1) switch having a first port connected to an input of the first WDM transceiver and having a second port connected to a source of multi-cast data and a third port connected to a source of point-to-point data, wherein the first L1 switch is operable to switchably connect either its second or third port to its first port;
• and
• a second input channel L1 switch having a first port connected to an input of the second WDM transceiver and having a second port connected to the source of multi-cast data and a third port connected to the source of point-to-point data, wherein the second L1 switch is operable to switchably connect either its second or third port to its first port, wherein
• the first WDM transceiver is configured to receive a signal from the first L1 switch, convert the received signal from the first L1 switch to a first optical signal having a first wavelength, and provide the first optical signal having the first wavelength to a first ONU,
• the second WDM transceiver is configured to receive a signal from the second L1 switch, convert the received signal from the second L1 switch to a second optical signal having a second wavelength, and provide the second optical signal having the second wavelength to a second ONU.

A wavelength division multiplexed (WDM) passive optical network (PON) comprising a first optical network unit (ONU), the first ONU comprising:

• an optical receiver for receiving a dedicated wavelength from an optical line transmitter (OLT), the dedicated wavelength carrying point-to-point or multicast input channels;
• a control signal interface arranged to send a control signal to the OLT in response to a user indication, the control signal requesting only one of point-to-point and multicast input channels;
• a second ONU, the second ONU comprising:
• a second optical receiver for receiving a dedicated wavelength from an OLT, the wavelength carrying point-to-point or multicast input channels;
• and a second control signal interface arranged to send a second control signal to the OLT in response to a user indication, the second control signal requesting only one of point-to-point and multicast input channels;
• an optical line transmitter (OLT) comprising a WDM transceiver apparatus communicatively connected to the first ONU via an optical fibre network and communicatively connected to the second ONU via the optical fibre network, wherein the WDM transceiver apparatus is operable to receive multi-cast data or point-to-point data, and wherein the WDM transceiver apparatus is arranged to transmit multi-cast data or point-to-point data to said first ONU using an optical signal having a first wavelength and is further arranged to transmit multi-cast data or point-to-point data to said second ONU using an optical signal having a second wavelength;
• an input channel switch apparatus connected to the WDM transceiver apparatus and arranged to i) selectively couple the first ONU to only one of a source of multi-cast data and a source of point-to-point data and ii) selectively couple the second ONU to only one of a source of multi-cast data and a source of point-to-point data;
• a first multiplexor having a first and second input;
• a first WDM transceiver having an output connected to the first input of the first multiplexor;
• a second WDM transceiver having an output connected to the second input of the first multiplexor;
• a first input channel layer 1 (L1) switch having a first port connected to an input of the first WDM transceiver and having a second port connected to a source of multi-cast data and a third port connected to a source of point-to-point data, wherein the first L1 switch is operable to switchably connect either its second or third port to its first port;
• and
• a second input channel L1 switch having a first port connected to an input of the second WDM transceiver and having a second port connected to the source of multi-cast data and a third port connected to the source of point-to-point data, wherein the second L1 switch is operable to switchably connect either its second or third port to its first port, wherein
• the first WDM transceiver is configured to receive a signal from the first L1 switch, convert the received signal from the first L1 switch to a first optical signal having a first wavelength, and provide the first optical signal having the first wavelength to the first multiplexor,
• the second WDM transceiver is configured to receive a signal from the second L1 switch, convert the received signal from the second L1 switch to a second optical signal having a second wavelength, and provide the second optical signal having the second wavelength to the first multiplexor, and
• the first multiplexor is configured to transmit to a second multiplexor a multiplexed signal comprising the first optical signal and the second optical signal.