Method for transmitting and receiving variable length packets based on forward error correction (FEC) coding

• US 20030226092A1
• Filed: 05/02/2003
• Published: 12/04/2003
• Est. Priority Date: 05/03/2002
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute, Kyunghee University
• Original Assignee: Electronics and Telecommunications Research Institute, Kyunghee University
• Inventors: Kim, Kyu-Heon, Kim, Hyun-Cheol, Kim, Jin-Woong, Seo, Doug-Young
• Granted Patent: US 7,409,627 B2
• Time in Patent Office: Days
• US Class Current: 714/776
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/2707 Simple row-column interleaver, i.e. pure block interleaving
• CPC Class Codes: H03M 13/353 Adaptation to the channel
• CPC Class Codes: H03M 13/6356 by repetition or insertion of dummy data, i.e. rate reduction
• CPC Class Codes: H03M 13/6508 Flexibility, adaptability, parametrability and configurability of the implementation
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0083 Formatting with frames or packets; Protocol or part of protocol for error control

Abstract

A method for transmitting variable length packets based on FEC coding. Data packets are successively and contiguously stored in a two-dimensional storage device. FEC coding is performed to generate parity packets. The parity packets are stored in the two-dimensional storage device. The data packets, offsets representing positions of the data packets in the two-dimensional storage device, types of packets, and the parity packets are then transmitted.

Claims

1. A method for transmitting variable length packets on the basis of the FEC (forward error correction) coding, comprising:

(a) receiving data packets when input data packets to be transmitted are provided; and

(b) successively storing the input data packets in a two-dimensional storage device which has a predetermined length, arranging them, and performing FEC coding to generate corresponding parity packets, and arranging the generated parity packets in the two-dimensional storage device, and transmitting the data packets, offsets that represent positions of the data packets in the two-dimensional storage device, types of packets, and the parity packets.

2. The method of claim 1, wherein the method further comprises before (a):

(c) determining whether usage of predetermined parameters needed for the FEC coding is defined; and

(d) determining the predetermined parameters and transmitting them when the usage of the predetermined parameters is not defined.

3. The method of claim 2, wherein the predetermined parameters include a length of the two-dimensional storage device, the number of the parity packets, and a factor for determining an associated packet group.

4. The method of claim 3, wherein the associated packet group is a set of the data packets and corresponding parity packets.

5. The method of claim 1, wherein (b) comprises:

(i) accumulating values of factors for determining whether to transmit the parity packets;

(ii) successively storing the input data packets in the two-dimensional storage device, and arranging them;

(iii) updating parity packets according to the input data packets;

(iv) transmitting extension data packets including information for data packet restoration and the data packets;

(v) determining whether it is time to transmit the parity packets;

(vi) transmitting the parity packets when it is the time to transmit the parity packets in (v); and

(vii) resetting the factors for determining whether to transmit the parity packets in (i).

6. The method of claim 5, wherein (vi) comprises:

determining the number of the parity packets to be transmitted;

determining whether the number of the transmitted parity packets is equal to or greater than the number of the parity packets to be transmitted;

transmitting the extension parity packet including the information for data packet restoration and the parity packets when the determined number of the transmitted parity packets is less than the determined number of the parity packets to be transmitted;

accumulating the number of the transmitted parity packets; and

resetting the parity packets and the number of the transmitted parity packets when the determined number of the transmitted parity packets is equal to or greater than the determined number of the parity packets to be transmitted.

7. The method of claim 5, wherein the factors for determining whether to transmit the parity packets in (i) include at least one of a size of the input data packets, the number of the input data packets, and time information.

8. The method of claim 5, wherein the time to transmit the parity packets in (v) is at least one of:

a time when an accumulated size of the data packets is at least equal to a predetermined size of a predetermined associated packet group,

a time when an accumulated number of the input data packets is at least equal to a predetermined number of data packets of the predetermined associated packet group, and

a time when an accumulated lapsed time of the predetermined associated packet group is at least equal to a predetermined time.

9. The method of claim 5, wherein a header of the extension packet includes information for data packet restoration.

10. The method of claim 5, wherein the information for data packet restoration includes the packets'"'"' types and the packets'"'"' offsets in the case of the data packets, and it includes the packets'"'"' types and a total size of the data packets in the associated packet group in the case of the parity packets.

11. The method of claim 10, wherein the information for data packet restoration further includes the data packets'"'"' offsets in the case of the parity packets.

12. The method of claim 5, wherein the parity packets are updated by calculating the data arranged in the two-dimensional storage device per a predetermined length.

13. The method of claim 6, wherein the number of the parity packets to be transmitted is determined according to a state of a channel on which the packets will be transmitted.

14. The method of claim 1, wherein successively storing the data packets in the two-dimensional storage device and arranging them represents respectively connecting the data packets and storing them in the two-dimensional storage device.

15. A method for receiving variable length packets on the basis of the FEC (forward error correction) coding, comprising:

(a) receiving packets, successively storing them in a two-dimensional storage device which has a predetermined storage length, and arranging the same when the extension packet is provided; and

(b) performing FEC decoding to restore data packets from the received extension packet, and delivering them to an upper layer.

16. The method of claim 15, wherein the method further comprises before (a):

(c) determining whether usage of predetermined parameters needed for the FEC decoding is defined; and

(d) receiving the predetermined parameters from a transmitter when the usage of the predetermined parameters is not defined.

17. The method of claim 15, wherein (a) comprises:

(i) receiving the extension packet;

(ii) determining whether the received extension packet is an extension data packet or an extension parity packet;

(iii) separating the data packet and information for data packet restoration when the received extension packet in (ii) is an extension data packet including the data packet;

(iv) separating the parity packet and information for data packet restoration when the received extension packet in (ii) is an extension parity packet including the parity packet; and

(v) sequentially arranging the separated data packet and the parity packet in (iii) or (iv) in the predetermined two-dimensional storage device.

18. The method of claim 15, wherein (b) comprises:

(i) determining whether it is time to deliver the associated packet group to an upper layer; and

(ii) delivering the separated data packets to the upper layer when it is determined to be the time to deliver the associated packet group to an upper layer.

19. The method of claim 18, wherein the time to deliver the associated packet group to the upper layer may be a time when the last packet in the associated packet group or a packet in a subsequent associated packet group arrives, or a time when a predetermined time has lapsed.

20. The method of claim 18, wherein (ii) comprises:

(ii-i) determining whether the separated data packets have a lost portion;

(ii-ii) determining whether the data packet has a restorable portion when the data packets have a lost portion;

(ii-iii) restoring the lost data packets when the lost portion is restorable in (ii-ii);

(ii-iv) determining whether all lost portion can not be restored in (ii-iii);

(ii-v) delivering lost positions to the upper layer when it is determined that no restorable portion remains in (ii-ii) or when a portion is not restored in (ii-iv); and

(ii-vi) delivering the received data packets to the upper layer when no data packet is lost in (ii-i), or delivering the received data packets including the restored data packets to the upper layer when data are restored in (ii-iii).

21. The method of claim 15, wherein successively storing the packets in the two-dimensional storage device and arranging the same represents connecting the data packets and storing them in the two-dimensional storage device so that the corresponding storage length may be a storage length of the two-dimensional storage device.

22. A method for transmitting variable length packets using FEC (forward error correction) coding, comprising:

(a) receiving data packets to be transmitted;

(b) successively storing the data packets contiguously in a two-dimensional storage device,

(c) performing FEC coding to generate corresponding parity packets,

(d) successively storing the generated parity packets contiguously in the two-dimensional storage device; and

(e) transmitting the data packets, offsets that represent positions of the data packets in the two-dimensional storage device, types of packets, and the parity packets.

23. A method for receiving variable length packets using FEC (forward error correction) coding, comprising:

(a) receiving packets, successively and contiguously storing them in a two-dimensional storage device when an extension packet is provided; and

(b) performing FEC decoding to restore data packets from the received extension packet, and delivering them to an upper layer.