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.

Embodiments herein relate to a method in a network unit for monitoring a fiber line between a radio base station and a radio head in a Fiber to the Radio Head communications network. The Fiber to the Radio Head communications network comprises a ring architecture or a tree architecture of fiber, with Subcarrier Multiplexing, SCM, downstream transmissions and Wavelength Division Multiplexing, WDM, upstream transmissions. The monitoring comprises that the network unit detects an indication of a fault along the fiber line based on monitoring power. The network unit initiates, in response to detect the indication, an Optical?Domain Reflectometry, O?DR, measurement over the fiber line. Additionally, the network unit analyses a trace from the O?DR measurement for localizing the fault or for deciding that the indicated fault is not a fault along the fiber line.

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.

According to an aspect of an embodiment, a method may include assigning an activation window by an optical line terminal during a portion of an upstream transmitting window in a passive optical network (PON). The method may include performing a first modification to a first upstream transmission. The method may include performing a second modification to a second upstream transmission. The method may include receiving the first upstream transmission from a first optical network unit (ONU) during the activation window, the first ONU synchronized in the PON. The method may include receiving a second upstream transmission from a second ONU during the activation window, the second ONU requesting activation in the PON.

An optical line terminal (OLT) comprises a target OLT channel termination (CT), and a source OLT CT in communication with the target OLT CT, wherein the source OLT CT is configured to exchange tuning messages with the target OLT CT to initiate upstream wavelength tuning of an optical network unit (ONU), wherein the source OLT CT is configured to transmit a tuning request to the ONU after the tuning messages have been exchanged and to receive a tuning acknowledgement message from the ONU indicating that the tuning request will be executed, wherein the source OLT CT is configured to transmit a broadcast notification message to all OLT CTs within the OLT, except for the source OLT CT, after receipt of the tuning acknowledge message from the ONU, and wherein the broadcast notification message includes a tuning time of the ONU.

Systems and methods for detecting laser transmission bursts in a CATV network.

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The invention provides a method and apparatus for downstream flow control in an (x)GPON system. First, ONU sends a DS_FlowControl_Request message to OLT, wherein the DS_FlowControl_Request message includes information of transmission inhibiting period and is used for requesting OLT to inhibit downstream transmission for a transmission inhibiting period corresponding to the information of transmission inhibiting period. After receiving the DS_FlowControl_Request message from ONU, OLT inhibits the downstream transmission for the transmission inhibiting period corresponding to the information of transmission inhibiting period based on the information of transmission inhibiting period included in the DS_FlowControl_Request message. After inhibiting the downstream transmission for the transmission inhibiting period corresponding to the information of transmission inhibiting period, OLT resumes the downstream transmission to ONU.

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 line terminal (OLT) comprises a target OLT channel termination (CT), and a source OLT CT in communication with the target OLT CT, wherein the source OLT CT is configured to exchange tuning messages with the target OLT CT to initiate upstream wavelength tuning of an optical network unit (ONU), wherein the source OLT CT is configured to transmit a tuning request to the ONU after the tuning messages have been exchanged and to receive a tuning acknowledgement message from the ONU indicating that the tuning request will be executed, wherein the source OLT CT is configured to transmit a broadcast notification message to all OLT CTs within the OLT, except for the source OLT CT, after receipt of the tuning acknowledge message from the ONU, and wherein the broadcast notification message includes a tuning time of the ONU.