摘要:
Systems and methods for authenticating key rotation communications. Key rotation communications can include a key counter known to both a headend device and a station. Comparison between a local key counter and the key counter included in the key rotation communication can be used to authenticate the key rotation communication.
摘要:
A method of operating in a network in which a plurality of stations communicate over a shared medium. The method comprises transmitting a group of bits from a transmitting station to a receiving station, wherein the group of bits comprises information bits and error checking bits, and communicating additional bits from the transmitting station to the receiving station without transmitting the additional bits. Communicating the additional bits comprises, at the transmitting station, deriving the error checking bits from the additional bits using an error checking process; and at the receiving station, using the same or a related error checking process to process candidate bits known to the receiving station, and comparing the output of the error checking process to the error checking bits received from the transmitting station to determine if the candidate bits correspond to the additional bits.
摘要:
A scheme for configuring an FEC encoder (including an associated interleaver) for changing data channel characteristics. Channel information specifying a modulation mode and carriers capable of supporting the modulation mode for the data channel is received by a transmitting network node for use in a data transmission to a receiving network node. The received channel information is based on a prior data transmission to the receiving network node over the data channel. Configuration values are computed from the received channel information and an amount of data to be transmitted in a data transmission. The FEC encoder is configured to operate on the data transmission data amount according to the configuration information.
摘要:
A partial ARQ protocol for multicast and broadcast transmissions in network devices operating in a shared medium access network. To support the partial ARQ, a media access control (MAC) protocol uses robustly transmitted frame delimiters and a MAC management frame structure. In a multicast or broadcast frame with partial ARQ, a destination address field is set to that of a selected proxy device's address, and the address of the intended recipients (of group address of the intended recipients) is placed in an entry in the MAC management frame structure. The frame also contains a multicast flag set to indicate that the transmission is intended for more than one device and a value in the frame delimiters to indicate that a response is requested. Upon receipt of such a frame, the proxy device specified by the destination address field provides an appropriate response type on behalf of the group. The non-proxy recipients, detecting the multicast flag setting, know to ignore the DA in the destination address field and instead look to the MAC management entry for actual destination addresses.
摘要:
A scheme for identifying usable carriers for a particular modulation type and selecting, if possible, a modulation type for modulation of OFDM symbol block associated with data packets in a standard transmission mode based on data channel conditions. Channel estimation for an OFDM symbol block received by a receiving network node over a data channel during a packet transmission by a transmitting network node generates information indicative of noise events on symbols and carriers in the OFDM block, the generated information being related to modulation types available for the standard transmission mode, and determines from the generated information if at least one of the modulation types available for the standard transmission mode may be used for a next data transmission over the data channel by the transmitting network node using the standard transmission mode. One of the modulation types is selected if it is determined that at least one of the modulation types may be used. A channel map identifying good carriers for the selected modulation type is produced and stored in memory. If it is determined that one of the modulation modes for the standard transmission mode may not be selected, then a robust transmission mode is chosen instead. The robust transmission mode transmits more reliably (albeit at a lower data rate) than the standard transmission mode. The channel map associated with the standard transmission mode,if produced, or the selection of the robust transmission mode is conveyed to the transmitting network node.
摘要:
An interleaving/de-interleaving scheme for providing redundancy with both time and frequency diversity to data in OFDM symbols in a data transmission system. On the transmit side, encoded data to be modulated onto carriers in OFDM symbols is interleaved by storing the encoded data in an interleaver memory and reading multiple copies of the encoded data from the interleaver memory so that the encoded data copies are spread in time on non-consecutive symbols and in frequency on non-adjacent carriers. On the receive side, the multiple copies of the OFDM data are received, and phase noise computations are used to combine the multiple copies (in either metric or phase angle form) into one. From the combined copies a single metric value to be used in decoding the OFDM data is produced.
摘要:
A windowing mechanism for processing an OFDM symbol is presented. The windowing mechanism applies an apodizing window function having the property Wj+W(FFTSize/2 +j)=constant, where FFTSize is the size of the FFT sample, to a received OFDM symbol sample and a time-offset version of the OFDM symbol sample to produce sets of windowed values. The time-offset sample is offset from the original symbol by one half the symbol period. The time-offset windowed sample is shifted into realignment with the windowed original symbol. Corresponding ones of the windowed values are summed together to restore the windowed symbol to its original form.
摘要:
Systems and methods for authorizing a customer premise equipment (CPE) device to join a network through a network termination unit (NTU). The CPE device can send an encrypted connection request, and an authorization server can decrypt the connection request and provide a network membership key (NMK) associated with the CPE device to the NTU. The authorization server can encrypt the NMK associated with the CPE device using a device access key (DAK) associated with the NTU.
摘要:
Network devices of a particular device class can implement a distributed bandwidth control (DBC) protocol to utilize resources of a communication network in accordance with a threshold amount of resources allocated for DBC device communication. A DBC device of a plurality of DBC devices can determine a transmission cost associated with a pending DBC transmission. The pending DBC transmission is initiated. A delay time period associated with the initiated pending DBC transmission can be calculated based, at least in part, on the transmission cost associated with the initiated DBC pending transmission and a threshold transmission cost associated with DBC device communications. Subsequent transmissions of the DBC device and all other DBC devices in the communication network can be delayed by at least the delay time period associated with the initiated pending DBC transmission of the DBC device.
摘要:
Associating service agents in communication over a network to one or more respective clients coupled to the network at respective ports of the network is described. At a first service agent, a first signal is received from a first client coupled to the network at a first port. The first signal propagates over a first signal propagation path between the first service agent and the first port. An association between the first service agent and the first client is established based at least in part on a difference between: the first signal propagation path between the first service agent and the first port, and a second signal propagation path between the first service agent and a second port or between a second service agent and the first port.