Compression method, transmitter and receiver for radio data communication

• US 20040147247A1
• Filed: 07/16/2003
• Published: 07/29/2004
• Est. Priority Date: 02/07/2001
• Status: Abandoned Application

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Inventors: Demetrescu, Cristian, Sesmun, Amardiya, Foster, Gerry, Cheung, Colleen Yue Ling
• Application Number:
  US10/466,599
• Publication Number:
  US 20040147247A1
• Time in Patent Office: Days
• US Class Current: 455/412.1
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 67/561 Adding application-functional data or data for application control, e.g. adding metadata
• CPC Class Codes: H04L 67/5651 Reducing the amount or size of exchanged application data
• 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
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 4/12 Messaging; Mailboxes; Announcements
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 80/10 adapted for application session management, e.g. SIP [Session Initiation Protocol] connection management H04W76/00; arrangements for session management H04L67/14

Abstract

An SIP/SDP compression method, transmitter (510) and receiver (550) for communicating a message from the transmitter to the receiver by, at the transmitter, removing from the message element (s) thereof and inserting into the message an indication (200) of absence of the removed element (s); and, at the receiver, inserting into a message received from the transmitter element (s) pre-cached at the receiver in replacement for the element (s) whose absence is indicated. This provides a lightweight SIP/SPD compression scheme (LSSCS) that (i) removes the information redundancy generated at the application layer, and (ii) can achieve 100% compression efficiency for the redundant SIP and SDP URL fields.

Claims

1. A method of communicating a message from a transmitter to a receiver in a data communication system using Session Initiation Protocol and Session Description Protocol (SIP/SDP), the method comprising the steps of:

at the transmitter, removing from the message at least one element thereof and inserting into the message an indication of absence of the at least one removed element; and

at the receiver, inserting into a message received from the transmitter at least one element held at the receiver in replacement for the at least one element whose absence is indicated.

2. The method as claimed in claim 1 wherein the indication of absence comprises a binary header in which at least one bit indicates the presence/absence of the at least one element.

3. The method as claimed in claim 1 or 2 wherein the indication of absence further comprises an indication of whether a further indication of absence indicates the absence of at least one further element.

4. The method as claimed in claim 1, 2 or 3 further comprising the step of, before transmission of the message from the transmitter, pre-caching at the receiver at least one element of the message.

5. The method as claimed in any preceding claim further comprising the step of, before transmission of the message from the transmitter, receiving at the transmitter a predetermined table of mapping between elements of messages and indications of absence thereof.

6. The method as claimed in any preceding claim wherein the data communication system is a UMTS system.

7. A transmitter for use in communicating a message therefrom to a receiver in a data communication system using Session Initiation Protocol and Session Description Protocol (SIP/SDP), the transmitter comprising:

of;

means for removing from the message at least one element thereof; and

means for inserting into the message an indication of absence of the at least one removed element.

8. The transmitter as claimed in claim 7 wherein the indication of absence comprises a binary header in which at least one bit indicates the presence/absence of the at least one element.

9. The transmitter as claimed in claim 7 or 8 wherein the indication of absence further comprises an indication of whether a further indication of absence indicates the absence of at least one further element.

10. The transmitter as claimed in claim 7, 8 or 9 further comprising means for receiving, before transmission of the message therefrom, a predetermined table of mapping between elements of messages and indications of absence thereof.

11. The transmitter as claimed in any one of claims 7-10 wherein the data communication system is a UMTS system.

12. A receiver for receiving a message from a transmitter in a data communication system using Session Initiation Protocol and Session Description Protocol (SIP/SDP), the receiver comprising:

at the receiver, means for receiving from the transmitter a message including an indication of absence of at least one element from the received message; and

means for inserting into the received message at least one element held at the receiver in replacement for the at least one element whose absence is indicated.

13. The receiver as claimed in claim 12 wherein the indication of absence comprises a binary header in which at least one bit indicates the presence/absence of the at least one element.

14. The receiver as claimed in claim 12 or 13 wherein the indication of absence further comprises an indication of whether a further indication of absence indicates the absence of at least one further element.

15. The receiver as claimed in claim 12, 13 or 14 further comprising means for, before transmission of the message from the transmitter, pre-caching at the receiver at least one element of the message.

16. The receiver as claimed in any one of claims 12-15 further comprising means for sending to the transmitter, before transmission of the message therefrom, a predetermined table of mapping between elements of messages and indications of absence thereof.

17. The receiver as claimed in any one of claims 12-16 wherein the data communication system is a UMTS system.

18. A method of communicating a message from a transmitter to a receiver in a data communication system substantially as herein before described with reference to the accompanying drawings.

19. A transmitter for use in communicating a message therefrom to a receiver in a data communication system substantially as herein before described with reference to the accompanying drawings.

20. A receiver for receiving a message from a transmitter in a data communication system substantially as herein before described with reference to the accompanying drawings.