A device includes a transmitter coupled to a node, where the node is to couple to a wired link. The transmitter has a plurality of modes of operation including a calibration mode in which a range of communication data rates over the wired link is determined in accordance with a voltage margin corresponding to the wired link at a predetermined error rate. The range of communication data rates includes a maximum data rate, which can be a non-integer multiple of an initial data rate.

An example system includes a hub transceiver and a plurality of edge transceivers. The hub transceiver is operable to determine a plurality of optical subcarriers available for assignment by the hub transceiver to the plurality of the edge transceivers for use in communicating over an optical communications network, and assign, to each of the edge transceivers, a respective subset of the optical subcarriers. Each of the subsets of the optical subcarriers includes a respective data optical subcarrier for transmitting data over the optical communications network. At least one of the subsets of the optical subcarriers includes one or more respective idle optical subcarriers. The hub t transceiver is also operable to transmit to each of the edge transceivers, an indication of the respective subset of the optical subcarriers assigned to the edge transceiver.

A driver of an Ethernet controller may determine, based on an interrupt received from a PHY circuit coupled to the Ethernet controller, that a connection between the PHY circuit and a remote device was established using auto-negotiation over a physical communication medium. The driver may determine a speed of the connection. The driver may, based on a determination that the speed of the connection is not a first predetermined speed, enable auto-negotiation between the PHY circuit and the Ethernet controller to establish a link at a second speed that is different than the first predetermined speed.

An example system includes an optical gateway, plurality of hub transceivers, and a plurality of edge transceivers. The optical gateway is operable to receive a plurality of signals from an optical communications network at a plurality of ports of the optical gateway, where each port of the optical gateway comprises one or more respective photodiodes. Further, the optical gateway is operable to determine, for each port, a respective link of the optical communications network communicatively coupling the port with at least one hub transceiver of the plurality of hub transceivers or with at least one edge transceiver of the plurality of edge transceivers, and an identity of the at least one hub transceiver or the at least one edge transceiver.

An example system includes a hub transceiver, a plurality of edge transceivers, and a control module. The control module is operable to receive, from one or more of the edge transceivers or the hub transceiver, telemetry data regarding at least one of a transmission or a receipt of data over the optical communications network, and determine, based on the telemetry data, performance characteristics regarding the optical communications network. Further, the control module is operable to transmit, based on the performance characteristics, a command to one or more of the edge transceivers or the hub transceiver to modify an operation with respect to the optical communications network.

An OFDM system uses a normal mode which has a symbol length T, a guard time TG and a set of N sub-carriers, which are orthogonal over the time T, and one or more fallback modes which have symbol lengths KT and guard times KTG where K is an integer greater than unity. The same set of N sub-carriers is used for the fallback modes as for the normal mode. Since the same set of sub-carriers is used, the overall bandwidth is substantially constant, so alias filtering does not need to be adaptive. The Fourier transform operations are the same as for the normal mode. Thus fallback modes are provided with little hardware cost. In the fallback modes the increased guard time provides better delay spread tolerance and the increased symbol length provides improved signal to noise performance, and thus increased range, at the cost of reduced data rate.

A configurable transceiver includes a first transmitter, an edge rate controller, a second transmitter, a subtractor, a bandwidth controller and a main controller. The first transmitter is configured to generate a first signal for transmission via a transmission link. The second transmitter is configured to generate a replica signal associated with the first signal. The edge rate controller is communicatively coupled to the first and/or second transmitter and is configured to control an edge rate parameter of the first and/or second signal. The subtractor is configured to subtract the replica signal from a signal received via the transmission link. The bandwidth controller is configured to control a bandwidth parameter of a difference signal received from the output of the subtractor. The main controller chooses edge rate and bandwidth control words per desired link rates. It can also automatically find the maximum possible link speed.

A system comprising a hub transceiver coupled to a first network node; and a plurality of edge transceivers, each configured to be communicatively coupled to a respective second network node, and to the hub transceiver, wherein the hub transceiver is operable to transmit a first message to each of the edge transceivers, the first message comprising an indication of available optical subcarriers and availability to use multiple non-contiguous optical subcarriers; receive, a service request identifying a selected subset of the available optical subcarriers including a non-contiguous first optical subcarrier and second optical subcarrier, transmit a second message to indicate either a success or a failure, and receive, via the selected subset, data from the second network node, and wherein at least one of the edge transceivers is operable to, transmit, using the selected subset of available optical subcarriers, data from the second network node to the first network node.

A downlink channel estimation method and apparatus based on a sounding reference signal (SRS), and a communications system. The method includes: a base station receives a SRS sent by UE, the SRS being used for downlink channel estimation and supporting high-dimensional MU-MIMO; performing uplink channel estimation according to the SRS; and acquiring downlink channel information according to uplink channel information obtained in the uplink channel estimation. By means of embodiments of the present disclosure, downlink reference signal overheads and feedback overheads can be remarkably reduced, gain brought by large-scale antennas is obtained, and the system capacity can be further improved.

Embodiments provide solutions to reduce power utilization (either at individual cable modems or in the overall network) in future cable modem networks. Particularly, embodiments seek to reduce power utilization at individual cable modems and in the overall network, by allocating upstream frequency bands and/or transmission modulation schemes among cable modems while accounting for cable loss experienced by individual upstream cable modem transmissions. According to embodiments, frequency spectrum and modulation scheme allocation techniques are provided to optimize power utilization and enable lower upstream transmission power by cable modems while maintaining similar signal strength of received signals or lower signal strength with reduced SNR requirements using lower capacity modulation at the headend.