Transmission of data with forward error correction information

1. A method of transmitting content to one or more receiving devices comprising:

generating recovery data using a processor for use in forward error correction of the content;

transmitting the content from a transmitter configuration to said receiving devices over a first communication channel; and

in response to a request from one or more of said receiving devices, transmitting the recovery data from the transmitter configuration to said one or more receiving devices over a second communication channel.

2. A method according to claim 1 , wherein the first communication channel is provided by a first communication network and the second communication channel is provided by a second communication network.

3. A method according to claim 2 , wherein the first communication network is uni-directional.

4. A method according to claim 1 , wherein the first communication channel and the second communication channel are logical channels in a first communication network.

5. A method according to claim 4 , wherein the first communication network is uni-directional.

6. A method of receiving content from a source comprising:

receiving, at a receiving device, one or more content data packets from a first communication channel;

determining, at the receiving device, whether the received content data packets contain errors and, if so, whether said errors are correctable; and

in response to a positive determination, sending a request for recovery data from the receiving device to the source, receiving said recovery data at the receiving device from a second communication channel and using the recovery data for performing forward error correction of the content data packets.

7. A method according to claim 6 , wherein the first communication channel is provided by a first communication network and the second communication channel is provided by a second communication network.

8. A method according to claim 7 , wherein the first communication network is uni-directional.

9. A method according to claim 6 , wherein the first communication channel and the second communication channel are logical channels in a first communication network.

10. A method according to claim 9 , wherein the first communication network is uni-directional.

11. An apparatus for transmitting content to one or more receiving devices comprising:

a processor configured to generate recovery data for use in forward error correction of the content;

a transmitter configuration operable to transmit the content to said receiving devices over a first communication channel and to transmit the recovery data to one or more of said receiving devices over a second communication channel; and

an input interface for receiving requests from said one or more receiving devices;

wherein the transmitter configuration is operable to transmit the recovery data over the second communication channel in response to the reception of a request.

12. An apparatus according to claim 11 , further configured to transmit the content over a first communication network and to transmit the recovery data over a second communication network.

13. An apparatus according to claim 12 , including a content provider for providing said content in packets for transmission through the first network, and a recovery data provider for providing said recovery data in packets for transmission through the second network.

14. A communication system comprising an apparatus according to claim 11 .

15. An apparatus for receiving content from a source, comprising:

a receiver operable to receive one or more content data packets from a first communication channel; and

a processor configured to determine whether the content data packets contain errors and, if so, whether said errors are correctable, and, in response to a positive determination, to send a request for recovery data to the source and, in response to the reception of the recovery data from a second communication channel, to perform forward error correction using said recovery data.

16. An apparatus according to claim 15 , wherein the first communication channel is provided by a first communication network and the second communication channel is provided by a second communication network.

17. An apparatus according to claim 15 , comprising a mobile telephone handset.

18. A communication system comprising an apparatus according to claim 15 .