Abstract: The present invention discloses a ranging method for an optical network unit in a passive optical network, which includes: an Optical Line Terminal (OLT) performing ranging for an Optical Network Unit (ONU) in a operation state, updating an Equalization Delay (EqD) of the ONU according to a ranging result, and sending the updated EqD to the ONU; and the ONU implementing an upstream transmission synchronization according to the updated EqD. The present invention further discloses a ranging system for an optical network unit (ONU) in a passive optical network (PON), which includes a ranging device and an equalization delay updating device. In the present invention, the influence on the interruption of services of the ONU for which ranging is performed is reduced, and the time-sensitive services of the ONU for which ranging is performed are protected, thus improving the upstream transmission efficiency of the ONU.

Abstract: A method for managing upstream burst overhead parameters includes: an Optical Line Terminal (OLT) or an Optical Network Unit (ONU) detects transmission quality of a downlink between the OLT and the ONU; the OLT or the ONU determines the upstream burst overhead parameters suitable for the ONU according to the transmission quality; and the ONU starts to use the upstream burst overhead parameters suitable for the ONU after the switching time determined by the ONU itself or indicated by the OLT. The present invention also provides an ONU and an OLT for managing the upstream burst overhead parameters. The present invention can improve the bandwidth utilization rate and decrease the complexity of indicating the upstream burst overhead parameters in PON system, so that the ONU and the OLT are enabled to flexibly and simply select the upstream burst overhead parameters.

Abstract: The present invention provides a transmission method for a physical layer operations, administration and maintenance (PLOAM) message in a passive optical network. The method includes: a transmitter dividing a PLOAM message to generate more than two new PLOAM messages, each of which comprises at least a message identification (Message ID) field (1501); and the transmitter transmitting the new PLOAM messages identified with Message IDs (1502). The invention also provides an assembling method for a PLOAM message in a passive optical network and a transmission device for a PLOAM message in a passive optical network. By using the method of the invention, the invention improves the efficiency of the PLOAM message transmission, avoids bandwidth waste, and simultaneously improves the flexibility and timeliness of the PLOAM message transmission between an OLT and an ONU.

Abstract: The present invention discloses a method for ranging in a passive optical network, and the method includes: obtaining a Round Trip Delay (RTD) between an Optical Line Terminal (OLT) and an Optical Network Unit (ONU); and opening a quiet window used for the ranging for the ONU according to the RTD to perform the ranging on this ONU. The present invention further discloses an apparatus for ranging in a passive optical network, and the apparatus includes: an obtainment module which is configured to: obtain a RTD between an OLT and an ONU; and a ranging module configured to: open a quiet window used for ranging for the ONU to perform ranging on the ONU according to the RTD. The present invention shortens the open time of the quiet window used for the ranging and improves the efficiency of the upstream transmission, and the implementation method is simple and convenient.

Abstract: The disclosure provides a method for quickly updating ranging results of optical network units by an optical line terminal. The method comprises the following steps: an Optical Line Terminal (OLT) distributes an acquired ranging difference to all the Optical Network Units (ONUs); and the current ONU implements quick updating of the ranging result of the current ONU itself according to the acquired ranging difference. The disclosure also provides a system for quickly updating ranging results of ONUs by an OLT, wherein a distributing unit in the OLT is used for distributing an acquired ranging difference to all the ONUs; an updating unit in the ONU is used for implementing quick updating of ranging result of the current ONU itself according to the acquired ranging difference. the method and system of the disclosure can save the quantity of messages, enable quick switching in protection status, thus implementing protection switching efficiently.

Abstract: The present invention discloses a method for instructing enabling/disabling Forward Error Correction (FEC) function. The method comprises: presetting an instruction identifier of an FEC status; transmitting an instruction identifier of an FEC status of an Optical Network Unit (ONU) and the Identity (ID) of the ONU by an Optical Line Terminal (OLT), wherein the instruction identifier of the FEC status of the ONU is corresponding to the ID of the ONU; and enabling or disabling its own FEC function by the ONU according to the received instruction identifier corresponding to its own ID. The present invention also discloses a system for instructing enabling/disabling FEC function, which comprises an OLT and an ONU. The method and system of the present invention can solve the problem that the ONU cannot determine the instruction from the OLT due to an error code.