Protocol message compression in a wireless communications system

• US 20030233478A1
• Filed: 06/17/2002
• Published: 12/18/2003
• Est. Priority Date: 06/17/2002
• Status: Active Grant

• Current Assignee: Mooi Choo Chuah, Subhasis Laha, Tingfang Ji
• Original Assignee: Mooi Choo Chuah, Subhasis Laha, Tingfang Ji
• Inventors: JI, Tingfang, Chuah, Mooi Choo, Laha, Subhasis
• Granted Patent: US 7,143,191 B2
• Time in Patent Office: Days
• US Class Current: 709/247
• CPC Class Codes: H03M 7/3088 employing the use of a dictionary, e.g. LZ78
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method, apparatus, system, and computer software for compressing and decompressing a message for transmission. The method of compressing a text message for transmission may include parsing text strings and encoding numerical values with a binary representation and analyzing values of the text strings and populating a session specific codebook with partial strings from the values. The method of compressing a message for transmission may also include parsing the message with a template and generating at least one substring to be transmitted; parsing the at least one substring with entries in a session specific codebook and generating a first part of the compressed message; populating the session specific codebook with entries for unknown field values; parsing any unmatched substrings with entries from a first static dictionary and generating a second part of the compressed message; parsing any still unmatched substrings with entries from a second static dictionary and generating a third part of the compressed message; compressing a remainder of the substrings with a compression algorithm; and combining the first part, the second part, and the third part of the compressed message to obtain a compressed message for transmission.

Claims

1. A method of compressing a text message for transmission, comprising:

parsing text strings and encoding numerical values with a binary representation; and

analyzing values of the text strings and populating a session specific codebook with partial strings from the values.

2. The method of compressing a text message of claim 1, wherein the text strings include domain names and the domain names are replaced with IP addresses.

3. The method of compressing a text message of claim 2, wherein the IP addresses are encoded with binary representation.

4. The method of compressing a text message of claim 1, wherein the text message is parsed with a template.

5. The method of compressing a message of claim 4, wherein a different template is provided for each type of message.

6. The method of compressing a message of claim 4, wherein the template includes optional fields so that the template is usable for multiple message types.

7. The method of compressing a text message of claim 1, wherein the partial strings are parsed with entries in the session specific codebook.

8. The method of compressing a message of claim 1, wherein the session specific codebook is empty for the first text message compressed for transmission and entries are added as each message is compressed.

9. The method of compressing a message of claim 1, wherein the session specific codebook includes one or more entries for each header type.

10. The method of compressing a text message of claim 1, wherein the partial strings are parsed with a static dictionary.

11. The method of compressing a text message of claim 10, wherein the static dictionary is initialized with user specific information.

12. The method of compressing a text message of claim 10, wherein the static dictionary is initialized with past session history.

13. The method of compressing a text message of claim 1, wherein the partial strings not matched in the session specific codebook or the static dictionary are compressed with a compression algorithm.

14. The method of compressing a message of claim 13, wherein the compression algorithm is a Lempel-Ziv-based compression algorithm.

15. The method of compressing a message of claim 14, wherein the Lempel-Ziv-based compression algorithm is the Lempel-Ziv-Storer-Szymanski algorithm.

16. The method of compressing a message of claim 1, wherein the compressed message for transmission is an session initiation protocol (SIP), session description protocol (SDP), or realtime streamlining protocol (RTSP) message (RTSP).

17. A method of compressing a message for transmission, comprising:

parsing the message with a template and generating at least one substring to be transmitted;

parsing the at least one substring with entries in a session specific codebook and generating a first part of the compressed message;

populating the session specific codebook with entries for unknown field values;

parsing any unmatched substrings with entries from a first static dictionary and generating a second part of the compressed message;

parsing any still unmatched substrings with entries from a second static dictionary and generating a third part of the compressed message;

compressing a remainder of the substrings with a compression algorithm; and

combining the first part, the second part, and the third part of the compressed message to obtain a compressed message for transmission.

18. The method of compressing a message of claim 17, wherein a different template is provided is for each type of message.

19. The method of compressing a message of claim 17, wherein fields are added the template so that the template is usable for multiple message types.

20. The method of compressing a message of claim 17, wherein the session specific codebook is empty for the first compressed message and entries are added as each message is compressed.

21. The method of compressing a message of claim 17, wherein the one or more of the entries of the first static dictionary and the second static dictionary are binary encoded.

22. The method of compressing a message of claim 17, wherein the session specific codebook includes one or more entries for each header type.

23. The method of compressing a message of claim 17, wherein the first static dictionary and the second static dictionary include compression values previously encountered substrings.

24. The method of compressing a message of claim 17, wherein the first static dictionary and the second static dictionary are a single static dictionary.

25. The method of compressing a message of claim 17, wherein the compression algorithm is a Lempel-Ziv-type compression algorithm.

26. The method of compressing a message of claim 25, wherein the Lempel-Ziv-type compression algorithm is the Lempel-Ziv-Storer-Szymanski algorithm.

27. The method of compressing a message of claim 17, wherein the compressed message for transmission is an session initiation protocol (SIP), session description protocol (SDP), or realtime streamlining protocol (RTSP) message (RTSP).