Data transmission network

Data transmission network according to one of the preceding claims, wherein a data transmission grant message comprises

• a grant message opcode, and
• an address of the selected network termination device.

Data transmission network according to one of the preceding claims, wherein

• the upstream data frames are sent from the network termination devices (8) to the line termination device (2) via the data transmission medium (7) in an upstream frequency band, and
• the downstream data frames are sent from the line termination device (2) to the network termination device (8) via the data transmission medium (7) in a downstream frequency band.

Data transmission network according to one of the preceding claims, wherein

• the downstream frequency band ranges between 1 and 3 MHz and
• the upstream frequency band ranges between 4 and 8 MHz.

Data transmission network according to one of the preceding claims, wherein each line termination device (2) comprises an MII interface (50) for the connection to a switch (4).

Data transmission network according to one of the preceding claims, wherein each network termination device (8) is connected to a passive signal splitter.

Data transmission network according to one of the preceding claims, wherein the passive signal splitter comprises

• a low-pass filter (19-i) for filtering a telephone signal, and
• a high-pass filter (12-i) for filtering an xDSL data signal.

Data transmission network according to one of the preceding claims, wherein the line termination device (2) comprises

• storing means (48) for storing the status information data of the different network termination devices (8) connected to the line termination device (2).

Data transmission network according to one of the preceding claims, wherein the storing means (48) stores the addresses of the network termination devices (8) and the corresponding numbers of the required time slots received from the network termination devices (8) in request messages.

Data transmission network according to one of the preceding claims, wherein the selection unit (66) reads the status information data stored in the storing means (48), selects the network termination devices for data transmission according to a programmed selection algorithm and activates the grant message generator (68) for generating grant messages for the selected network termination devices (8).

Data transmission network according to one of the preceding claims, wherein the xDSL transceiver (20) of the line termination device (2) includes an adaptive automatic gain control circuit (32) and an equalizer (38).

Data transmission network according to one of the preceding claims, wherein the line termination device (2) comprises

• a first storing means (73) for storing the AGC coefficients for the network termination devices (8) connected to the line termination device (2), and
• a second storing means (74) for storing equalizer coefficients for the network termination devices (8) connected to the line termination device (2).

Data transmission network according to one of the preceding claims, wherein the AGC coefficients of the selected network termination device selected by the selecting unit (66) are loaded into the AGC circuit (32) of the xDSL transceiver (20) of the line termination device (2).

Data transmission network according to one of the preceding claims, wherein the equalizer coefficients of the selected network termination device (8) selected by the selecting unit (66) are loaded into the equalizer (38) of the xDSL transceiver (20) of the line termination device (2).

Data transmission network according to one of the preceding claims, wherein the network termination device (8) comprises a grant decoder (86) for decoding messages within downstream data frames broadcasted by the line termination device (2).

Data transmission network according to one of the preceding claims, wherein the xDSL transceivers (20) are VDSL transceivers.

Data transmission network according to one of the preceding claims, wherein the impedances of the network termination devices (8) connected to the data transmission medium (7) are balanced.

Data transmission network according to one of the preceding claims, wherein eight network termination devices are connected via the data transmission medium (7) to the line termination device (8).

Data transmission network according to one of the preceding claims, wherein several line termination devices (2) are connected to a switch (4).

Data transmission network according to one of the preceding claims, wherein the switch (4) is connected to an IP backbone (5).

Line termination device comprising

• a selection unit (66) for selecting a network termination device (8) from a group of network termination devices connected to the line termination device (2) in response to a request message depending on stored status information data of the network termination devices;
• a grant message generator for generating data transmission grant messages for the selected network termination device (8), and
• an xDSL transceiver (20) for broadcasting downstream data frames including the generated grant messages via a data transmission medium (7) to the network termination devices (8).

Network termination device comprising

• a request message generator (83) for generating a data transmission request message when a data communication device (9) connected to the network termination device (8) is sending data, and
• an xDSL transceiver (20) for transmitting an upstream data frame including the generated request message via the data transmission medium (7) to a connected line termination device (2).