ENCODING AND DECODING METHOD, AND ENCODING AND DECODING DEVICES WITH A TWO-STAGE ERROR PROTECTION PROCESS

• US 20110131474A1
• Filed: 02/07/2011
• Published: 06/02/2011
• Est. Priority Date: 07/27/2004
• Status: Active Grant

• Current Assignee: Nokia Solutions and Networks GmbH & Co. KG (Nokia Corporation)
• Original Assignee: Nokia Siemens Networks GmbH & Company KG (Nokia Corporation)
• Inventors: PANDEL, Jürgen, Wagner, Marcel
• Granted Patent: US 8,601,343 B2
• Time in Patent Office: Days
• US Class Current: 714/776
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0065 Serial concatenated codes

Abstract

An encoding method and device are provided for a series of data packets transmitted in the framework of a combined streaming and downloading application by a two-stage error protection process and only one unidirectional transmission channel. A partial block of successive data packets is protected against some transmission errors occurring during streaming with the aid of a first error protection process while all data packets are protected against the transmission errors that can remain after streaming is completed with the aid of a second error protection process. In a decoding process, a series of data packets that are encoded according to the encoding are decoded.

Claims

1. A method of streaming media content in the form of a series of data packets transmitted via at least one unidirectional transmission channel comprising:

dividing the series of data packets into partial blocks, each being formed from a plurality of successive data packets, and applying a first error protection process to encode each partial block of successive data packets to protect the data packets against transmission errors occurring during streaming of the media content;

applying a second error protection process to encode all data packets to protect the data packets against transmission errors occurring during streaming of the media content;

applying a first decoding process corresponding to the first error protection process to a partial block and if the partial block contains no errors, providing the partial block for play back of the content represented by the partial block;

in the event that reconstruction of the data packets of the partial block by applying the first decoding process is unable to provide error-free reconstructed data packets, storing the data packets instead of playing back the content represented by the partial block; and

applying a second decoding process corresponding to the second error protection process to correct errors in order that the data packets comprising the media content, once downloaded, are stored free of any errors.

2. The method as claimed in claim 1, wherein at least one of the following error protection algorithms is used for the first and/or second error protection process:

EXOR parity code;

Reed-Solomon code; and

Low density parity check code.

3. The method as claimed in claim 1, wherein the quantity of error detection packets in the partial block is determined as a function of a specifiable delay, taking account of a transmission rate, a redundant block length and an error detection packet length.

4. The method as claimed in claim 1, wherein a characteristic value is created for each data packet by a statistical method, the characteristic value represents an importance of the respective data packet with respect to at least one other data packet, the quantity of data packets for the partial block is selected in such a way that a sum of characteristic values of successive data packets within the respective partial block reaches at least one specifiable threshold.

5. The method as claimed in claim 1, wherein an error protection block is formed for each partial block, the error protection block having encoded data packets provided with unequal error protection.

6. The method as claimed in claim 5, wherein error detection data packets containing important information have more error protection and error detection data packets containing less important information have less error protection.

7. The method as claimed claim 1, wherein an error protection block is formed for each partial block in such a way that a specifiable number of erroneous error detection packets can be corrected within the error protection block by the first error protection process.

8. The method as claimed in claim 1, wherein at least one erroneous error detection packet within an error protection block formed for each partial block can be corrected by the first error protection process.

9. The method as claimed in claim 1, wherein at least two successive erroneous error detection packets within an error protection block formed for each partial block can be corrected by the first error protection process.

10. The method as claimed in claim 1, wherein a complete error protection block is created by applying the second error protection process in such a way that a greater number of erroneous error detection data packets can be corrected with the second error protection process than with the first error protection process.

11. The method as claimed in claim 1, wherein a complete error protection block is created by applying the second error protection process in such a way that it has segments formed by reordering error detection packets, each segment being formed such that errors are separately corrected within the segment.

12. The method as claimed in claim 1, wherein during the transmission of error protection blocks, the error detection packets are transmitted via a first transmission channel and redundant blocks are transmitted via a second transmission channel.

13. The method as claimed in claim 12, wherein the error detection packets and the redundant blocks are transmitted in synchronization in such a way that the redundant block of the respective error protection block is present at a receiver not later than a time of reception of a last error detection packet of the respective error protection block.

14. The method as claimed in claim 2, wherein a characteristic value is created for each data packet by a statistical method, the characteristic value represents an importance of the respective data packet with respect to at least one other data packet, the quantity of data packets for the partial block is selected in such a way that a sum of characteristic values of successive data packets within the respective partial block reaches at least one specifiable threshold.

15. The method as claimed in claim 1, wherein, play back occurs while partial blocks are being transmitted.

16. A system for streaming media content in the form of a series of data packets transmitted via at least one unidirectional transmission channel comprising:

a partial block generator to divide the series of data packets into partial blocks, each being formed from a plurality of successive data packets, and apply a first error protection process to encode each partial block of successive data packets to protect the data packets against transmission errors occurring during streaming of the media content;

an encoder to apply a second error protection process to all data packets to protect the data packets against transmission errors occurring during streaming of the media content;

a block handler to apply a first decoding process corresponding to the first error protection process to a received partial block and if the partial block contains no errors, to provide the partial block for play back of the content represented by the partial block, and if reconstruction of the data packets of the partial block by applying the first decoding process is unable to provide error-free reconstructed data packets, reconstructed data packets are provided for storing instead of playing back the content represented by the partial block; and

a decoder to apply a second decoding process corresponding to the second error protection process to correct errors in order that the data packets comprising the media content, once downloaded, are capable of being stored free of any errors.

17. A decoding device for decoding streaming media content in the form of a series of data packets received via at least one unidirectional transmission channel, the series of data packets comprising a series of partial blocks, comprising:

a block handler to apply a first decoding process corresponding to the first error protection process to a received partial block and if the partial block contains no errors, to provide the partial blocks for play back of the content represented by the partial block, and if reconstruction of the data packets of the partial block by applying the first decoding process is unable to provide error-free reconstructed data packets, reconstructed data packets are provided for storing instead of playing back the content represented by the partial block; and

a storage handler to apply a second decoding process corresponding to the second error protection process to correct errors in order that the data packets comprising the media content, once downloaded, are capable of being stored free of any errors.