Optical line terminal, optical network unit, and optical communications system

A first optical network unit (ONU), comprising:

• a downlink optical receiver, configured to receive a downlink optical signal having a wavelength of λo, and convert the downlink optical signal into a downlink electrical signal;
• an electrical de-multiplexer, configured to convert the downlink electrical signal into a high-speed downlink bit stream, and extract a target downlink bit stream belonging to the electrical de-multiplexer from the high-speed downlink bit stream, wherein at least one downlink bitstream of the high-speed downlink bitstream is associated with a management and backup channel;
• and
• a second optical modulator, configured to, after receiving an uplink bit stream and converting the uplink bit stream into a physical electrical signal, modulate the physical electrical signal into an uplink optical signal having a wavelength of λi, wherein λi is different from λt, and λt is a wavelength of another uplink optical signal received by a first optical line terminal (OLT) connected to the first ONU.

An optical communications system, comprising:

• a first optical line terminal (OLT), comprising:
• an electrical multiplexer, configured to receive downlink data frames of M1 paths, and multiplex the downlink data frames of the M1 paths into one first high-speed downlink bit stream, wherein M1 is a positive integer;
• a first optical modulator, configured to convert the one first high-speed downlink bit stream into a physical electrical signal, and modulate the physical electrical signal into a downlink optical signal having a wavelength of λo;
• N2 uplink optical receivers, wherein N2 is a positive integer greater than 1, and different optical receivers in the N2 uplink optical receivers are configured to receive uplink optical signals of different wavelengths;
• and
• N3 uplink optical receivers, wherein N3 is a positive integer, and wherein a channel in which the other N3 uplink optical receivers are located is a management and backup channel;
• a plurality of first optical network units (ONUs) including a first ONU, wherein the first ONU comprises:
• a downlink optical receiver, configured to receive a downlink optical signal having a wavelength of λo, and convert the downlink optical signal into a downlink electrical signal;
• an electrical de-multiplexer, configured to convert the downlink electrical signal into a second high-speed downlink bit stream, and extract one target downlink bit stream belonging to the electrical de-multiplexer from the second high-speed downlink bit stream;
• and
• a second optical modulator, configured to, after receiving an uplink bit stream and converting the uplink bit stream into a physical electrical signal, modulate the physical electrical signal into an uplink optical signal having a wavelength of λi, wherein λi is different from λt, and λt is a wavelength of another uplink optical signal received by the first OLT;
• and
• an optical distribution network (ODN) connecting the first OLT and the plurality of first ONUs.