Back channel communication

1. A method, comprising:

receiving data at customer premises equipment (CPE);

determining at least one error in the received data;

formatting the determined error for communication to a central office (CO); and

sending the formatted error to the CO via a back channel,

wherein the formatted error is sent between sync frames of a discrete multitone (DMT) superframe, and

wherein the data received at the CPE is encoded as orthogonal pilot sequences within sync frames of DMT superframes.

2. The method of claim 1 , wherein bits of the orthogonal pilot sequences are sent by the CO once every integer number of DMT superframes.

3. The method of claim 1 , wherein determining at least one error in the received data comprises measuring error samples for DMT sub-carriers.

4. The method of claim 1 , wherein determining at least one error in the received data comprises measuring error samples for DMT sub-carriers relative to specific transmitted data symbols.

5. The method of claim 1 , wherein the formatted error is sent via the back channel embodied within an embedded operational channel (EOC), wherein the EOC is further utilized for online reconfiguration commands (OLR).

6. The method of claim 5 , wherein the OLR commands comprise commands relating to one or more of: bit swapping; seamless rate adaption (SRA); and impulse noise monitor functions.

7. The method of claim 5 , wherein the data received at the CPE is encoded as orthogonal pilot sequences in a sync symbol of a DMT superframe, and wherein the EOC is decoupled from the DMT superframe.

8. The method of claim 5 , wherein a sync flag indicates initiation of a specific back channel command.

9. The method of claim 8 , wherein the sync flag is further utilized as a point of reference for identifying specific data frames relative to a position of the sync flag.

10. A method, comprising:

receiving data at customer premises equipment (CPE);

in response to determining at least one error in the received data, formatting the determined error for communication to a central office (CO); and

sending, by the CPE, the formatted error to the CO via a back channel,

wherein the formatted error is sent between sync frames of a discrete multitone (DMT) superframe, and

wherein one or more tones used for the back channel are negotiated between the CO and CPE during initialization.

11. The method of claim 10 , wherein data frames of the back channel are synchronous with the DMT superframe.

12. The method of claim 10 , further comprising determining round trip delay for the back channel during initialization.

13. A system, comprising:

means for receiving data at customer premises equipment (CPE);

means for determining at least one error in the received data;

means for formatting the determined error for communication to a central office (CO);

means for sending the formatted error to the CO via a back channel; and

means for determining round trip delay for the back channel during initialization,

wherein the formatted error is sent between sync frames a discrete multitone (DMT) superframe, and

wherein bits of orthogonal pilot sequences are sent by the CO once every integer number of DMT superframes.

14. The system of claim 13 , wherein the formatted error is sent between sync frames of DMT superframes.

15. The system of claim 13 , wherein means for determining at least one error in the received data is further configured to measure error samples for DMT sub-carriers relative to specific transmitted data symbols.

16. The system of claim 13 , wherein the formatted error is sent via the back channel embodied as an embedded operational channel (EOC), wherein the EOC is utilized for online reconfiguration commands (OLR).

17. The system of claim 16 , wherein the OLR commands comprise commands relating to one or more of: bit swapping; seamless rate adaption (SRA); and impulse noise monitor functions.