The invention relates to a method for data repair in a system capable of one-to-many transmission. The method comprises transmitting data from a sender to at least one receiver and provides for various sender driven or receiver driven repair methods of missing data.
1. Method comprising:
transmitting data from a sender to at least one receiver in a one-to-many fashion;
providing sender driven or receiver driven repair of missing data, concerning data missing at the receiver, wherein both the sender driven and receiver driven repair comprise sending a repair request from said receiver to said sender, and wherein the method further comprises:
distributing messaging concerning repair over a period of time to avoid congestion.
2. The method of claim 1 , wherein repair is implemented in a repair session comprising one of the following:
re-transmitting missing data in total;
re-transmitting only a part of missing data; and
repeating original transmission in a whole.
3. The method of claim 1 , wherein an error rate parameter is transmitted from sender to receiver to be used as a threshold in requesting repair of missing data.
4. The method of claim 3 , wherein said error rate parameter is used to calculate the threshold in a time and/or data window.
5. The method of claim 1 , wherein the method comprises indicating to receivers that a session or part of it will be re-transmitted in a point-to-multipoint fashion.
6. The method of claim 5 , wherein said indication is implemented with the aid of a point-to-multipoint repair token.
7. The method of claim 1 , wherein the method comprises generating random or pseudo-random time dispersion of repair requests to be sent from receiver(s) to sender.
8. The method of claim 7 , wherein the method provides for statistically uniform distribution over a relevant period of time.
9. The method of claim 1 , wherein the method comprises using receiver roles.
10. The method of claim 9 , wherein one or more of the roles comprise a back-off time given by offset time and random time period.
11. The method of claim 9 , wherein one or more of the roles comprise flag-holder behaviour.
12. The method of claim 1 , wherein the method comprises sharing time parameter(s) and/or data parameter(s) and/or error parameter(s) between sender and receiver by pre-configuring.
13. The method of claim 1 , wherein the method comprises indicating from server to receiver, after receipt of a repair request, that repair will be performed only later.
14. The method of claim 1 , wherein the method comprises prioritizing between different repair methods.
15. The method of claim 14 , wherein the method comprises first starting point-to-multipoint repair followed by point-to-point repair.
16. The method of claim 1 , wherein the method comprises using an initiation point for repair sessions/signalling, said initiation point being selected from a group comprising: end of a session, object end, object threshold and end of a session group.
17. The method of claim 1 , wherein the method comprises delaying sending of a repair request at the receiver.
18. The method of claim 1 , wherein said repair request is delayed with a pre-determined amount of time.
19. The method of claim 1 , wherein a repair request is performed only when the need to consume the data at the receiver arises.
20. The method of claim 1 , wherein a maximum repair availability time is provided.
21. The method of claim 19 , wherein the method further comprises taking into account a position of a first loss in data stream.
22. The method of claim 1 , wherein a recovery time is calculated and used in missing data repair.
23. The method of claim 1 , wherein a separate repair session is requested and/or started before an initial multicast/broadcast transmission has ended.
24. The method of claim 1 , wherein the method comprises calculating a repair request suppression time to wait before requesting repair.
25. Apparatus comprising:
means for receiving data transmitted by a sender; in a one-to-many fashion;
means for sender driven or receiver driven repair of missing data, concerning data missing at the receiver device; means for sending a repair request to the sender; and
means for distributing messaging concerning repair over a period of time to avoid congestion.
26. Apparatus comprising:
means for transmitting data to at least one receiver; in a one-to-many fashion;
means for sender driven or receiver driven repair of missing data, concerning data missing at the receiver;
means for receiving a repair request from the receiver; and
means for distributing messaging concerning repair over a perioid of time to avoid congestion.
27. System comprising:
means for transmitting data from said sender device, via said network, to said at least one receiver device; in a one-to-many fashion;
means for providing sender driven or receiver driven repair of missing data, concerning data missing at the receiver device;
means for sending a repair request from the receiver to the sender; and
means for distributing messaging concerning repair over a period of time to avoid congestion.
28. Computer readable medium having stored thereon a computer proaram executable in a receiver device, the computer-program comprising:
program code for causing the receiver device to receive data transmitted by a sender in a one-to-many fashion;
program code for sender driven or receiver driven repair of missing data, concerning data missing at the receiver device, wherein both the sender driven and receiver driven repair comprise sending a repair request from the receiver to the sender; and
program code for distributing messaging concerning repair over a period of time to avoid congestion.
29. Computer readable medium having stored thereon a computer program executable in a sender device, the computer program comprising:
program code for causing the sender device to transmit data to at least one receiver in a one-to-many fashion;
program code for sender driven or receiver driven repair of missing data, concerning data missing at the receiver, wherein both the sender driven and receiver driven repair comprise sending a repair request from the receiver to the sender; and
program code for distributing messaging concerning repair over a period of time to avoid congestion.
30. Apparatus, comprising:
a receiver for receiving data transmitted in a one-to-many fashion by a sender device, wherein the apparatus is configured for sender driven or receiver driven repair of missing data, concerning data missing at the receiver device, the apparatus further comprising:
a transmitter for sending a repair request to the sender device, wherein the apparatus is further configured for distributing messaging concerning repair over a period of time to avoid congestion.
31. The apparatus of claim 30 , wherein the apparatus is configured to use an error rate parameter received from the sender device as a threshold in requesting repair of missing data.
32. The apparatus of claim 30 , wherein the apparatus is configured to use a receiver role or roles.
33. The apparatus of claim 30 , wherein the apparatus is configured to delay sending the repair request with a pre-determined amount of time.
34. The apparatus of claim 30 , wherein the apparatus is configured to perform said repair request only when the need to consume the data at the apparatus arises.
35. The apparatus of claim 34 , wherein the apparatus is configured take into account a position of a first loss in a data stream.
36. The apparatus of claim 30 , wherein the apparatus is configured to calculate a recovery time to be used in said repair of missing data.
37. The apparatus of claim 30 , wherein the apparatus is configured to request a separate repair session and/or a separate repair session to be started before an initial multicast/broadcast transmission has ended.
38. The apparatus of claim 30 , wherein the apparatus is configured to calculate a repair request suppression time to wait before requesting repair.
39. Apparatus, comprising:
a transmitter for transmitting data in a one-to-many fashion to at least one receiver device, wherein the apparatus is configured for sender driven or receiver driven repair of missing data, concerning data missing at a receiver device, the apparatus further comprising:
a receiver for receiving a repair request from said receiver device, wherein the apparatus is further configured for distributing messaging concerning repair over a period of time to avoid congestion.
40. The apparatus of claim 39 , configured to transmit to a receiver device an error rate parameter to be used as a threshold in requesting repair of missing data.
41. The apparatus of claim 39 , configured to indicate to said receiver device that a session or part of it will be re-transmitted in a point-to-multipoint fashion.
42. The apparatus of claim 41 , configured to so indicate with the aid of a point-to-multipoint repair token.
43. The apparatus of claim 39 , wherein the apparatus is configured for using receiver roles.
44. The apparatus of claim 39 , configured to first start point-to-multipoint repair followed by point-to-point repair.
45. The apparatus of claim 39 , configured to use an initiation point for repair sessions/signalling, said initiation point being selected from a group comprising: end of a session, object end, object threshold and end of a session group.
46. The apparatus of claim 39 , wherein the apparatus is configured to provide a maximum repair availability time.
47. The apparatus of claim 39 , configured to start a separate repair session before an initial multicast/broadcast transmission has ended.