Power saving mode for multi-carrier transmission

1. A method for multi-carrier data transmission, wherein carrier frequencies of each carrier of a set of carriers differ from one carrier to another, comprising:

using, in a first transmission mode, all carriers of the set of carriers for payload data transmission, and

in a second transmission mode, refraining from transmitting payload data on at least one of the carriers of the set of carriers and reducing transmission power of the at least one of the carriers,

using, in the first transmission mode, a further set of carriers different from the set of carriers and having different carrier frequencies for transmission of overhead data, and

in the second transmission mode transmitting a load data via the further set of carriers which, in the first transmission mode, would be transmitted via the set of carriers.

2. The method of claim 1 , further comprising:

switching between the first transmission mode and the second transmission mode based on an amount and/or type of data to be transmitted.

3. The method of claim 2 , wherein the method further comprises:

providing a retransmission layer, providing a TPS-TC layer performing a rate decoupling above the retransmission layer, the retransmission layer generating data transfer units,

identifying data transfer units as idle if they do not contain data from layers above the TPS-TC layer, and

switching from the first transmission mode to the second transmission mode based on identified idle data transfer units.

4. The method of claim 3 , wherein the multi-carrier transmission is discrete multitone modulation, the method further comprising:

aligning data transfer units with discrete multitone symbols.

5. The method of claim 3 ,

wherein the method is performed according to ITU-T G998.4.

6. The method of claim 1 , wherein reducing transmission power for at least some of the carriers comprises switching off the at least some of the carriers.

7. The method of claim 1 , wherein reducing transmission power for at least some of the carriers comprises setting gains of the at least some of the carriers to a predetermined value or to values depending on a signal-to-noise-ratio at a receiver side.

8. The method of claim 1 , wherein the payload data transmitted via the further set of carriers in the second transmission mode comprises control data from layers higher than a TPS-TC layer and/or service data in an amount below a threshold value.

9. The method of claim 8 , wherein the control data is provided to the further set of carriers without using at least one of a TPS-TC layer and a retransmission layer.

10. The method of claim 1 , wherein the further set of carriers transmits data processed via a first latency path including forward error correction and the set of carriers is used for transmitting data processed via a second latency path.

11. The method of claim 1 , further comprising sending a control message when switching between the first transmission mode and the second transmission mode.

12. A communication device for multi-carrier data transmission, comprising communication circuitry which is configured to use,

in a first transmission mode, a first set of carriers for payload data transmission, and a further set of carriers different from the first set of carriers for overhead data transmission,

and,

in a second transmission mode, a second set of carriers for payload data transmission,

wherein the second set of carriers is a subset of the first set of carriers that does not comprise at least one of the carriers of the first set of carriers,

wherein, in the second transmission mode, transmission power of the at least one carrier of the first set of carriers that is not comprised in the second set of carriers is reduced with respect to transmission power in the first transmission mode, and

wherein, in the second transmission mode, payload data is transmitted via the further set of carriers which, in the first transmission mode, would be transmitted via the first set of carriers.

13. The communication device of claim 12 , wherein the communication device comprises a TPS-TC layer, a retransmission layer below the TPS-TC layer and a PMS-TC layer below the retransmission layer, the PMS-TC layer comprising a first latency path for overhead data and a second latency path for data received from the retransmission layer at least in the first transmission mode.

14. A method, comprising:

allocating, by a communication device, a set of carriers for use for communication of data;

communicating data, in a first transmission mode, on all carriers associated with the set of carriers; and

communicating data, in a second transmission mode, on less than all carriers associated with the set of carriers,

providing a retransmission layer, providing a TPS-TC layer performing a rate decoupling above the retransmission layer the retransmission layer generating data transfer units,

identifying data transfer units as idle if they do not contain data from layers above the TPS-TC layer, and

switching from the first transmission mode to the second transmission mode based on identified idle data transfer units.

15. The method according to claim 14 , wherein the data is payload data comprising control data from one or more layers above the TPS-TC (Transmission Protocol-Specific Transmission Convergence) layer.

16. The method according to claim 14 , further comprising reducing power, in the second transmission mode, associated with one or more of the carriers of the set of carriers.

17. The method according to claim 14 , further comprising switching between the first transmission mode and the second transmission mode based on an amount and/or type of data to be transmitted.

18. The method according to claim 16 , reducing transmission power comprises setting gains of the one or more of the carriers of the set of carriers to a predetermined value or to values depending on a signal-to-noise-ratio at a communication device.