The present disclosure relates to an optical line terminal, OLT, which is enabled to range optical network units, ONUs, in a point-to-multipoint optical network by detecting interference burst sequences transmitted by one or more joining ONUs during transmission of upstream data traffic from transmitting ONUs. The present disclosure further relates to an optical network unit, ONU, which is enabled to transmit, at a selected transmission time, an interference burst sequence including a sequence of pulses allowing the OLT to identify the ONU as a joining ONU.

A time providing method includes: by a computer, upon receiving data from a device, estimating a generation time of the data using a reception time of the data and a first delay time of the device previously estimated; providing information indicating the generation time to the data; and transmitting the data provided with the information indicating the generation time to a destination of the data.

Using timing delays and values associated with plant information between a CMTS, R-PHY device or a remote MACPHY device and user devices on a network to determine the distance between a head end device, for example a CMTS, R-PHY device or a remote MACPHY device and an end-user device such as cable modem in order to alert to a stolen, outdated, misplaced or otherwise at-risk end-user device.

Systems and methods of the present disclosure provide for dynamic delay equalization of related media signals in a media transport system. Methods include receiving a plurality of related media signals, transporting the related media signals along different media paths, calculating uncorrected propagation delays for the media paths, and delaying each of the related media signals by an amount related to the difference between the longest propagation delay (of the uncorrected propagation delays) and the uncorrected propagation delay of the related media signal/media path. Calculating the uncorrected propagation delays and delaying the related media signals may be performed in response to a change to the propagation delay of at least one of the related media signals/media paths. Additionally or alternatively, calculating the uncorrected propagation delays and delaying the related media signals may be performed while transporting the related media signals.

A method for determining timing information in an optical communication link includes transmitting a falling edge from a transceiver positioned at a near end of the optical communication link and simultaneously starting a first timer at the transceiver positioned at the near end of the link. The transmitted falling edge is received at a transceiver positioned at a far end of the link. A falling edge is transmitted from the transceiver positioned at the far end of the link after a response delay. The transmitted falling edge is received at the transceiver positioned at the near end of the link while the first timer is simultaneously terminated at the transceiver positioned at the near end of the link and the elapsed time is recorded. The total link delay is determined based on the elapsed time.

A method includes, at a first node: transmitting a first synchronization signal at a first time according to a first clock of the first node; back-coupling the first synchronization signal to generate a first self-receive signal; calculating a time-of-arrival of the first self-receive signal according to the first clock; and calculating a time-of-arrival of the second synchronization signal according to the first clock. The method also includes, at the second node: transmitting the second synchronization signal at a second time according to a second clock of the second node; back-coupling the second synchronization signal to generate a second self-receive signal; calculating a time-of-arrival of the second self-receive signal according to the second clock; and calculating a time-of-arrival of the first synchronization signal according to the second clock. The method S100 further includes calculating a time bias and a propagation delay between the pair of nodes based on the time-of-arrivals.

According to an aspect of the disclosure, a mobile communication repeater comprises a receiver configured to receive a plurality of test signals from a plurality of external communication devices and subsequently, receive a plurality of downlink signals from the external communication devices, and a digital signal processor configured to measure a delay time of each of the plurality of test signals, generate a sync time based on the delay times, and delay each of the plurality of downlink signals to correspond with the sync time.

Timestamp circuitry of a network device modifies a packet by embedding a future timestamp in the packet to generate a timestamped packet. The future timestamp corresponds to a transmit time that occurs after the timestamp circuitry embeds the future timestamp in the packet. The timing information is added to the packet and the packet is then transferred to transmitter circuitry of the network device via a communication link, internal to the network device, that operates according to a media independent communication interface. Time gating circuitry of the transmitter circuitry i) holds the timestamped packet from proceeding to a network link coupled to the network device prior to a current time reaching the transmit time, and ii) releases the timestamped packet for transmission via the network link in response to the current time reaching the transmit time.

A derivation method is a derivation method performed by a communication system, including: a transmission step of transmitting a first radio-wave signal according to an optical signal with a first wavelength and a second radio-wave signal according to an optical signal with a second wavelength; a communication start time information acquisition step of acquiring information on a first communication start time and information on a second communication start time; a reception time information acquisition step of acquiring information on a first reception time that is a reception time related to the first radio-wave signal, and information on a second reception time that is a reception time related to the second radio-wave signal; and an optical fiber length derivation step of deriving a length of the optical fiber, based on the first communication start time, the first reception time, the second communication start time, the second reception time, a group velocity or a group delay time of the optical signal with the first wavelength, and a group velocity or a group delay time of the optical signal with the second wavelength.

A vehicular control system includes a first electronic control unit (ECU) and a second ECU disposed at a vehicle. The first and second ECUs are in digital communication with one another via a communication link. The first ECU transmits a first frame to the second ECU, which, responsive to receiving the first frame from the first ECU, transmits a second frame to the first ECU. The first ECU, responsive to receiving the second frame from the second ECU, determines a propagation delay based on an amount of time between when the first ECU transmitted the first frame to the second ECU and when the first ECU received the second frame from the second ECU. The first ECU, responsive to determining the propagation delay, transmits a time synchronization frame to the second ECU that is based at least in part on the determined propagation delay.