Internet DRAFT - draft-ietf-avt-rtp-vmr-wb-extension
draft-ietf-avt-rtp-vmr-wb-extension
Audio Video Transport WG Sassan Ahmadi
INTERNET-DRAFT
Expires: April 19, 2006 October 19, 2005
Real-Time Transport Protocol (RTP) Payload Format for the
Variable-Rate Multimode Wideband (VMR-WB) Extension Audio Codec
<draft-ietf-avt-rtp-vmr-wb-extension-02.txt>
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
RTP payload format for the Variable-Rate Multimode Wideband (VMR-WB)
speech codec. This document specifies some updates in RFC xxxx to
enable support for the new operating mode of VMR-WB standard (i.e.,
VMR-WB mode 4). These updates do not affect the existing modes of
VMR-WB already specified in RFC xxxx.
The payload formats and their associated parameters, as well as all
provisions, restrictions, use cases, features, etc. that are
specified in RFC xxxx are applicable to the new operating mode with
no exception.
Sassan Ahmadi Standards Track [page 1]
INTERNET-DRAFT VMR-WB Extension RTP Payload Format October 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
5.Security Considerations......................................5
6.Public Specification.........................................5
7.IANA Considerations..........................................5
References.....................................................5
Normative References........................................5
Informative References......................................6
Author's Address...............................................6
IPR Notice.....................................................6
Copyright Notice...............................................7
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, while operating at a lower data rate, has similar
characteristics and functionalities compared to the existing modes
of VMR-WB already included in RFC xxxx (e.g., variable bit rate,
narrowband/wideband input/output speech/audio processing capability,
continuous and discontinuous transmission, etc.). 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
specified in this document. As a result, no new 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 includes
support for the new mode of operation.
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 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
Sassan Ahmadi Standards Track [page 2]
INTERNET-DRAFT VMR-WB Extension RTP Payload Format October 2005
RTP - Real-Time Transport Protocol
MIME - Multipurpose Internet Mail Extension
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 reserved table entries in
RFC xxxx are used to include support for the new operating mode.
VMR-WB mode 4 is compliant with all applicable provisions and
restrictions specified in RFC xxxx [2]. Note that the existing table
entries of RFC xxxx remain unchanged (e.g., frame types, etc.) and
the original modes of VMR-WB are not affected by these updates.
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.
The provisions and considerations for implementation, congestion
control, and security remain identical to those specified in
RFC xxxx.
4. The Necessary Updates in RFC xxxx
Table 1 of RFC xxxx is updated as follows:
Sassan Ahmadi Standards Track [page 3]
INTERNET-DRAFT VMR-WB Extension RTP Payload Format October 2005
+---------------------------+-----------------+---------------+
| 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 have been added to the table.
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.
Note that CMR values 7 and 8 replace the reserved values in Table 2
of RFC xxxx.
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 Standards Track [page 4]
INTERNET-DRAFT VMR-WB Extension RTP Payload Format October 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 FT types associated with VMR-WB mode 4 replace the
reserved entries 7, 8, and 10 in Table 3 of RFC xxxx and there are
no changes in the existing entries of Table 3 of RFC xxxx.
The 'mode-set' MIME parameter value 4 is defined to indicate that
VMR-WB mode 4 is supported and used. Note that the active 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].
5. Security Considerations
Same as RFC xxxx
6. Public specification
The VMR-WB speech codec including the new mode is specified in
following 3GPP2 specification C.S0052-A version 1.0. Transfer
methods are specified in RFC xxxx.
7. IANA Considerations
None
References
Normative References
Sassan Ahmadi Standards Track [page 5]
INTERNET-DRAFT VMR-WB Extension RTP Payload Format October 2005
[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, October 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, October 2005.
Any 3GPP2 document can be downloaded from the 3GPP2 web
server, "http://www.3gpp2.org/", see specifications.
Author's Address
Dr. Sassan Ahmadi Email: sassan.ahmadi@ieee.org
This Internet-Draft expires in six months from October 19, 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
Sassan Ahmadi Standards Track [page 6]
INTERNET-DRAFT VMR-WB Extension RTP Payload Format October 2005
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 Standards Track [page 7]
