System and method for compressing data on a bandwidth-limited network

• US 20030006919A1
• Filed: 07/09/2001
• Published: 01/09/2003
• Est. Priority Date: 07/09/2001
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Good Technology Incorporated (Blackberry Limited)
• Inventors: Collins, Roger, Friend, John Lawrence
• Granted Patent: US 7,064,688 B2
• Time in Patent Office: Days
• US Class Current: 341/87
• CPC Class Codes: H03M 7/30 Compression speech analysis-synthesis for redundancy reduction G10L19/00; for image communication H04N; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
• CPC Class Codes: H03M 7/3084 using adaptive string matching, e.g. the Lempel-Ziv method
• CPC Class Codes: H03M 7/40 Conversion to or from variable length codes, e.g. Shannon-Fano code, Huffman code, Morse code
• CPC Class Codes: H03M 7/42 using table look-up for the coding or decoding process, e.g. using read-only memory H03M7/4006 takes precedence
• CPC Class Codes: H04L 51/00 User-to-user messaging in packet-switching networks, transmitted according to store-and-forward or real-time protocols, e.g. e-mail
• CPC Class Codes: H04L 51/063 Content adaptation, e.g. replacement of unsuitable content
• CPC Class Codes: H04L 51/066 Format adaptation, e.g. format conversion or compression
• CPC Class Codes: H04L 51/58 Message adaptation for wireless communication
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC

Abstract

A method for compressing a message is disclosed, comprising: identifying a block of data within the message which is found in a previous message; generating a pointer identifying the block of data in said previous message; and replacing the block of data with the pointer in the message.

Claims

1. A method for compressing a message comprising:

identifying a block of data within said message which is found in a previous message;

generating a pointer identifying said block of data in said previous message; and

replacing said block of data in said message with said pointer.

2. The method as in claim 1 further comprising:

transmitting said message to a data processing device, said data processing device having said previous message stored thereon.

3. The method as in claim 2 further comprising:

decompressing said message by inserting said block of data from said previous message into said message.

4. The method as in claim 1 further comprising:

identifying said previous message based on characters in said message'"'"'s subject field.

5. The method as in claim 4 wherein said characters include text indicating that said message is a response to said previous message.

6. The method as in claim 1 further comprising:

compressing said message further using one or more alternate compression techniques.

7. The method as in claim 6 wherein one of said alternate compression techniques comprises:

replacing common strings of characters with one or more code words.

8. The method as in claim 7 wherein one of said strings of characters is an email address domain.

9. The method as in claim 1 further comprising:

encoding portions of text in said message not in said block of data using 6-bits per character.

10. The method as in claim 1 wherein said message is an email message.

11. A system for compressing messages comprising:

message identification logic for identifying a previous message which contains a block of data found in a new message;

state-based compression logic for compressing said message by replacing said block of data with a pointer identifying said block of data in said previous message.

12. The system as in claim 11 further comprising:

transmission logic for transmitting said message to a data processing device, said data processing device having said previous message stored thereon.

13. The system as in claim 12 further comprising:

decompression logic to decompress said message on said wireless data processing device by inserting said block of data from said previous message into said message.

14. The system as in claim 11 wherein said message identification logic identifies said previous message based on characters in said message'"'"'s subject field.

15. The system as in claim 14 wherein said characters include text indicating that said message is a response to said previous message.

16. The system as in claim 11 further comprising:

one or more alternate compression modules for compressing said message further using one or more alternate compression techniques.

17. The system as in claim 16 wherein one of said alternate compression modules comprises:

a code word generation module which replaces common strings of characters with one or more code words.

18. The system as in claim 17 wherein one of said strings of characters is an email address domain.

19. The system as in claim 16 wherein one of said alternate compression modules comprises a 6-bit text encoding module to encode portions of text in said message not in said block of data using 6-bits per character.

20. The system as in claim 11 wherein said message is an email message.

21. A method comprising:

providing an interface to a message service, said interface compressing messages and forwarding said compressed messages to a data processing device,

wherein said interface compresses a message by searching for prior messages transmitted to or received from said data processing device which contain a block of data found in said message and replacing said block of data with a pointer to said block of data in said prior messages.

22. The method as in claim 21 wherein said message is an email message.

23. The method as in claim 21 further comprising:

transmitting said message to a data processing device, said data processing device having said previous message stored.

24. The method as in claim 22 further comprising:

decompressing said message at said data processing device by inserting said block of data from said previous message into said message.

25. The method as in claim 21 wherein said interface identifies said previous message based on characters in said message'"'"'s subject field.

26. The method as in claim 25 wherein said characters include text indicating that said message is a response to said previous message.

27. The method as in claim 21 wherein said interface further compresses said message further using one or more alternate compression techniques.

28. The method as in claim 27 wherein one of said alternate compression techniques comprises:

replacing common strings of characters with one or more code words.

29. The method as in claim 28 wherein one of said strings of characters is an email address domain.

30. The method as in claim 21 wherein said interface further compresses said message by encoding portions of text in said message not in said block of data using 6-bits per character.