METHOD AND APPARATUS FOR COMMUNICATING COMPRESSION STATE INFORMATION FOR INTERACTIVE COMPRESSION

• US 20090210479A1
• Filed: 02/14/2008
• Published: 08/20/2009
• Est. Priority Date: 02/14/2008
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: SlipStream Data Incorporated (Blackberry Limited)
• Inventors: AHMED, Salmaan, SZE, David P., CHAN, Steven
• Granted Patent: US 8,572,287 B2
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC

Abstract

A method of determining, at a mobile device, side information including compression state information. The method includes receiving, from a server, a unique side information identifier identifying a unit of side information used by the server for compressing data, determining, based on the side information identifier, if the unit of side information is resident on said device, and if the unit of side information is resident on the mobile device, loading the side information for decompressing the data. Otherwise, if the unit of side information is not resident on the mobile device, the method includes requesting the unit of side information from one of the server and another device.

Claims

1. A method of determining, at a mobile device, side information including compression state information, the method comprising:

receiving, from a server, a unique side information identifier identifying a unit of side information used by the server for compressing data;

determining, based on the side information identifier, if the unit of side information is resident on said device; and

if the unit of side information is resident on the mobile device, loading the side information for decompressing the data;

otherwise

if the unit of side information is not resident on the mobile device, requesting the unit of side information from one of the server and another device.

2. The method according to claim 1, comprising downloading the data compressed by the server.

3. The method according to claim 2, wherein said downloading is suspended until receipt of the unit of side information, if the unit of side information is not resident on the device.

4. The method according to claim 2, wherein said downloading is slowed until receipt of the unit of side information, if the unit of side information is not resident on the device.

5. The method according to claim 2, wherein said downloading is completed prior to requesting the unit of side information, if the unit of side information is not resident on the device.

6. The method according to claim 5, comprising caching the data from the server prior to requesting the unit of side information.

7. The method according to claim 1, comprising downloading the data from the server and receiving said unit of side information in response to requesting the unit of side information.

8. The method according to claim 1, wherein receiving the side information identifier comprises receiving a byte length of the unit of side information and a hash of the bytes of the unit of side information.

9. The method according to claim 1, comprising, in response to said requesting, receiving the unit of side information and caching the unit of side information.

10. The method according to claim 1, comprising transmitting a request for said data to said server prior to receiving said side information identifier.

11. A mobile device comprising:

a housing;

a display device exposed by the housing;

an input device;

a memory unit within the housing; and

a processor within the housing and operably connected to the display device, the input device and the memory unit for executing a program stored in the memory unit to cause the electronic device to transmit to a server a request for data;

to download from the server the data;

to receive from the server, in response to said request, a unique side information identifier for decompressing the data downloaded;

to determine if a unit of side information identified by the side information identifier is resident on said device; and

if the unit of side information is resident on the device, to load the side information for decompressing the data;

otherwise if the unit of side information is not resident on the mobile device, to request the unit of side information from one of the server and another device.

12. A computer program product comprising a computer-readable medium having computer-readable code embodied therein for execution by a processor of a portable electronic device for transmitting a request for data to a server, receiving, in response to said request, a side information identifier from the server for decompressing the data downloaded, determining if a unit of side information is resident on said device based on the side information identifier, and if the unit of side information is resident on the device, loading the side information for decompressing the data, otherwise if the unit of side information is not resident on the mobile device, requesting the unit of side information from one of the server and another device.

13. A server method of sharing side information for compression and decompression of data, the method comprising:

receiving a unit of side information for use in compressing data for transmission to a mobile device;

computing a unique side information identifier;

transmitting the unique side information identifier to the mobile device, wherein said unit of side information is transmitted to the mobile device along with the unique identifier or said unit of side information is transmitted to the mobile device in response to a request from the mobile device.

14. The method according to claim 13, wherein receiving the unit of side information comprises receiving an update for the unit of side information.

15. The method according to claim 13, wherein computing the unique identifier comprises computing based on a byte length of the unit of side information and a hash of the unit of side information.

16. The method according to claim 13, wherein computing the unique identifier comprises computing based on at least one of a byte length of the unit of side information, a hash of the unit of side information, a modification date and time of the unit of side information, a version number of the unit of side information, and a randomly generated number.

17. The method according to claim 13, comprising:

selecting the unit of side information for compressing the data for sending to a mobile device;

compressing the data using the unit of side information; and

transmitting to the mobile device the compressed data and the side information identifier for identifying the unit of side information for decompression of the compressed data.

18. The method according to claim 17, wherein selecting the unit of side information comprises selecting the unit of side information based on at least one of a user name and a user group.

19. The method according to claim 17, comprising receiving a request for the data from the mobile device prior to selecting the unit of side information.

20. The method according to claim 17, comprising receiving from the mobile device, a request for the unit of side information if the unit of side information associated with the unique side information identifier is not found on the mobile device.