Audio Video Transport WG Sassan Ahmadi INTERNET-DRAFT Nokia Inc. Expires: December 7, 2005 June 7, 2005 Real-Time Transport Protocol (RTP) Payload Format for the Variable-Rate Multimode Wideband (VMR-WB) Extension Audio Codec Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html This document is a submission of the IETF AVT WG. Comments should be directed to the AVT WG mailing list, avt@ietf.org. Abstract This document is an addendum to RFC xxxx, which specifies the real-time transport protocol for the Variable-Rate Multimode Wideband (VMR-WB) speech codec. This document contains the information related to the new operating mode of VMR-WB. All provisions, restrictions, use cases, features, etc. that are specified in RFC xxxx are applicable to the new operating mode without any exception. No new media type registration is included in this document as the new VMR-WB mode, defined in this document, will use the same media type specified in RFC xxxx (i.e., audio/VMR-WB). Note that the RFC xxxx was developed with sufficient flexibility for future extensions and thereby it allows the addition of new operating modes without any impacts on the interoperability of terminals supporting different versions of the VMR-WB standard. Sassan Ahmadi [page 1] INTERNET-DRAFT VMR-WB Extension RTP Payload Format June 2005 Table of Contents 1.Introduction.................................................2 2.Conventions and Acronyms.....................................2 3.The Variable-Rate Multimode Wideband (VMR-WB) Extension......3 4.The Necessary Updates in RFC xxxx............................3 4.1. Implementation Considerations..........................5 5. Congestion Control..........................................5 6. Security Considerations.....................................5 6.1. Confidentiality........................................5 6.2. Authentication.........................................5 6.3. Decoding Validation and Provision for Lost or Late Packets................................................5 7. Payload Format Parameters...................................6 7.1. VMR-WB RTP Payload MIME Registration...................6 7.2. Mapping MIME Parameters into SDP.......................7 7.3. Offer-Answer Model Considerations......................7 8. IANA Considerations.........................................7 References.....................................................7 Normative References........................................7 Informative References......................................7 Author's Address...............................................7 IPR Notice.....................................................8 Copyright Notice...............................................8 1. Introduction This document is an addendum to RFC xxxx [2] and contains the necessary updates for the support of the new operating mode of 3GPP2 VMR-WB standard [1]. The new mode of VMR-WB standard (i.e., VMR-WB mode 4) has similar characteristics (e.g., narrowband/wideband input/output media processing capability, continuous and discontinuous transmission, etc.) as the other modes of VMR-WB already included in RFC xxxx. Therefore, all provisions and restrictions specified in RFC xxxx are applicable to all modes of the VMR-WB standard including the new mode, which is described in this document. As a result, no media type registration is required. The VMR-WB file format; i.e., for transport of VMR-WB speech data in storage mode applications, is specified in [1,4] and supports the new mode. The following sections provide the necessary updates to RFC xxxx to enable support of VMR-WB mode 4. 2. Conventions and Acronyms The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as Sassan Ahmadi [page 2] INTERNET-DRAFT VMR-WB Extension RTP Payload Format June 2005 described in RFC2119 [3]. The following acronyms are used in this document: 3GPP2 - The Third Generation Partnership Project 2 CDMA - Code Division Multiple Access VMR-WB - Variable-Rate Multimode Wideband Codec CMR - Codec Mode Request DTX - Discontinuous Transmission RTP - Real-Time Transport Protocol MIME - Multipurpose Internet Mail Extension SDP - Session Description Protocol The term "frame-block" is used in this document to describe the time-synchronized set of speech frames in a multi-channel 3. The Variable-Rate Multimode Wideband (VMR-WB) Extension VMR-WB is the wideband speech-coding standard developed by Third Generation Partnership Project 2 (3GPP2) for encoding/decoding wideband/narrowband speech content in multimedia services in 3G CDMA cellular systems [1]. VMR-WB is a source-controlled variable-rate multimode wideband speech codec. It has a number of operating modes, where each mode is a tradeoff between voice quality and average data rate. The operating mode in VMR-WB (as shown in Table 2) is chosen based on the traffic condition of the network and the desired quality of service. The desired average data rate (ADR) in each mode is obtained by encoding speech frames at permissible rates (as shown in Tables 1 and 3) compliant with CDMA2000 system depending on the instantaneous characteristics of input speech and the maximum and minimum rate constraints imposed by the network operator. The capabilities of the VMR-WB codec were extended through the addition of a new mode operating at lower average data rates, resulting in improved system capacity in IP and non-IP networks [1]. As a result of this extension, certain tables and parameters in RFC xxxx must be updated to support of the new operating mode. VMR-WB mode 4 is compliant with all applicable provisions and restrictions specified in RFC xxxx [2]. The existing flexibility in RFC xxxx for future extensions allows the addition of the new mode without any impact on the interoperability with earlier implementations of RFC xxxx. The following sections provide the necessary updates that are required to be made in RFC xxxx. 4. The Necessary Updates in RFC xxxx Sassan Ahmadi [page 3] INTERNET-DRAFT VMR-WB Extension RTP Payload Format June 2005 Table 1 of RFC xxxx is updated as follows: +---------------------------+-----------------+---------------+ | Frame Type | Bits per Packet | Encoding Rate | | | (Frame Size) | (kbps) | +---------------------------+-----------------+---------------+ | Full-Rate | 266 | 13.3 | | Full-Rate | 171 | 8.55 | | Half-Rate | 124 | 7.2 | | Half-Rate | 80 | 4.0 | | Quarter-Rate | 54 | 2.7 | | Quarter-Rate | 40 | 2.0 | | Eighth-Rate | 20 | 1.0 | | Eighth-Rate | 16 | 0.8 | | Blank | 0 | - | | Erasure | 0 | - | | Full-Rate with Bit Errors | 171 | 8.55 | +---------------------------+-----------------+---------------+ Table 1: CDMA2000 system permissible frame types and their associated encoding rates Note that the new permissible rates correspond to CDMA2000 rate-set I. Table 2 of RFC xxxx is updated as follows to include VMR-WB mode 4 and VMR-WB mode 4 with maximum half-rate similar to that described in Section 2.4 of the revised VMR-WB specification [1]. +-------+----------------------------------------------------------+ | CMR | VMR-WB Operating Modes | +-------+----------------------------------------------------------+ | 0 | VMR-WB mode 3 (AMR-WB interoperable mode at 6.60 kbps) | | 1 | VMR-WB mode 3 (AMR-WB interoperable mode at 8.85 kbps) | | 2 | VMR-WB mode 3 (AMR-WB interoperable mode at 12.65 kbps) | | 3 | VMR-WB mode 2 | | 4 | VMR-WB mode 1 | | 5 | VMR-WB mode 0 | | 6 | VMR-WB mode 2 with maximum half-rate encoding | | 7 | VMR-WB mode 4 | | 8 | VMR-WB mode 4 with maximum half-rate encoding | | 9-14 | (reserved) | | 15 | No Preference (no mode request is present) | +-------+----------------------------------------------------------+ Table 2: List of valid CMR values and their associated VMR-WB operating modes. Table 3 of RFC xxxx is updated as follows to include new frame types (FT) associated with VMR-WB mode 4. Note that the size of the frames are unique and different, allowing for the use of header-free payload format for all modes of operations [2]. Sassan Ahmadi [page 4] INTERNET-DRAFT VMR-WB Extension RTP Payload Format June 2005 +----+--------------------------------------------+-------------------+ | FT | Encoding Rate | Frame Size (Bits) | +----+--------------------------------------------+-------------------+ | 0 | Interoperable Full-Rate (AMR-WB 6.60 kbps) | 132 | | 1 | Interoperable Full-Rate (AMR-WB 8.85 kbps) | 177 | | 2 | Interoperable Full-Rate (AMR-WB 12.65 kbps)| 253 | | 3 | Full-Rate 13.3 kbps | 266 | | 4 | Half-Rate 6.2 kbps | 124 | | 5 | Quarter-Rate 2.7 kbps | 54 | | 6 | Eighth-Rate 1.0 kbps | 20 | | 7 | Full-Rate 8.55 kbps | 171 | | 8 | Half-Rate 4.0 kbps | 80 | | 9 | CNG (AMR-WB SID) | 35 | | 10 | Eighth-Rate 0.8 kbps | 16 | | 11 | (reserved) | - | | 12 | (reserved) | - | | 13 | (reserved) | - | | 14 | Erasure (AMR-WB SPEECH_LOST) | 0 | | 15 | Blank (AMR-WB NO_DATA) | 0 | +----+--------------------------------------------+-------------------+ Table 3:VMR-WB payload frame types for real-time transport Note that the new entires replace the "reserved" entries in RFC xxxx Tables 1 to 3 and there are no changes in the existing table entries of RFC xxxx. 4.1 Implementation Considerations Same as RFC xxxx 5. Congestion Control Same as RFC xxxx 6. Security Considerations Same as RFC xxxx 6.1. Confidentiality Same as RFC xxxx 6.2. Authentication Same as RFC xxxx 6.3. Decoding Validation and Provision for Lost or Late Packets Sassan Ahmadi [page 5] INTERNET-DRAFT VMR-WB Extension RTP Payload Format June 2005 Same as RFC xxxx 7. Payload Format Parameters Same as RFC xxxx. 7.1. VMR-WB RTP Payload MIME Registration No MIME registration is required for the new mode of VMR-WB. The only necessary update is in the definition of the optional MIME parameter "mode-set" by adding the new operating mode. Note that the addition of the new mode does not create any interoperability issues since the modes of operation are negotiated and agreed by the IP terminals through the offer-answer model provided in Section 9.3 of RFC xxxx [2]. mode-set: Requested VMR-WB operating mode set. Restricts the active operating modes to a subset of all modes. Possible values are a comma separated list of integer values. Currently, this list includes modes 0,1,2, 3, and 4 [1,2] but MAY be extended in the future. If such mode-set is specified during session initiation, the encoder MUST NOT use modes outside of the subset. If not present, all operating modes in the set 0 to 4 are allowed for the session. Encoding considerations: Same as RFC xxxx Security considerations: Same as RFC xxxx Public specification: The VMR-WB speech codec is specified in following 3GPP2 specifications C.S0052-A version 1.0. Transfer methods are specified in RFC xxxx. Additional information: Person & email address to contact for further information: Sassan Ahmadi, Ph.D. Nokia Inc. USA sassan.ahmadi@nokia.com Intended usage: COMMON. Same as RFC xxxx Sassan Ahmadi [page 6] INTERNET-DRAFT VMR-WB Extension RTP Payload Format June 2005 Author/Change controller: IETF Audio/Video Transport working group delegated from the IESG 7.2. Mapping MIME Parameters into SDP Same as RFC xxxx 7.3. Offer-Answer Model Considerations Same as RFC xxxx 8. IANA Considerations None References Normative References [1] 3GPP2 C.S0052-A v1.0 "Source-Controlled Variable-Rate Multimode Wideband Speech Codec (VMR-WB) Service Options 62 and 63 for Spread Spectrum Systems", 3GPP2 Technical Specification, April 2005. [2] S. Ahmadi, "Real-Time Transport Protocol (RTP) Payload Formats for the Variable-Rate Multimode Wideband (VMR-WB) Audio Codec", RFC xxxx, Internet Engineering Task Force, May 2005. [3] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, Internet Engineering Task Force, March 1997. Informative References [4] 3GPP2 C.S0050-A v1.0 "3GPP2 File Formats for Multimedia Services", 3GPP2 Technical Specification, May 2005. Any 3GPP2 document can be downloaded from the 3GPP2 web server, "http://www.3gpp2.org/", see specifications. Author's Address The editor will serve as the point of contact for all technical matters related to this document. Dr. Sassan Ahmadi Phone: 1 (858) 831-5916 Fax: 1 (858) 831-5111 Sassan Ahmadi [page 7] INTERNET-DRAFT VMR-WB Extension RTP Payload Format June 2005 Nokia Inc. Email: sassan.ahmadi@nokia.com 12278 Scripps Summit Dr. San Diego, CA 92131 USA This Internet-Draft expires in six months from June 7, 2005. RFC Editor Considerations The RFC editor is requested to replace all occurrences of xxxx with the RFC number that reference [2] will receive. IPR Notice The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Copyright Notice Copyright (C) The Internet Society (2005). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Sassan Ahmadi [page 8]