Method for lost packet reconstruction and device for carrying out said method

1. A method for securing a data packet stream, comprising the following steps:

arranging the packets to be sent in a packet matrix of D rows and L columns;

to each row and each column of the matrix, applying an error correction function, the result of which is a correction packet enabling the reconstruction of at least one lost packet in the row, respectively the column, to which the error correction function is applied; and

sending the resulting correction packets in addition to the data packets.

2. The method according to claim 1 , wherein the correction function is also applied to the row formed by correction packets resulting from the application of the correction function to each column of the matrix generating an additional correction packet.

3. The method according to claim 1 , wherein the correction function is also applied to the column formed by correction packets resulting from the application of the correction function to each row of the matrix generating an additional correction packet.

4. The method according to claim 1 , wherein the headers of the correction packets contain a field for distinguishing whether they have been computed on a row or a column of the matrix.

5. The method according to claim 1 , wherein the correction packets are transmitted in the same stream as the data packets.

6. The method according to claim 1 , wherein the correction packets are transmitted in a different stream from the one conveying the data packets.

7. A method for reconstructing lost packets in a data packet stream, comprising the following steps:

arranging the received packets in a matrix of D rows and L columns, taking their sequence number into account; and

to each row and each column of the matrix containing at least one lost packet, applying a function for reconstructing missing packets using the received packets and the correction packet corresponding to the row or to the column.

8. The method according to claim 7 , wherein the reconstruction function can also be applied to a row or a column of correction packets using an additional correction packet generated for this purpose.

9. A transmitter device for transmitting a data packet stream over a network containing computation means generating a correction packet by applying a correction function to a group of data packets, wherein the device includes means for applying this function to rows and to columns of a matrix formed by data packets.

10. The transmitter device according to claim 9 wherein the means for applying the function comprises means for securing a data packet stream including the following:

means for arranging the packets to be sent in a packet matrix of D rows and L columns;

means for applying an error correction function to each row and each column of the matrix, the result of which is a correction packet enabling the reconstruction of at least one lost packet in the row, respectively the column, to which the error correction function is applied; and

means for sending the resulting correction packets in addition to the data packets.

11. A receiver device for receiving a data packet stream over a network containing means for computing lost packets as a function of the data packets and correction packets received, wherein the device has means for applying these computation means to rows and to columns of a matrix of data packets of the stream and to the correction packets corresponding to these rows and these columns.

12. The device according to claim 11 comprising means for reconstructing lost packets in a data packet stream, that include the following means:

means for arranging the received packets in a matrix of D rows and L columns, taking their sequence number into account; and

means for applying a function for reconstructing missing packets to each row and each column of the matrix containing at least one lost packet, the means using the received packets and the correction packet corresponding to the row or to the column.