Burst transmission
A terrestrial digital video broadcasting (DVB-T) network is used to transmit IP datagrams to receiving devices using multiprotocol encapsulation (MPE). MPE datagram section and, if forward error correction (FEC) is used, MPE-FEC datagram sections may include time-slicing parameters, such as a “delta-t” parameter for specifying a time until the next burst is transmitted and a flag for indicating the end of a burst. Thus, MPE and MPE-FEC datagram sections can be transmitted in bursts. Other types of sections, however, do not include such time-slicing parameters and thus cannot usually be transmitted in bursts. Nevertheless, by assembling a burst including at least one MPE or MPE-FEC datagram section which specifies delta-t and MPE or MPE-FEC datagram section at the end of a burst which indicates its position, other types of sections can benefit from being transmitted in bursts.
1. A method comprising:
receiving data;
providing a first data structure without any time-slicing parameters for describing bursts to be transmitted in a communications network based on the data;
providing a second data structure with a set of time-slicing parameters, wherein the first and second data structures are protocol data units which are hierarchically substantially equal;
forming a burst including said first and second data structures, wherein forming the burst comprises adding the second data structure to a stream comprising the first data structure; and
transmitting the burst to the communications network, wherein the time-slicing parameters include an indication of time to a next burst, and between the burst and the next burst no data structures are transmitted in the stream.
2. The method according to claim 1 , wherein forming said burst comprises:
arranging said second data structure at an end of said burst.
3. The method according to claim 1 , including:
providing, in said second data structure, data indicating end of said burst.
4. The method according to claim 3 , wherein providing said data indicating the end of said burst comprises:
locating said data at a first predetermined position within said second data structure.
5. The method according to claim 1 , including:
providing, in said second data structure, data relating to a subsequent burst.
6. The method according to claim 1 , including:
providing, in said second data structure, data relating to an adjacent, subsequent burst.
7. The method according to claim 5 , wherein providing data relating to said subsequent burst or said subsequent adjacent burst comprises:
specifying a time until a beginning of a subsequent burst.
8. The method according to claim 5 , wherein providing data relating to said subsequent burst or said subsequent adjacent burst comprises:
specifying a beginning of a subsequent burst relative to a position of said second structure within said burst.
9. The method according to claim 2 , wherein providing said data relating to said subsequent burst or said subsequent adjacent burst comprises:
locating said data at a second predetermined position within said second data structure.
10. The method according to claim 9 , comprising:
providing a third data structure with a set of time-slicing parameters; and forming a burst including said first, second and third data structures.
11. The method according to claim 10 , including:
providing, in said third data structure, data relating to a subsequent burst.
12. The method according to claim 10 , including:
providing, in said third data structure, data relating to an adjacent, subsequent burst.
13. The method according to claim 11 , wherein providing data relating to said subsequent burst or said subsequent adjacent burst comprises:
specifying a time until a beginning of a subsequent burst.
14. The method according to claim 11 , wherein providing data relating to said subsequent burst or said subsequent adjacent burst comprises:
specifying a beginning of a subsequent burst relative to a position of said third structure within said burst.
15. The method according to claim 11 , wherein providing said data relating to said subsequent burst or said subsequent adjacent burst comprises:
locating said data at a third predetermined position within said third data structure; wherein said third predetermined position within said third data structure corresponds to said second predetermined position-within said second data structure.
16. The method according to claim 1 , comprising:
including, in said first data structure, a first identifier for identifying said first data structure as being of a first type and
including, in said second data structure, a second identifier for identifying said second data structure as being, of a second, different type.
17. The method according to claim 16 , wherein including said first and second identifiers comprises:
providing said first identifier at a fourth predetermined position within said first data structure; and
providing said second identifier at a fifth predetermined position within said second data structure;
wherein said fourth predetermined position within said first data structure corresponds to said fifth predetermined position within said second data structure.
18. The method according to claim 1 , wherein providing said second data structure comprises: providing a multiprotocol encapsulation section.
19. The method according to claim 18 , wherein providing said second data structure comprises:
formatting data using Digital Storage Media Command and Control section format.
20. The method according to claim 18 , comprising:
locating said set of time-slicing parameters within at least part of a data region formed by at least one media access control address field.
21. The method according to claim 18 , comprising:
locating said set of time-slicing parameters within at least part of a data region formed by four media access control address fields.
22. The method according to claim 1 , wherein providing said first data structure comprises: providing a motion picture experts group type 2 private section.
23. A method of operating a network element in a communications network, the method comprising:
forming a burst by adding a first data structure with a set of time-slicing parameters for describing bursts to a stream comprising a second data structure without any time-slicing parameters, wherein the first and second data structures are protocol data units which are hierarchically substantially equal; and
transmitting the burst to the communications network, wherein the time-slicing parameters include an indication of time to a next burst, and between the burst and the next burst no data structures are transmitted in the stream.
24. A method of operating a receiving device in a communications network, the method comprising:
receiving a burst including a first data structure with a set of time-slicing parameters for describing bursts and a second data structure without any timeslicing parameters, wherein the first and second data structures are protocol data units which are hierarchically substantially equal;
identifying said first data structure; and
extracting at least one time slicing parameter from said first data structure, wherein the at least one time-slicing parameter includes an indication of time to a next burst, and between the burst and the next burst no data structures are received in the stream.
25. The method according to claim 24 , wherein identifying said first data structure comprises:
inspecting a first predetermine field in each of said first and second data structures.
26. The method according to claim 24 , wherein extracting said at least one time slicing parameter from said first data structure comprises:
inspecting a second predetermined field in said first structure; and
reading from said second predetermined field, data relating to a subsequent burst.
27. The method according to claim 26 , further comprising:
storing said data relating to a subsequent burst.
28. The method according to claim 24 , further comprising:
inspecting a third predetermined field in said first structure; and
reading from said third predetermined field, data indicating end of said burst.
29. A memory embedded with computer program instructions for causing a data processing apparatus to perform the method of claim 1 when said computer program instructions are executed by said data processing apparatus.
30. An apparatus, comprising:
a receiver configured to receive data;
an encapsulator configured to form a burst by adding a first data structure with a set of time-slicing parameters for describing bursts of data to a stream comprising a second data structure without any time-slicing parameters, wherein the second data structure is based on the data, and the first and second data structures are protocol data units which are hierarchically substantially equal; and
a transmitter configured to transmit the burst to a communications network, wherein the time-slicing parameters include an indication of time to a next burst, and between the burst and the next burst no data structures are transmitted in the stream.
31. The apparatus according to claim 30 , wherein said first data structure comprises:
a multiprotocol encapsulation section.
32. The apparatus according to claim 30 , wherein said first data structure comprises:
a multiprotocol encapsulation-forward error correction section.
33. The apparatus according to claim 30 , wherein said second data structure comprises:
a motion picture experts group type 2 private section.
34. A network element comprising an apparatus according to claim 30 .
35. A handset comprising:
a receiver; and
a processor;
said handset configured to receive a burst including a first data structure with a set of time-slicing parameters for describing bursts and a second data structure without any time-slicing parameters, wherein the first and second data structures are protocol data units which are hierarchically substantially equal, to identify said first data structure; and to extract at least one time slicing parameter from said first data structure, wherein the at least one time-slicing parameter includes an indication of time to a next burst, and between the burst and the next burst no data structures are received in the stream.
36. An apparatus comprising:
means for receiving data;
means for providing a first data structure without any time-slicing parameters for describing bursts to be transmitted in a communications network based on the data;
means for providing a second data structure with a set of time-slicing parameters, wherein the first and second data structures are protocol data units which are hierarchically substantially equal;
means for forming a burst including said first and second data structures, wherein forming the burst comprises adding the second data structure to a stream comprising the first data structure; and
means for transmitting the burst to the communications network, wherein the time-slicing parameters include an indication of time to a next burst, and between the burst and the next burst no data structures are transmitted in the stream.
37. A memory embedded with computer program instructions for causing a data processing apparatus to perform the method of claim 24 when said computer program instructions are executed by said data processing apparatus.