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

• US 7,064,688 B2
• Filed: 07/09/2001
• Issued: 06/20/2006
• Est. Priority Date: 07/09/2001
• Status: Expired due to Term

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Good Technology Incorporated (Blackberry Limited)
• Inventors: Friend, John Lawrence, Collins, Roger
• Primary Examiner(s): WAMSLEY, PATRICK G
• Application Number:
  US09/902,060
• Publication Number:
  US 20030006919A1
• Time in Patent Office: 1,807 Days
• Field of Search: 341/87, 341/50, 341/51, 341/95, 341/106, 709/206, 709/204, 709/315, 235/431, 711/170, 711/201, 707/104.1, 707/10, 379/100.08, 379/93.24
• 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 an electronic message comprising:

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

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

replacing said block of data in said electronic message with said pointer; and

transmitting said electronic mail message to a wireless data processing device having said previous electronic mail message stored thereon.

2. The method as in claim 1 further comprising:

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

3. The method as in claim 2 wherein one of said alternate compression techniques comprises:

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

4. The method as in claim 3 wherein one of said strings of characters is an electronic mail (email) address domain.

5. The method as in claim 1 further comprising:

identifying said previous electronic mail message based on characters in a subject field of said message.

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

7. The method as in claim 5 further comprising:

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

8. The method as in claim 1 further comprising:

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

9. A system comprising:

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

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

transmission logic for transmitting said new electronic mail message to a wireless data processing device having said previous electronic mail message stored thereon.

10. The system as in claim 9 further comprising:

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

11. The system as in claim 10 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.

12. The system as in claim 11 wherein one of said strings of characters is an electronic mail (email) address domain.

13. The system as in claim 10 wherein one of said alternate compression modules comprises a 6-bit text encoding module to encode portions of text in said new electronic message not in said block of data using 6-bits per character.

14. The system as in claim 9 wherein said message identification logic identifies said previous electronic mail message based on characters in a subject field of said new electronic mail message.

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

16. The system as in claim 9 further comprising:

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

17. 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 an electronic message by searching for prior electronic messages transmitted to or received from said data processing device which include a block of data found in said electronic message and replacing said block of data with a pointer to said block of data in said prior electronic mail messages; and

transmitting said electronic mail message to a wireless to a wireless data processing device having previous electronic mail message stored.

18. The method as in claim 17 wherein said interface further compresses said electronic mail message further using one or more alternate compression techniques.

19. The method as in claim 18 wherein one of said alternate compression techniques comprises:

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

20. The method as in claim 19 wherein one of said strings of characters is an electronic mail (email) address domain.

21. The method as in claim 17 wherein said interface identifies said previous electronic mail message based on characters in a subject message of said electronic mail message.

22. The system as in claim 21 wherein said characters include text indicating that said electronic mail message is a response to said previous electronic message.

23. The method as in claim 17 further comprising:

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

24. The method as in claim 17 wherein said interface further compresses said electronic message by encoding portions of text in said electronic message not in said block of data using 6-bits per character.