Abstract:
A method and apparatus for transmitting data from a transmitter device to one or more receiver devices connected to the transmitter device via a respective wire connection, the transmitter device being operable to transmit signals onto the wire connections and a further wire connection at different tones, the method comprising: for each tone, allocating signals transmitted on the further wire connection as supporting signals for a particular wire connection, and measuring electromagnetic coupling between the further wire connection and that particular wire connection; using the measurements, determining a power allocation for transmitting a supporting signal on the further wire connection; for one or more of the tones: transmitting a signal onto the particular wire connection, and transmitting a supporting signal onto the further wire connection at the determined transmission power, thereby to cause crosstalk interference in the particular wire connection.
Abstract:
Apparatus for communicating data between a transmitter device 16 and a first 51 and a second 52 receiver device, the receiver devices being connected, in use, to the transmitter device via a first 21 and a second 22 pair of wires respectively. Each receiver device is operable to receive signals detected as a change over time in the potential difference across the local ends of each respective pair of wires extending between the respective receiver device and the transmitter device, and the transmitter device is operable to transmit signals onto the wires at the transmitter ends thereof in order to transmit signals via a direct differential mode to each respective receiver via its respective pair of wires. The transmitter device is additionally operable to transmit signals to both receivers via a single common indirect channel and comprises: a channel estimator 1670, 1680, 1690 for estimating the extent of coupling between the common indirect channel and each of the receiver devices based on readings received by the transmitter device from the receiver devices; and a processor 1690 for determining a plurality of weighting values in dependence upon the estimated extents of the couplings; the transmitter 16 being operable to transmit a first signal via the direct differential mode over the first pair 21, to transmit a second signal via the direct differential mode over the second pair 22 and to transmit a combined signal onto the indirect channel, wherein the combined signal comprises a weighted sum of the first and second signals, the weighting being done in accordance with the determined weighting values; and wherein the transmitter further comprises a precoder 1640 for precoding the first, second and combined signals to pre-compensate them for the expected effects of cross- talk from the other ones of these signals, wherein the pre-coding of each signal, including the first and the second signals, is performed in dependence upon the determined weighting values.
Abstract:
A method and apparatus for transmitting data from a transmitter device to one or more receiver devices connected to the transmitter device via a respective wire connection, the transmitter device being operable to transmit signals onto the wire connections and a further wire connection at different tones, the method comprising: for each tone, measuring electromagnetic coupling between the further wire connection and each of the wire connections and using the measurements, identifying a wire connection that most strongly receives crosstalk interference from the further wire connection; based on the identifications, for each tones, allocating signals transmitted on the further wire connection as supporting signals for a particular wire connection; transmitting a first signal onto the particular wire connection that has been allocated a supporting signal; and transmitting a second signal onto the further wire connection, thereby to cause crosstalk interference in the particular wire connection transmitting the first signal.
Abstract:
A method of transmitting data from a transmitter device 16 to a plurality of receiver devices 51, 52, each of which is connected to the transmitter device 16 via a respective wire connection 21, 22 the method comprising transmitting a common signal onto all or both of the respective wire connections 21, 22 and using a multiple access technique to enable respective virtual data channels to be generated for transmitting data from the transmitter device 16 to each of the receiver devices 21, 22 via its own respective virtual data channel.
Abstract:
The invention relates to a method, and a device for performing said method, for allocating power levels to a transmission in a DSL network, the method comprising the steps of: identifying a first and second geographical region as being associated with a subscriber line in the DSL network; defining a first spectral mask having a first set of power levels over a range of frequencies, wherein the first set of power levels are tailored according to a Radio Frequency, RF, environment of the first geographical region; defining a second spectral mask having a second set of power levels over the range of frequencies, wherein the second set of power levels are tailored according to an RF environment of the second geographical region; and constructing a transmit spectral mask for the subscriber line, the transmit spectral mask based on a combination of the first and second spectral masks, including, for each frequency in the range of frequencies, using the minimum power level for that frequency from the first and second spectral masks.
Abstract:
A method and apparatus for transmitting data in a communication system comprising a transmitter (16) and receivers (41-44), each receiver (41-44) being 5 connected to the transmitter (16) via a communication channel (21-28), the method comprising: i) precoding the data for transmission on the channels (21- 28) to provide first precoded data; ii) using the first precoded data, for each channel (21-28), computing a number of bits to be allocated to that channel (21- 28); iii) determining that the bit allocation does not satisfy one or more criteria; 10 iv) ranking the channels (21-28) in an order based on channel properties; v) discarding for use as a direct channel, one or more channels (21-28) based on the ranking; vi) precoding the data for transmission on the channels (21-28) accounting for the discarded channels to provide second precoded data; and vii) transmitting, by the transmitter, the second precoded data on the channels 15 (21-28).
Abstract:
An access network including twisted metallic pair connection to transmit data, including an access network modem connected to the twisted metallic pair connection and a broadband speed estimation tool including a web server and a line length, further deployment factors and speed determiner module. The web server to receive a deployment indication identifying a twisted metallic pair connection, an expected type of deployment and a type of DSL protocol of transmission. The line length, further deployment factors and speed determiner module is operable to determine, from the identification of the twisted metallic pair and the type of DSL protocol, an estimate of the length of the twisted metallic pair and, from the expected type of deployment, associated deployment factors, an estimated potential achievable data rate at which the DSL protocol can transmit data over the twisted metallic pair in dependence upon the determined estimate of the length and in dependence upon the determined associated deployment factors and the type of DSL protocol. The access network comprises a line management subsystem which determines an appropriate value for each configuration parameters in dependence upon the estimated data rate and causes the modem to operate in accordance with the determined values of the configuration parameters.
Abstract:
A Digital Subscriber Line Access Multiplexer (DSLAM) (20) is modified to monitor when a line (19) synchronises (i.e. sets up a DSL connection) and to automatically generate a notification to be sent to a management device (100) of the access network if the rate has changed from the last time the line synchronised.
Abstract:
There is herein disclosed a method of processing a plurality of multiple-input multiple-output (MIMO) signals for transmission over a plurality of communication channels, the method comprising: precoding the plurality of signals prior to transmission, the precoding incorporating channel state information in relation to the plurality of communication channels, the precoding further incorporating: a priority ranking of a first channel of the plurality of communication channels relative to a second channel of the plurality of communication channels; and/or an error rate required by a channel of the plurality of communication channels; and/or an amount of noise experienced by a channel of the plurality of communication channels.
Abstract:
A network node for use in a hybrid fibre-copper access network, wherein the node comprises DSL and reverse-power feed functionality. The node has a substantially cylindrical shape such that it receives an input metallic cable at a first end, an output metallic cable at a second end and an optical fibre cable which is received at a point along the body of the node.