1. 1 0-Byte Header Reduction Mechanism Fundamentals

2. 2 Presentation Summary Objectives and Recommendation Why New Header Compression? Header Compression Functional View MAC Layer Functional View Header Reduction Scheme, End-to-End Model Header Reduction Scheme, Stripping and Regeneration Model Header Reduction Scheme, Hybrid Model Conclusion

3. 3 Objectives and Recommendation Introduce the VOIP Header Reduction schemes selected by TSGP as a means to highlight: The expected impacts to the MAC sublayer as a result of introducing these schemes. Some of these impacts include: ŒNew Service Options ŒNew type of RLP ŒMAC Layer Assisted Header Reduction Mechanism Recommendation: review and discuss in WG1

4. 4 Why New Header Compression? For limited bandwidth links the extra overhead is unrealistic and unacceptable Existing compression schemes (e.g. IETF RFC 2508) perform poorly when face with high error rates and long delays typically seen in the cellular radio environment Œpoor performance at high error rates (10 -3 BER) or when delay is long (200 mS) Œerror propagation (one bad packet can cause loss of next 'N' good ones) IP header (20 in v4, 40 in v6)UDP header (8)RTP header (12)Payload (~20 to 30) Slide based onNokia contribution “ C12-20010326-008-NOKIA - RTP Header Compression using ROHC” with some modifications

5. 5 Speech sample Header Compression: Functional Diagram Header Compressor Airlink Header Decompressor IP UDP RTP IPUDPRTP Speech sample Air interface Speech Application Speech Application Speech sample CH IP/UDP/RTP Header Reproduced Exactly Functionality Supported above Link Layer between IP and PPP Slide based onNokia contribution “ C12-20010326-008-NOKIA - RTP Header Compression using ROHC” with some modifications

6. 6 Speech sample 3GPP2 Header Reduction: Network Functional Diagram Header Compressor Airlink Header Decompressor IP UDP RTP IPUDPRTP Speech sample Air interface Speech Application Speech Application Speech sample IP/UDP/RTP Header Reproduced Exactly Functionality Supported above Link Layer between IP and PPP Header Reduction Functions Slide based onNokia contribution “ C12-20010326-008-NOKIA - RTP Header Compression using ROHC” with some modifications

7. 7 Proposed Header size reduction mechanisms in TSG-P (Model 2) Hybrid Model (IP is terminated before the cellular link) Initial Context Update on Forward Direction Only Context is initialized out of band through PPP IP is terminated at the PDSN RLFRLF R - Received packet L - Packet over link F - Forwarded packet (Model 3) End-to-End Model Context is initialized and updated on both direction as needed (fully or partially) Context updates take place in band IP is transparently supported end-to-end Header are decompressed based on last context update RLFRLF (Model 4) Header Stripping Model Initial Context Update on Forward and Reverse Direction Context is always updated in full (out of band through PPP) when required Header are regenerated based on initial context update RLFRLF - Header - Payload - Compressed Header - Regenerated Header

8. 8 End-to-End Model 3GPP2 Header Reduction : MAC Functional Diagram (Forward Direction) GRE Layer Link Layer Assisted ROHC Profile ROHC Header Information GRE PHYL Packet Available Send last received Context Check Packet MACSublayer PHYL Frame Error Generate missing/ bad Frame Indication MAC Sublayer YES NO YES NO Link Layer Assisted ROHC Profile Speech sample IP UDP RTP IP UDP RTP Store received CCP NewRadioLinkInstance New Radio Link Instance PPP NetworkSideMSSide Speech sample ROHC Header Information ROHC Header Speech sample

9. 9 GRE Layer Link Layer Assisted ROHC Profile GRE PHYL Packet Available Send last received Context Check Packet MACSublayer PHYL Frame Error Generate missing/ bad Frame Indication MAC Sublayer YES NO YES NO Link Layer Assisted ROHC Profile Speech sample IP UDP RTP IP UDP RTP Store received CCP End-to-End Model 3GPP2 Header Reduction : MAC Functional Diagram (Reverse Direction) NewRadioLinkInstance New Radio Link Instance PPP MSSideNetworkSide ROHC Header Speech Sample ROHC Header Information Speech sample

10. 10 Header Stripping and Regeneration 3GPP2 Header Reduction : MAC Functional Diagram (Forward Direction) GRE Layer Header Stripping Function PHYL Packet Available Send Blank Data Frame (As today) MACSublayer PHYL Frame Error Send Blank Data Frame (As today) MAC Sublayer NO YES NO Speech Sample Header Regeneration Function Speech sample IP UDP RTP IP UDP RTP YES NewRadioLinkInstance New Radio Link Instance Context Update through MCFTP Context Update through MCFTP GRE Speech Sample/ Context Update PPP NetworkSideMSSide Speech sample

11. 11 GRE Layer Header Stripping Function Speech sample GRE PHYL Packet Available Send Blank Data Frame (As today) MACSublayer PHYL Frame Error Send Blank Data Frame (As today) MAC Sublayer YES NO YES NO Speech Sample/ Context Update Speech sample IP UDP RTP IP UDP RTP Header Stripping and Regeneration 3GPP2 Header Reduction : MAC Functional Diagram (Reverse Direction) NewRadioLinkInstance New Radio Link Instance Context Update through MCFTP Context Update through MCFTP Header Regeneration Function MSSideNetworkSide PPP

12. 12 Header Removal 3GPP2 Header Reduction : MAC Functional Diagram (Forward Direction) GRE Layer Link Layer Assisted ROHC Profile + Header Removal Functions Speech sample GRE PHYL Packet Available Send Blank Data Frame (As today) MACSublayer PHYL NO Speech Sample Speech Application Speech sample IP UDP RTP YES NewRadioLinkInstance Frame Error Generate missing/ bad Frame Indication MAC Sublayer YES NO New Radio Link Instance PPP Link Layer Assisted ROHC Lite PPP NetworkSideMSSide

13. 13 GRE Layer Speech Application Speech sample GRE PHYL Packet Available Send Blank Data Frame (As today) MACSublayer YES NO Speech Sample/Context Initialization Link Layer Assisted ROHC Profile Speech sample IP UDP RTP Header Removal 3GPP2 Header Reduction : MAC Functional Diagram (Reverse Direction) NewRadioLinkInstance Frame Error Generate missing/ bad Frame Indication MAC Sublayer YES NO New Radio Link Instance PHYL Link Layer Assisted ROHC Lite PPP MSSideNetworkSide

14. 14 Conclusion 0-Byte Header Reduction is possible and it can be achieved using characteristics of a synchronous radio link layer such as CDMA 2000 radio link layer. A new service option is needed in order to request a VoIP service using a particular Header Reduction Model A new frame free, non-re-transmitting Radio Link Instance is required New header functionality is required at the MAC sublayer in order to handle Header Reduction directives