Abstract: The disclosure provides a method and apparatus for adjusting wavelength for an Optical Line Terminal/Optical Network Unit (OLT/ONU). The method for adjusting wavelength for an OLT includes that: a source OLT sends an adjustment notification message to a target OLT, wherein the adjustment notification message is used for indicating that an ONU is to be adjusted into a Time-Wavelength Division Multiplexing Channel (TWDM CH) of the target OLT; and the source OLT receives an adjustment acknowledgement message provided by the target OLT, wherein the adjustment acknowledgement message is used for indicating that an adjustment process of the ONU has been completed. By means of the technical solution provided in the disclosure, an ONU of a source OLT can still work normally after being switched to a channel of a target OLT, thereby achieving the effect that the continuity of a service between the OLT and the ONU may be maintained.

Abstract: The present disclosure discloses a method and device for channel switching, an Optical Network Unit (ONU) and a system for Time Wavelength Division Multiplexing (TWDM). The method for channel switching includes that: an ONU acquires channel information of a first TWDM channel, wherein the channel information of the first TWDM channel is used for indicating an uplink wavelength and/or downlink wavelength of the first TWDM channel; and the ONU tunes the uplink wavelength and/or downlink wavelength of the ONU into the uplink wavelength and/or downlink wavelength of the first TWDM channel according to the channel information of the first TWDM channel. By means of the present disclosure, the problem of high cost caused by specially building a standby channel for each TWDM channel in a system for TWDM Passive Optical Network (PON) to provide service protection is solved, and the cost of deploying the TWDM PON system is reduced.

Abstract: Disclosed are a method and device for transmitting optical signals. The method comprises: if there is Raman crosstalk between a first optical network system and a coexistence system, an upstream wavelength band of the first optical network system is set outside a range with an upstream wavelength band of the coexistence system being a center and with an impact intensity of the Raman crosstalk being a radius, and a downstream wavelength band of the first optical network system is set outside a range with the downstream wavelength band of the coexistence system being a center and with the impact intensity of the Raman crosstalk being a radius; and optical signals are transmitted by using the upstream wavelength band of the first optical network system and the downstream wavelength band of the first optical network system. The disclosure can avoid interference and improve signal quality.

Abstract: A multi-wavelength passive optical network (MW-PON) includes an optical distribution network (ODN), a plurality of optical line terminations (OLTs) and an optical network unit (ONU). The ODN includes a trunk fiber, one or more branching elements, and a plurality of distribution fibers. Each OLT is associated with an individual bi-directional wavelength channel using a corresponding single downstream wavelength and a corresponding single upstream wavelength, and supporting a specific downstream line rate and one or more distinct upstream line rates. The ONU is communicatively coupled to a respective distribution fiber, being tunable over a specific range of downstream wavelengths and a specific range of upstream wavelengths, and supporting a specific downstream line rate and a specific upstream line rate.

Abstract: Systems, methods and apparatus for operating an optical network terminal (ONT) in a passive optical network include maintaining an operational state in the passive optical network, estimating an upstream channel, adjusting equalization delay and physical layer frame offset values and switching from a backup mode to a primary mode of operation upon detecting a failure condition.

Abstract: A method for upstream bandwidth allocation in a passive optical network is provided by the disclosure. The method includes the following steps: an Optical Line Terminal (OLT) allocates an upstream bandwidth for an Optical Network Unit (ONU) through an upstream bandwidth mapping (US BWmap) domain, wherein the total length B of payloads transmitted by consecutive Transmission Containers (T-CONTs) allocated for the ONU is: the product of the positive integer n and the data byte length L contained in a code word when the ONU uses Forward Error Correction (FEC) encoding, minus the byte length R of the contents protected by FEC, except the payloads, in an upstream burst slot transmitted by the ONU, i.e. B=L×n?R bytes (401); and the ONU encapsulates the upstream data according to the size of the T-CONT total bandwidth allocated by the OLT and transmits it to the OLT (402). A system for upstream bandwidth allocation in a passive optical network is also provided by the disclosure.

Abstract: The present invention discloses a method for transmitting data and a gigabit-capable passive optical network system, which method comprises: a transmitter carrying indication information in an uplink or a downlink frame transmitted to a receiver for enabling the receiver to discard information which does not need to be processed by the receiver in the uplink or downlink frame according to the indication information. The data type transmitted by GPON systems is expanded and the idle bandwidth is effectively handled by the present invention.

Abstract: Disclosed are a method and device for transmitting optical signals. The method comprises: if there is Raman crosstalk between a first optical network system and a coexistence system, an upstream wavelength band of the first optical network system is set outside a range with an upstream wavelength band of the coexistence system being a center and with an impact intensity of the Raman crosstalk being a radius, and a downstream wavelength band of the first optical network system is set outside a range with the downstream wavelength band of the coexistence system being a center and with the impact intensity of the Raman crosstalk being a radius; and optical signals are transmitted by using the upstream wavelength band of the first optical network system and the downstream wavelength band of the first optical network system. The disclosure can avoid interference and improve signal quality.

Abstract: The disclosure provides an optical network system, an Optical Line Terminal (OLT), an Optical Network Unit (ONU) and an Optical Distribution Network (ODN) apparatus. The system includes: an OLT configured to modulate and encode at least one line of time-division-multiplexed downlink signals, synthesize the downlink signals encoded into one line and then output it, receive uplink signals, and decode the uplink signals received and then output them; an ODN configured to separate the downlink signals received into multiple lines and then output them, synthesize the uplink signals received into one line, and then output it to the OLT; and ONUs configured to receive the downlink signals output from the ODN, decode the downlink signals received and output them, encode one line of time-division-multiplexed uplink signals, and output the uplink signals encoded to the ODN. Decoding of the downlink signals and encoding of the uplink signals can further be implemented by the ODN.

Abstract: A power saving method in a passive optical network, including: when receiving an upstream burst timeslot allocated by the Optical Line Terminal (OLT) after a power supply of the Optical Network Unit (ONU) is turned off, the ONU dividing the upstream burst timeslot into one or more upstream burst timeslots; and the ONU turning on own laser in the upstream burst timeslot belonging to the ONU, and after sending one or more emergent Physical Layer Operations, Administration and Maintenance (PLOAM) messages to OLT in each upstream burst timeslot, promptly turning off the own laser. A power saving system in a passive optical network and an optical network unit is provided. The invention can decrease the power supply volume of an electric supply installation in a power-off ONU and reduce the cost of the electric supply installation.

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: A wavelength division multiplexer is provided by the present invention, which implements the wavelength division multiplexing and de-multiplexing of the optical signals in the basic and upgrade bands by reasonably arranging the filters and selecting the spectral properties of the filters, so that the existing time division multiplexing passive optical network (TDM-PON) can transmit the next generation passive optical network (NG-PON) simultaneously and the existing TDM-PON can be smoothly upgraded to the NG-PON, meanwhile, it provides the deployed TDM-PON with the subsequent network compatibility. The wavelength division multiplexer provided in the present invention can meet the high isolation requirement of the optical signals in working band with low cost, and takes both the isolation requirement and the optical network insertion loss requirement into account, thus it has high reliability, is easy to use and for system upgrade.

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 disclosure provides an optical network system, an Optical Line Terminal (OLT), an Optical Network Unit (ONU) and an Optical Distribution Network (ODN) apparatus. The system includes: an OLT configured to modulate and encode at least one line of time-division-multiplexed downlink signals, synthesize the downlink signals encoded into one line and then output it, receive uplink signals, and decode the uplink signals received and then output them; an ODN configured to separate the downlink signals received into multiple lines and then output them, synthesize the uplink signals received into one line, and then output it to the OLT; and ONUs configured to receive the downlink signals output from the ODN, decode the downlink signals received and output them, encode one line of time-division-multiplexed uplink signals, and output the uplink signals encoded to the ODN. Decoding of the downlink signals and encoding of the uplink signals can further be implemented by the ODN.

Abstract: A method for upstream bandwidth allocation in a passive optical network is provided by the disclosure. The method includes the following steps: an Optical Line Terminal (OLT) allocates an upstream bandwidth for an Optical Network Unit (ONU) through an upstream bandwidth mapping (US BWmap) domain, wherein the total length B of payloads transmitted by consecutive Transmission Containers (T-CONTs) allocated for the ONU is: the product of the positive integer n and the data byte length L contained in a code word when the ONU uses Forward Error Correction (FEC) encoding, minus the byte length R of the contents protected by FEC, except the payloads, in an upstream burst slot transmitted by the ONU, i.e. B=L×n?R bytes (401); and the ONU encapsulates the upstream data according to the size of the T-CONT total bandwidth allocated by the OLT and transmits it to the OLT (402). A system for upstream bandwidth allocation in a passive optical network is also provided by the disclosure.

Abstract: A power saving method in a passive optical network, including: when receiving an upstream burst timeslot allocated by the Optical Line Terminal (OLT) after a power supply of the Optical Network Unit (ONU) is turned off, the ONU dividing the upstream burst timeslot into one or more upstream burst timeslots; and the ONU turning on own laser in the upstream burst timeslot belonging to the ONU, and after sending one or more emergent Physical Layer Operations, Administration and Maintenance (PLOAM) messages to OLT in each upstream burst timeslot, promptly turning off the own laser. A power saving system in a passive optical network and an optical network unit is provided. The invention can decrease the power supply volume of an electric supply installation in a power-off ONU and reduce the cost of the electric supply installation.

Abstract: The present invention discloses a method for transmitting data and a gigabit-capable passive optical network system, which method comprises: a transmitter carrying indication information in an uplink or a downlink frame transmitted to a receiver for enabling the receiver to discard information which does not need to be processed by the receiver in the uplink or downlink frame according to the indication information. The data type transmitted by GPON systems is expanded and the idle bandwidth is effectively handled by the present invention.

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: 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.