Method and apparatus for communicating compression state information for interactive compression

• US 8,572,287 B2
• Filed: 02/14/2008
• Issued: 10/29/2013
• Est. Priority Date: 02/14/2008
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Ahmed, Salmaan, Sze, David P., Chan, Steven
• Primary Examiner(s): DOAN, DUYEN MY
• Application Number:
  US12/031,211
• Publication Number:
  US 20090210479A1
• Time in Patent Office: 2,084 Days
• Field of Search: 709/247, 455/72, 715/242, 707/101
• US Class Current: 709/247
• 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 comprising:

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

downloading, at a mobile device, compressed data from the server over a first connection;

determining, based on the side information identifier, if the unit of side information is resident on the mobile 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 over a second connection during the downloading of the compressed data over the first connection and receiving the unit of side information over the second connection during the downloading of the compressed data over the first connection.

2. The method according to claim 1, wherein the downloading of the compressed data is suspended until receipt of the unit of side information, if the unit of side information is not resident on the device.

3. The method according to claim 1 wherein the downloading of the compressed data is slowed 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 1, wherein the downloading of the compressed data is completed prior to requesting the unit of side information, if the unit of side information is not resident on the device.

5. 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.

6. 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.

7. The method according to claim 1, comprising transmitting a request for downloading the compressed data to the server prior to receiving the side information identifier.

8. 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 mobile device to transmit to a server a request for data;

to download from the server compressed data over a first connection;

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

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

if the unit of side information is resident on the mobile device, to load the side information for decompressing the compressed 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 over a second connection during the download of the compressed data over the first connection and to receive the unit of side information over the second connection during the download of the compressed data over the first connection.

9. A computer program product comprising a non-transitory 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, downloading compressed data from the server over a first connection, receiving, in response to the request, a side information identifier from the server for decompressing compressed data, determining if a unit of side information is resident on the 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 compressed data, otherwise if the unit of side information is not resident on the device, requesting the unit of side information from one of the server and another device over a second connection during the downloading of the compressed data over the first connection and receiving the unit of side information over the second connection during the downloading of the compressed data over the first connection.

10. 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;

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 over a first connection;

receiving, from the mobile device, a request for the unit of side information over a second connection during the transmitting of the compressed data over the first connection if the unit of side information associated with the unique side information identifier is not found on the mobile device; and

transmitting to the mobile device the unit of side information over the second connection, during transmitting the compressed data over the first connection, when the request for the unit of side information is received over the second connection.

11. The method according to claim 10, wherein receiving the unit of side information comprises receiving an update for the unit of side information.

12. The method according to claim 10, wherein computing the unique side information identifier comprises computing based on a byte length of the unit of side information and a hash of the unit of side information.

13. The method according to claim 10, wherein computing the unique side information 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.

14. The method according to claim 10, 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.

15. The method according to claim 10, comprising receiving a request for the data from the mobile device prior to selecting the unit of side information.