Low power state for DSL system and devices

1. A device, comprising:

a controller to set a receiver in a power-saving state having a set spectral transmission power density, wherein the controller is configured to identify in the power-saving state first time intervals during which first signals are received by the receiver from a communication channel and to identify in the power-saving state second time intervals, which are between successive ones of the first time intervals during which no signals are received by the receiver from the communication channel.

2. The device according to claim 1 , wherein the first signals are clock synchronization signals, the device further comprising:

a synchronizing entity to synchronize a clock signal with the clock synchronization signals, wherein the synchronization entity comprises a synchronization signal input to receive the synchronization signals;

wherein the controller is configured to provide the synchronizing entity during the first time intervals in a first controlling state such that controlling of the clock signal is based on the signal received during the first time intervals at the synchronization signal input and to provide the synchronizing entity during the second time intervals in a second controlling state wherein the controlling of the clock signal is provided independent of the signal received during the second time interval at the synchronization signal input.

3. The device according to claim 2 , wherein the controller is configured to transmit information related to the duration of the first time intervals or the duration of the second time intervals or the duration of the first and second time intervals over the subscriber line.

4. The device according to claim 1 , wherein the first signals are test signals for updating at least one operation parameter and wherein the device further comprises a measurement entity to measure the received test signals and to generate updating information related to at the least one operation parameter based on the measured test signals.

5. The device according to claim 4 , wherein the measurement entity is coupled to a transmitter to transmit the updating information over the communication channel.

6. The device according to claim 1 , wherein the controller is configured to identify whether a signal received in the power-saving state is a signal to be ignored by the device.

7. A system, comprising:

a first transceiver;

a second transceiver coupled to the first transceiver via communication channel;

a first controller to set the first transceiver in a first power-saving state having a set spectral transmission power density, wherein the controller is configured to control the first transceiver to transmit in the first power-saving state first signals over a communication channel during first time intervals and to transmit no signals on the communication channel during second time intervals, which are between successive ones of the first time intervals;

a second controller to set the second transceiver in a second power-saving state being equivalent to the first power-saving state, wherein the controller is configured to identify the first time intervals during which the first signals are transmitted by the first transceiver over the communication channel and to identify the second time intervals during which no signals are transmitted by the first DSL transceiver on the communication channel.

8. The system according to claim 7 , wherein the first transceiver comprises a first measurement entity to measure at least one of the first signals and/or the second transceiver comprises a second measurement entity to measure at least one of the first signals.

9. A method, comprising:

setting a transmitter in a power-saving state having a set spectral transmission power density;

transmitting, in the power-saving state, first signals from the transmitter to a DSL receiver during first time intervals; and

transmitting, in the power-saving state, no signals from the transmitter to the receiver during second time intervals, which are between successive ones of the first time intervals.

10. The method according to claim 9 , wherein the first signals comprise clock synchronization signals or signals for updating operation parameters.

11. The method according to claim 9 , wherein transmitting in the power-saving state first signals comprises repeatedly transmitting a pilot tone on at least one frequency from the transmitter to the receiver.

12. The method according to claim 9 , further comprising updating at least one operation parameter based on the first signals, wherein the at least one operation parameter is at least one parameter of the group of parameters including a NEXT parameter, a FEXT parameter, an echo cancellation parameter, an equalizer setting parameter, a bit allocation parameter, an interleaver setting parameter, a noise protection parameter, a DSM Level 2 parameter, a gain parameter, a tone ordering parameter and a framing configuration parameter.

13. The method according to claim 9 , wherein the first time intervals are shorter than the second time intervals.

14. The method according to claim 9 , wherein the first time intervals are periodic in time.

15. The method according to claim 11 , wherein the pilot tone is transmitted on a frequency different than a frequency of the pilot tone in a non-power-saving state.

16. The method according to claim 9 , further comprising:

setting the receiver in the power-saving state;

measuring the first signal by the receiver in the power-saving state; and

updating at least one operation parameter based on the measured first signal.

17. The method according to claim 9 , wherein no user data is transmitted during the power-saving state from the transmitter to the receiver.

18. The method according to claim 9 , further comprising:

transmitting operation and maintenance information in the power-saving state.