Abstract: 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.

Abstract: Systems and methods for connecting new stations to a secure network. New stations can send connection requests to a headend device. The headend device can retrieve a device access key associated with the new station and can provide a network membership key to the new station based upon authentication of the new station using the device access key.

Abstract: Methods, systems, and apparatuses are described for communicating among stations in a network. A station in the network can determine costs between that station and a headend through a number of other stations and selecting a low cost path from among the possible paths. Cost data from the determination can be transmitted from the station to other stations in the network for use in selecting low cost paths at those stations.

Abstract: 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.

Abstract: Communicating over a network of communication stations includes monitoring for reception of an electromagnetic wave that has a power above a threshold and a frequency in a predetermined frequency interval, and selecting carrier frequencies for modulating information onto signals transmitted over the network. The carrier frequencies are selected based at least in part on whether an electromagnetic wave having a power above the threshold and a frequency in the frequency interval has been received in a predetermined time interval, and based at least in part on a demand by one or more stations in the network for capacity for communicating over the network.

Abstract: A method and system for estimating a time shift required for symbol synchronization in a block oriented digital communication systems such as an orthogonal frequency division multiplexing (OFDM) or a discrete multi-tone (DMT) data transmission system. The method uses an N/d inverse discrete Fourier transform (IDFT), where N is a sample number and d is a decimation factor, or alternatively an N/(2d) inverse fast Fourier transform (IFFT) for a real received signal or an N/d IDFT for a complex received signal.

Abstract: An access contention scheme having both multi-level priorities and a contention-free access indicator for use by a station in a network of stations. When a contention control indicator is detected for a contention period, a station having a frame to transmit determines from the contention control indicator if it is permitted to contend for access to the transmission medium during the contention period. The station determines if the contention control indicator indicates a contention-free access and, if the contention control information indicates a contention-free access, the station determines if a channel access priority level associated with the frame to be transmitted is higher than a channel access priority level associated with a last transmitted frame.

Abstract: A method and apparatus for detecting a channel jammed by narrowband jamming interference in a block oriented digital transmission system such as an orthogonal frequency division multiplexing (OFDM) or discrete multi-tone (DMT) system. A spectrum of a received data bearing signal is examined to identify areas of the spectrum that are likely corrupted by a narrowband jamming interference. The method identifies jammed channels by applying a boxcar filter, in order to identify narrow peaks in the spectrum that are substantially larger in magnitude than adjacent channels. Channels identified as jammed or affected by a jamming signal, are listed in a jam mask used for screening out corrupted channels during data transmission.

Abstract: A rate-adaptive mechanism for optimizing transmitter/receiver connections on a carrier-by-carrier basis for maximum date rate based on channel attributes for that connection and direction. Channel information is produced by a channel adaptation process based on channel characteristics and is stored in both transmitter and receiver as a channel map with an associated a channel map index for channel map look-up. The channel map index for a channel map used to modulate a payload of a frame is conveyed by transmitter to receiver in the frame so that the receiver is able to select the correct channel map for demodulation.

Abstract: 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.

Abstract: An analog signal gain control circuit(ASGC) for a digital radio HomePlug orthogonal frequency division multiplexing (OFDM) receiver includes a digital variable gain amplifier (DVGA) to control the gain of a received signal to achieve a desired signal amplitude to match a dynamic range of an analog-to-digital converter (ADC), an inverse scaling stage controlled to inverse-scale the signal output by the ADC, and a two-stage fast attack and slow decay filter that outputs control signals to the DVGA and to the inverse scaling stage. The fast attack and slow decay filter rapidly responds to an increase in signal amplitude and slowly decays the amplitude of the control signal in response to a decrease in input signal amplitude.

Abstract: A transmit process that limits the time during which a reduced network bandwidth exists between two powerline nodes because a receiving node fails to respond to frame transmission attempts by a transmitting node is described. The transmit process restricts the number of retries that occur in a lower date rate transmission mode and, for a predetermined time period to follow, drops all subsequent frames destined for the non-responding node.

Abstract: A method and system for estimating a time shift required for symbol synchronization in a block oriented digital communication systems such as an orthogonal frequency division multiplexing (OFDM) or a discrete multi-tone (DMT) data transmission system. The method uses an N/d inverse discrete Fourier transform (IDFT), where N is a sample number and d is a decimation factor, or alternatively an N/(2d) inverse fast Fourier transform (IFFT) for a real received signal or an N/d IDFT for a complex received signal.

Abstract: A frame forwarding scheme for network stations operating in a shared medium data transmissions network. The frame forwarding scheme uses payload encapsulating delimiters and control information in the payload to enable a frame originating from a first station and intended for a second station to be forwarded to the second station by an intermediate station. The first station selects a station as an intermediate station for purposes of frame forwarding based on the data transmission quality or reliability to be achieved using that station as an intermediate station.

Abstract: A scheme for bounding latency of transmissions for QoS in network stations operating in shared medium access network. The length of segment burst transmissions are limited by allowing the segment burst transmission of a given priority to be interrupted by higher priority traffic. Restrictions are placed on frame length for transmissions of all priority levels or, alternatively, at all but the highest of the priority levels.

Abstract: A CSMA Media Access Control (MAC) scheme for supporting both centralized and distributed shared medium access control in a CSMA network. A master device exchanges connection control messages with a slave during using contention-oriented access to establish a connection and a session of periodic contention-free intervals. Once the session is established, the contention-free intervals alternate with contention-oriented intervals according to the timing parameters specified by the connection control messages.

Abstract: Coupling circuitry implemented with passive components is added to a conventional power supply to enable communications access to a power-line network by a device designed for power-line communications (“PLC device”), in order to achieve certain benefits including minimizing costs.

Abstract: A system and method is described for reliably transferring a node in a communications network from one Logical Network to another Logical Network. The system and method is reliable and robust with respect to potentially varying implementations of host devices in the communications network, and is compatible with other network management operations as specified in HomePlug Specifications.

Abstract: A robust Media Access Control (MAC) scheme for network stations operating in an OFDM transmissions network. The MAC scheme uses robustly transmitted frame control information to ensure network synchronization (for media access) and convey channel access prioritization for QoS. Frame control information can occur in a frame before and after the frame's payload, or in a response.

Abstract: A source-aware bridging scheme for supporting bridging between a noisy (“unreliable”) network and another, reliable network. Each device connected to the medium of the unreliable network includes a source-aware MAC that maintains a Bridge Proxy Destination Address list (BPDAlist) of all destination addresses that reside on the other network and are reached by a bridge. The BPDAlist information can be learned by the source-aware MAC during a frame receive and/or received during a channel estimation cycle. The list associates destination addresses with the address of the particular bridge through which the destination addresses are accessed. The bridge serves as a proxy with respect to those destination addresses and thus maintains its own list of the destination addresses for which it serves as proxy, or, IAPlist. The IAPlist can be learned, or passed down to the source-aware MAC from a learning bridge process or from the local host to which the device is coupled.