초록 ▼

The invention relates to the generation of error correction data for available data packets and to the reconstruction of missing data packets based on available data packets and available error correction data. In order to enable an efficient error correction, the data packets are distributed at an

The invention relates to the generation of error correction data for available data packets and to the reconstruction of missing data packets based on available data packets and available error correction data. In order to enable an efficient error correction, the data packets are distributed at an encoding end to at least one block of data symbols, each data symbol being of equal size. Then all data symbols of a respective block are used in an encoding operation for forming a respective one of at least one error correction symbol for this block. At a decoding end, received data packets are distributed again to a block of data symbols and missing data packets are reconstructed based on these data symbols and on error correction symbols associated to the block.

대표청구항 ▼

What is claimed is: 1. A method for generating error correction data, the method comprising: receiving one or more data packets at a first device from a second device; distributing the one or more data packets into a block at the first device, wherein the block comprises equal size data symbols arr

What is claimed is: 1. A method for generating error correction data, the method comprising: receiving one or more data packets at a first device from a second device; distributing the one or more data packets into a block at the first device, wherein the block comprises equal size data symbols arranged column by column to form a matrix; and forming one or more error correction symbols for the block, wherein each of the one or more error correction symbols is formed using all of the data symbols of the block in an encoding operation at the first device. 2. The method according to claim 1, wherein the encoding operation comprises a Low Density Parity Check erasure code for forming said one or more error correction symbols. 3. The method according to claim 1, wherein the one or more error correction symbols are generated at an application layer and wherein the one or more data packets comprise Realtime Transfer Protocol packets. 4. The method according to claim 1, wherein the one or more error correction symbols are generated at a link layer and wherein the one or more data packets comprise Internet Protocol datagrams. 5. The method according to claim 1, wherein the one or more error correction symbols are generated for a Multimedia Broadcast Multicast Services streaming session. 6. The method according to claim 1, further comprising determining a size of the block. 7. The method according to claim 1, further comprising encapsulating the one or more error correction symbols for the block in at least one error correction packet. 8. The method according to claim 1, further comprising adding to each of the one or more data packets an information item which indicates a length of the one or more data packets. 9. A method for reconstructing missing data packets, the method comprising: receiving one or more data packets at a first device from a second device; receiving one or more error correction data packets at the first device from the second device; determining if all of the one or more data packets were received at the first device; if all of the one or more data packets were not received, evaluating positioning information of the one or more data packets; distributing the one or more data packets to a block of data symbols, wherein the block of data symbols comprises equal size data symbols and each data packet is associated with a known position in the block of data symbols; distributing the one or more error correction data packets to a block of error correction symbols; and recovering the one or more data packets that were not received based on the data symbols and based on the error correction symbols. 10. A method according to claim 9, further comprising extracting the one or more data packets and the one or more recovered data packets from the block of data symbols, based on an information item in each data packet indicating a length of the data packet. 11. A device for generating error correction data, the device comprising: a communication interface configured to receive one or more data packets; and a processing module configured to cause the device to: distribute the one or more data packets into a block, wherein the block comprises equal size data symbols arranged column by column to form a matrix; and form one or more error correction symbols for the block, wherein each of the one or more error correction symbols is formed using all of the data symbols of the block in an encoding operation. 12. The device of claim 11, wherein the encoding operation comprises a Low Density Parity Check erasure code for forming said one or more error correction symbols. 13. A device for reconstructing missing data packets, the device comprising: a communication interface configured to receive one or more data packets and one or more error correction data packets; and a processing module configured to cause the device to determine if all of the one or more data packets were received; if all of the one or more data packets were not received, evaluate positioning information of the one or more data packets; distribute the one or more data packets to a block of data symbols, wherein the block of data symbols comprises equal size data symbols and each data packet is associated to a known position in the block of data symbols; distribute the one or more error correction data packets to a block of error correction symbols; and recover the one or more data packets that were not received based on the data symbols and based on the error correction symbols. 14. The device of claim 13, wherein the one or more data packets are Media RTP packets and the one or more error correction data packets are FEC RTP packets. 15. The device of claim 13, wherein the block of data symbols comprises a media data matrix and the block of error correction symbols comprises a FEC data matrix.