A method of establishing communication between an optical line terminal and an optical network unit within an optical access network includes receiving a signal indication from an optical transceiver of an optical line terminal. The signal indication includes: (i) a loss-of-signal indication indicating non-receipt of an upstream optical signal from the optical network unit; or (ii) a signal-received indication indicating receipt of the upstream optical signal from the optical network unit. The method includes determining whether the signal indication includes the loss-of-signal indication. When the signal indication includes the loss-of-signal indication, the method includes instructing the optical transceiver to cease signal transmission from the optical transceiver to the optical network unit. Moreover, when the signal indication includes the signal-received indication, the method includes instructing the optical transceiver to transmit a downstream optical signal from the optical transceiver to the optical network unit.

Disclosed is an optical line terminal (OLT), including: N tunable modules, each of the N tunable modules include M tunable transmitters, the number of tuning channels of the M tunable transmitters is greater than or equal to two and the number of the tuning channels is less than MN, wherein N and M are integers greater than or equal to two.

A channel adjustment method, apparatus and system. The method includes: an optical line terminal (OLT) receives a channel binding capability parameter reported by an optical network unit (ONU) and supported by the ONU; the OLT determines a channel binding capability parameter of a to-be-bound channel of the ONU according to the channel binding capability parameter, a serving application of the ONU and/or a data transmission state; and the OLT sends, to the ONU, first binding control information carrying the channel binding capability parameter of the to-be-bound channel of the ONU and used for instructing the ONU to adjust the bound channel.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for reducing jitter and latency in a PON. In one aspect, an optical network unit includes a downstream optical receiver configured to receive downstream traffic over a first wavelength; a first upstream optical transmitter having a first data rate; a second upstream optical transmitter having a second data rate that is higher than the first data rate; and a controller configured to direct upstream traffic to one of the first upstream optical transmitter or the second upstream optical transmitter depending on a traffic type of the traffic. Traffic having a control plane traffic type is directed to the first upstream optical transmitter and traffic having a data plane traffic type is directed to the second upstream optical transmitter.

In one embodiment, a first group of splitters receives a group of signals from a group of transmitters. Each splitter in the first group of splitters splits a signal into a plurality of signals that are sent to a plurality of multiplexers. A multiplexer in the plurality of multiplexers receives one of the plurality of signals from each splitter in the group of splitters and multiplexes the received one of the plurality of signals into a multiplexed signal. The multiplexer sends the multiplexed signal through a single connection in which upstream signals are sent to a group of nodes and downstream signals are received from the group of nodes. A de-multiplexer de-multiplexes the multiplexed signal into the group of signals and sends the group of signals to the group of nodes via a second group of splitters that are connected to the group of nodes.

A method of establishing communication between an optical line terminal and an optical network unit within an optical access network includes receiving a signal indication from an optical transceiver of an optical line terminal. The signal indication includes: (i) a loss-of-signal indication indicating non-receipt of an upstream optical signal from the optical network unit; or (ii) a signal-received indication indicating receipt of the upstream optical signal from the optical network unit. The method includes determining whether the signal indication includes the loss-of-signal indication. When the signal indication includes the loss-of-signal indication, the method includes instructing the optical transceiver to cease signal transmission from the optical transceiver to the optical network unit. Moreover, when the signal indication includes the signal-received indication, the method includes instructing the optical transceiver to transmit a downstream optical signal from the optical transceiver to the optical network unit.

An optical network communication system utilizes a passive optical network (PON) and includes an optical line terminal (OLT) having a downstream transmitter and an upstream receiver, and an optical network unit (ONU) having a downstream receiver and an upstream transmitter. The downstream transmitter is configured to provide a coherent downlink transmission, and the downstream receiver is configured to obtain one or more downstream parameters from the coherent downlink transmission. The system further includes a long fiber configured to carry the coherent downlink transmission between the OLT and the ONU. The ONU is configured to communicate to the OLT a first upstream ranging request message, the OLT is configured to communicate to the ONU a first downstream acknowledgement in response to the upstream first ranging request message, and the ONU is configured to communicate to the OLT a second upstream ranging request message based on the first downstream acknowledgement.

A circuit board of the optical module comprises: a first electrical interface is configured to connect an electrical interface of a board or a second electrical interface of another optical module, and a second electrical interface is configured to connect a first electrical interface of another optical module; a first optical port is configured to connect an optical transmission device or a second optical port of another optical module, and a second optical port is configured to connect an optical receiving device or a first optical port of another optical module; and a optical transceiver assembly multiplexes downstream light and demultiplexes upstream light. The optical module provided in solutions of the present invention can be flexibly combined with another optical module, enabling flexible and gradual upgrade of an optical module bandwidth according to a user requirement by using various combination manners.

Embodiments relate to providing simultaneous digital and analog services in optical fiber-based distributed radio frequency (RF) antenna systems (DASs), and related components and methods. A multiplex switch unit associated with a head-end unit of a DAS can be configured to receive a plurality of analog and digital downlink signals from one or more sources, such as a service matrix unit, and to assign each downlink signal to be transmitted to one or more remote units of the DAS. In one example, when two or more downlink signals are assigned to be transmitted to the same remote unit, a wave division multiplexer/demultiplexer associated with the multiplex switch unit can be configured to wave division multiplex the component downlink signals into a combined downlink signal for remote side transmission and to demultiplex received combined uplink signals into their component uplink signals for head-end side transmission.

This application discloses a bandwidth allocation method, an optical line terminal (OLT), an optical network unit (ONU), and a system, where the method includes receiving a bandwidth request from each ONU, where the ONU includes an ONU1, generating a bandwidth map (BWMap) message according to bandwidth requested by the ONU and bandwidth configured by the ONU, where the BWMap message includes a first allocation identifier (Alloc-ID1), a first time corresponding to the Alloc-ID1, a second allocation identifier (Alloc-1D2), and a second time corresponding to the Alloc-ID2, and both the Alloc-ID1 and the Alloc-ID2 are allocated to the ONU1 for use, and sending the BWMap message to each ONU. Therefore, a problem that a transmission delay does not satisfy a requirement when a passive optical network (PON) system is applied to mobile backhaul is resolved, a data transmission rate and data transmission efficiency are improved, and user satisfaction is improved.