A passive optical network includes a central office providing subscriber signals; a drop terminal; and a wave division multiplexer. A fiber distribution hub may split or separate out dedicated optical signals from subscriber optical signals between the central office and the drop terminal. The wave division multiplexer separates dedicated optical signals pertaining to a specific dedicated subscriber from other optical signals on the line received at the wave division multiplexer. The wave division multiplexer may be part of a cable or part of an intermediate service terminal.

The present disclosure relates to an optical fiber access system based on passive optical networks. In particular the present disclosure relates to a PON system with increased capacity and a method for increasing the capacity in a PON system. One embodiment relates to an optical line terminal for a passive optical network, comprising at least one transmitter for generating a time division multiplexed (TDM) downstream optical data signal, a first time lens optical signal processor configured to convert the downstream TDM signal to a downstream WDM signal for distribution to a plurality of users, and at least one receiver for receiving and processing an upstream signal from said users.

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.

An optical transmission system of an embodiment connects a plurality of wireless communication systems to each other, and includes a wavelength allocation unit that allocates different wavelengths to optical-terminating devices to which the wireless communication systems next to each other are connected, on the basis of the physical arrangement of each of the plurality of wireless communication system.

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.

Optical fiber-based wireless systems and related components and methods are disclosed. The systems support radio frequency (RF) communications with clients over optical fiber, including Radio-over-Fiber (RoF) communications. The systems may be provided as part of an indoor distributed antenna system (IDAS) to provide wireless communication services to clients inside a building or other facility. The systems incorporate various functions, such as optical network terminal (ONT), splitter, and local powering, in antenna coverage areas.

Embodiments of the present disclosure provide a passive optical network communications method and apparatus, and a system. The method includes: determining a wavelength channel group of an optical network unit (ONU) and a wavelength channel in the wavelength channel group; and sending a first message to the ONU, where the first message carries identification information of the wavelength channel group and identification information of the wavelength channel in the wavelength channel group. In the embodiments of the present disclosure, such a logical channel group as a wavelength channel group is established, and when a channel in a channel group is faulty, a scheduling module of an OLT can rapidly and easily reallocate a service to another member in the channel group, so that channel interaction is avoided. Therefore, bandwidth scheduling efficiency and bandwidth utilization of a PON system are higher.

A method and apparatus for communications in a passive optical network (PON) system are provided. An optical line terminal (OLT) generates a PON downstream Physical Layer (PHY) frame comprising a downstream physical synchronization block (PSBd) that comprises a wavelength identification (ID) of at least one downstream wavelength of the plurality of downstream wavelengths. The OLT sends the PON PHY frame comprising the wavelength ID in the PSBd to ONU for confirming the at least one downstream wavelength.

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.

A CU (Central Unit) executes scheduling for allocating radio resources of RRUs (Remote Radio Units) to radio transmission of downlink data while broadcasting, to DMs (Data Managers) via MFH, downlink data from MBH. Each DM selects, based on an allocation result obtained by scheduling, the downlink data of an RRU (Remote Radio Unit) corresponding to the self DM from the accumulated downlink data from the CU, and transfers the selected downlink data to the corresponding RRU while discarding the downlink data of other RRUs. Based on the allocation result, each RRU performs radio transmission of the downlink data from the DM to a corresponding UE (User Equipment) using the designated radio resource. This makes it possible to efficiently transfer the downlink data from the CU to each RRU via the MFH constructed by a TDM system represented by TDM-PON.