Layer 2 compression/decompression for mixed synchronous/asynchronous transmission of data frames within a communication network

• US 20050187777A1
• Filed: 12/14/2004
• Published: 08/25/2005
• Est. Priority Date: 12/15/2003
• Status: Active Grant

• Current Assignee: Wi-LAN Inc.
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Gerrier, Christophe, Aime, Christelle, Denis, Xavier, Lignon, Jean-Noel, Chevallier, Emmanuelle, Farineau, Jean
• Granted Patent: US 8,380,522 B2
• Time in Patent Office: Days
• US Class Current: 704/500
• CPC Class Codes: H04B 7/18543 for adaptation of transmission parameters, e.g. power control for detecting or preventing errors in the information received H04L1/00
• CPC Class Codes: H04W 88/181 Transcoding devices; Rate adaptation devices

Abstract

A device is disclosed for compressing data contained in input frames to be compressed constituted of stream frames defining portions of TRAU and signaling frames that have to be transmitted within a communication network and each of which is constituted of at least a header containing control data representative at least of the type of stream frame and where applicable payload data, certain types containing critical and/or non-critical data. The device analyzes each TRAU or signaling frame header contained in successively received input frames in order to determine its type and generates periodically compressed frames to be transmitted that are divided into first and second sections of variable size. The first section contains critical data compressed synchronously and the second section contains non-critical data compressed asynchronously.

Claims

1. A device for compressing data contained in input frames to be compressed constituted of stream frames defining portions of TRAU and signaling frames that have to be transmitted within a communication network and each of which is constituted of at least a header containing control data representative at least of the type of stream frame and where applicable payload data, certain types containing critical and/or non-critical data, which device is characterized in that it comprises analysis means adapted to analyze each TRAU or signaling frame header contained in successively received input frames in order to determine its type and compression means adapted to generate periodically compressed frames to be transmitted that are divided into first and second sections of variable size, said first section containing critical data compressed synchronously and said second section containing non-critical data compressed asynchronously.

2. The compression device claimed in claim 1 wherein said frame types are selected from the group comprising speech frames containing at least control data and critical payload data, silence frames containing at least critical control data, SID frames containing at least critical control data and non-critical payload data, and bad frames containing at least critical control data.

3. The compression device claimed in claim 1 wherein said compression means are adapted to generate a compressed frame every N input frames received during a compression cycle.

4. The compression device claimed in claim 1 wherein the sizes of said first and second sections of a compressed frame are variable and complementary.

5. The compression device claimed in claim 2 wherein said compression means are adapted to integrate said speech frames into said first sections of said compressed frames without modifying them.

6. The compression device claimed in claim 2 wherein, said speech frames containing synchronization data and control data, said compression means are adapted to integrate said speech frames into said first sections of said compressed frames after suppression of said synchronization data but without modification of said control data and said payload data.

7. The compression device claimed in claim 2 wherein, said control data being contained in said header and in an end portion of said stream frames, said compression means are adapted, once in possession of all of said control data of an SID frame or a silence frame or a bad frame, to eliminate therefrom redundant or non-significant information in order to generate a smaller relevant information word.

8. The compression device claimed in claim 7 wherein compression means are adapted to integrate said speech frames into said first sections of said compressed frames without modifying them and said compression means are adapted to constitute compressed frames comprising a first section containing said relevant information words and/or the data conveyed by said speech frames, without modification or with elimination of said synchronization data, and a header identifying the start of said compressed frame and information designating each channel of the received input frame to which belongs the data from which said relevant information or the data of said speech frame is obtained.

9. The compression device claimed in claim 2 wherein said compression means are adapted to extract said payload data contained in said SID frames, in order to store it temporarily in a buffer, and in the received signaling frames, as a function of their order of arrival, thereby constituting a string, and then to extract from the head of said string a portion whose size is selected as a function of the current variable size of said second section so as to integrate said portion into said second section of the frame currently being compressed, accompanied by a header identifying the start of said extracted portion and information designating each channel of the received input frame to which the payload data or the signaling data of said extracted string portion belongs, and finally to concatenate said second section with said first section to define a compressed frame to be transmitted.

10. The compression device claimed in claim 1 wherein said compression means are adapted to adapt the respective sizes of said first and second sections as a function of the load of said network in terms of speech frames.

11. A device for decompressing data contained in frames compressed by means of a compression device as claimed in claim 1, said decompression device comprising detection means adapted to analyze successively received compressed frames in order to separate their first and second sections, first processing means adapted to reconstitute synchronously the critical data of synchronously compressed input frames from said first received sections, second processing means adapted to reconstitute asynchronously the non-critical data of said asynchronously compressed input frames from said second received sections, and restoration means adapted to reconstruct said original input frames from reconstituted critical and non-critical data.

12. The decompression device claimed in claim 11 wherein said synchronous processing means and said asynchronous processing means operate in parallel.

13. A compressor/decompressor for a communication network comprising a compression device and a decompression device as claimed in claim 1.

14. The compressor/decompressor claimed in claim 13, comprising pre-encoder means coupled to said compression and decompression devices and adapted to apply pre-encoding to the data contained in each compressed frame as a function of the respective type of stream to which said data belongs and to apply to the data contained in each compressed and demodulated frame decoding specific to the respective type of stream to which it belongs.