Abstract: Disclosed herein are mechanisms to support the management of multicast keys for a multicast group comprising one or more optical line terminals (OLTs), one or more fiber to coax units (FCUs), and a plurality of coax network units (CNUs). The disclosed embodiments may support the management of multicast keys over optical and coaxial networks. In some embodiments, an FCU may facilitate communication of operations administration and maintenance (OAM) messages containing multicast keys from one or more OLTs to one or more CNUs (typically a plurality of CNUs). Some embodiments may employ one multicast key over both the optical network and coaxial network. Other embodiments may employ an optical domain multicast key over the optical network and an electrical domain multicast key over the coaxial network. Embodiments may comprise adding a first CNU to a multicast group as well as adding subsequent CNUs to the multicast group.

Abstract: Embodiments of the present disclosure provide an FEC coding and decoding method and device, and a system. A transmit end determines a forward error correction FEC coding type according to a length of to-be-coded data in burst data, and performs coding according to the determined FEC coding type. A receive end determines a forward error correction FEC decoding type according to a length of to-be-decoded data in burst data, and performs decoding according to the determined FEC decoding type. The FEC coding and decoding method provided in the embodiments of the present disclosure improves utilization of a communication resource is improved, and saves a communication resource.

Abstract: Embodiments of the present invention provide a forward error correction codeword synchronization method, device, and system. The method is: sending, by a central office device, synchronization information of an FEC codeword to a terminal device by using a management channel, where the information includes information about an agreed location of an FEC codeword, and the information about the agreed location of the first FEC codeword indicates a location that is of the first FEC codeword and is corresponding to data at an agreed location of an agreed time-frequency resource block; and receiving, by the terminal device, the synchronization information that is of the FEC codeword and is sent by the central office device, and adjusting a status parameter of an encoder or a decoder according to the information, so as to complete codeword synchronization. The embodiments of the present invention are used for FEC codeword synchronization.

Abstract: A method performed by a FCU comprising receiving a MPCP request message from a CNU via an electrical network, wherein the MPCP request message comprises a first timestamp, adjusting the first timestamp in the MPCP request message by an electrical network delay, and forwarding the MPCP request message with the adjusted timestamp to an OLT via an optical network. Also disclosed is a method performed by an OLT comprising receiving a MPCP message from a CNU via a FCU and an optical network, obtaining an arrival time of the MPCP message, adjusting a timestamp in the MPCP message by subtracting an electrical network delay from the timestamp, and computing a RTT delay based on the timestamp and the arrival time.

Abstract: Embodiments of the present invention provide a logical link identifier (LLID) registration method, device, and system. The method includes: receiving, by a coax media converter (CMC), a first registration request sent by at least one coaxial network unit (CNU) that is connected to the CMC, where the first registration request carries the media access control (MAC) address of the CNU; and sending, by the CMC, in a first data window allocated to the CMC by an optical line terminal (OLT), a second registration request to the OLT, where the second registration request carries a first level LLID identifier allocated to the CMC by the OLT and the MAC address of the CNU, and the first data window is used for data exchange between the CMC and the OLT.

Abstract: An apparatus for communication. A headend supports a plurality of customer premises equipment (CPEs) in a cable service network. An NCP carrier selector selects at least one orthogonal frequency division multiplex (OFDM) subcarrier taken from a radio frequency (RF) spectrum available for broadcasting signals over the cable service network using a plurality of profiles, wherein each selected OFDM subcarrier comprises a corresponding bit loading for each supported profile that meets or exceeds a minimum number of bits used for delivering next codeword pointer (NCP) messages that is acceptable for each of a plurality of profiles used in the plurality of CPEs for receiving signals over the cable service network. A profile generator generates an NCP profile identifying one or more selected OFDM subcarriers, wherein the NCP profile indicates which OFDM subcarriers within the RF spectrum are usable to carry NCP messages, and an associated bit loading for each selected subcarrier.

Abstract: Disclosed herein are mechanisms to support the management of multicast keys for a multicast group comprising one or more optical line terminals (OLTs), one or more fiber to coax units (FCUs), and a plurality of coax network units (CNUs). The disclosed embodiments may support the management of multicast keys over optical and coaxial networks. In some embodiments, an FCU may facilitate communication of operations administration and maintenance (OAM) messages containing multicast keys from one or more OLTs to one or more CNUs (typically a plurality of CNUs). Some embodiments may employ one multicast key over both the optical network and coaxial network. Other embodiments may employ an optical domain multicast key over the optical network and an electrical domain multicast key over the coaxial network. Embodiments may comprise adding a first CNU to a multicast group as well as adding subsequent CNUs to the multicast group.

Abstract: Embodiments of the present invention provide a method, an apparatus, and a system for multiple access. The method includes: receiving, by a network device, a data packet, where the data packet includes identifier information about a terminal; querying, according to the identifier information about the terminal, a correspondence table between identifier information about a terminal and a broadcast channel, and determining a broadcast channel corresponding to the identifier information about the terminal, where the determined broadcast channel is a broadcast channel among a plurality of preset broadcast channels, and the terminal is any terminal in a terminal group corresponding to the determined broadcast channel; and sending, according to the identifier information about the terminal, through the determined broadcast channel, the data packet to the terminal.

Abstract: Embodiments of the present invention provide a logical link identifier (LLID) registration method, device, and system. The method includes: receiving, by a coax media converter (CMC), a first registration request sent by at least one coaxial network unit (CNU) that is connected to the CMC, where the first registration request carries the media access control (MAC) address of the CNU; and sending, by the CMC, in a first data window allocated to the CMC by an optical line terminal (OLT), a second registration request to the OLT, where the second registration request carries a first level LLID identifier allocated to the CMC by the OLT and the MAC address of the CNU, and the first data window is used for data exchange between the CMC and the OLT.