摘要:
An optical communications network architecture and associated method which employs time and wavelength-interleaving for homing between nodes/satellites and hubs and for grooming, while employing wavelength-division-multiplexed wavelength circuits between hubs without requiring cross-connects or routers therebetween.
摘要:
An optical communications network architecture and associated method which employs time and wavelength-interleaving for homing between nodes/satellites and hubs and for grooming, while employing wavelength-division-multiplexed wavelength circuits between hubs without requiring cross-connects or routers therebetween.
摘要:
An access node of a communication system comprises a plurality of transmitters adapted for communication with at least one receiver. The access node is operative to simultaneously estimate channel coefficients between multiple ones of the transmitters and the receiver, and to utilize the estimated channel coefficients to control at least one data signal sent by at least one of the multiple transmitters to the receiver. In the process of simultaneously estimating the channel coefficients, the access node transmits a plurality of distinct probing signals, each of which is generated based on a distinct combination of a common probing sequence and a selected one of a plurality of different frequency expansions. The access node may comprise at least a portion of at least one central office of a DSL communication system.
摘要:
A method includes maintaining temporally parallel DSL data communication sessions with DSL modems of a group via a set of lines. The method includes, in response to substantially stopping to receive DSL communications from one of the DSL modems via one of the lines, transmitting a substantially reduced average power to the one of the lines and monitoring the one of the lines to determine whether DSL communications have restarted being received from the one of the DSL modems. The method also includes resuming the maintaining of the temporally parallel DSL communication sessions in response to the monitoring determining that DSL communications have restarted being received from the one of the DSL modems.
摘要:
An access node of a communication system comprises a plurality of transmitters adapted for communication with at least one receiver. The access node is operative to simultaneously estimate channel coefficients between multiple ones of the transmitters and the receiver, and to utilize the estimated channel coefficients to control at least one data signal sent by at least one of the multiple transmitters to the receiver. In the process of simultaneously estimating the channel coefficients, the access node transmits a plurality of distinct probing signals generated based on respective ones of a plurality of different frequency expansions. For example, each of the distinct probing signals may be generated based on a distinct combination of a common probing sequence and a selected one of the plurality of different frequency expansions.
摘要:
At least one channel is joined to a group of active channels in a communication system by transmitting control signals to configure respective customer premises equipment (CPE) of the active channels into a joining mode of operation, and transmitting a joining signature sequence to CPE of the joining channel over a downstream data signal path of the joining channel. A central office (CO) or other access node of the system receives correlation results from respective active channel CPE, estimates crosstalk from the joining channel into the active channels based on the correlation results, configures a precoder based on the estimated crosstalk, and adds the joining channel to the group of active channels. The channels may comprise respective subscriber lines of a DSL communication system.
摘要:
Techniques are disclosed for compensating for crosstalk using adaptation of data signals transmitted over respective channels of a communication network. In one example, a method comprises the following steps. Data is transmitted to a communication network device via a communication line during a sequence of periods. For each period of the sequence of periods, a separate value of a measure of crosstalk that was measured at the communication network device is received, each value being an average of measurements at the device of measures of crosstalk for a plurality of communication network signal subcarriers. For each individual signal subcarrier of the plurality, a matrix is updated based on the received values, the matrix being configured to precode data transmissions to the communication network device over the individual signal subcarrier. The communication network may be a DSL system, the signal subcarriers may be DSL tones, and the measure of crosstalk may be a SINR value.
摘要:
Techniques and systems for control of optical switching arrays are described. A switch array controller according to an aspect of the present invention operates so as to achieve reduced power consumption and maintain crosstalk within acceptable limits. Various rules are applied in order to insure that the desired criteria are met. In order to reduce transient effects, switching from one output to another is accomplished in a sequence chosen to maximize the number of transitions occurring in those portions of the array not carrying a signal, and to minimize the number of transitions that occur in portions of the array carrying the signal. Transitions are made in the portion of the array to which the signal will be directed, then a switch is transitioned between the old and new signal paths, and finally further transitions are made in the portion of the array within which the signal was previously directed.
摘要:
An apparatus includes a DSL transceiver configured to transit to a DSL wait state in which a power transmitted from the DSL transceiver to a local-end line is substantially reduced in response to an interruption or substantial stop at the DSL transceiver of reception of DSL communications from the local-end line. The DSL transceiver is configured to transmit to the local-end line a DSL acknowledge signal in response to receiving from the local-end line a DSL wait signal. The DSL transceiver is configured to resume to transmit DSL communications to the local-end line at a power substantially higher than the power transmitted thereto in the DSL wait state in response either to receiving from the local-end line DSL transmissions at a substantially higher power than received there from in the DSL wait state or to receiving from the local-end line a second DSL acknowledge signal.
摘要:
A method includes maintaining temporally parallel DSL data communication sessions with DSL modems of a group via a set of lines. The method includes, in response to substantially stopping to receive DSL communications from one of the DSL modems via one of the lines, transmitting a substantially reduced average power to the one of the lines and monitoring the one of the lines to determine whether DSL communications have restarted being received from the one of the DSL modems. The method also includes resuming the maintaining of the temporally parallel DSL communication sessions in response to the monitoring determining that DSL communications have restarted being received from the one of the DSL modems.