Real-Time Transport Protocol (RTP) Payload Format for the Variable-Rate Multimode Wideband (VMR-WB) Extension Audio Codec
RFC 4424

 
Document Type RFC - Proposed Standard (February 2006; No errata)
Updates RFC 4348
Last updated 2013-03-02
Replaces draft-ahmadi-avt-rtp-vmr-wb-extension
Stream IETF
Formats plain text pdf html
Stream WG state (None)
Consensus Unknown
Document shepherd No shepherd assigned
IESG IESG state RFC 4424 (Proposed Standard)
Telechat date
Responsible AD Allison Mankin
Send notices to csp@csperkins.org, magnus.westerlund@ericsson.com
Network Working Group                                          S. Ahmadi
Request for Comments: 4424                                 February 2006
Updates: 4348
Category: Standards Track

       Real-Time Transport Protocol (RTP) Payload Format for the
    Variable-Rate Multimode Wideband (VMR-WB) Extension Audio Codec

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   This document is an addendum to RFC 4348, which specifies the RTP
   payload format for the Variable-Rate Multimode Wideband (VMR-WB)
   speech codec.  This document specifies some updates in RFC 4348 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 4348.

   The payload formats and their associated parameters, as well as all
   provisions, restrictions, use cases, features, etc., that are
   specified in RFC 4348 are applicable to the new operating mode with
   no exception.

Table of Contents

   1. Introduction ....................................................2
   2. Conventions and Acronyms ........................................2
   3. The Variable-Rate Multimode Wideband (VMR-WB) Extension .........2
   4. The Necessary Updates in RFC 4348 ...............................4
   5. Security Considerations .........................................6
   6. Public Specification ............................................6
   7. IANA Considerations .............................................7
   8. References ......................................................7
      8.1. Normative References .......................................7
      8.2. Informative References .....................................7

Ahmadi                      Standards Track                     [Page 1]
RFC 4424          VMR-WB Extension RTP Payload Format      February 2006

1.  Introduction

   This document is an addendum to RFC 4348 [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 (VMR-WB mode
   4), although operating at a lower data rate, has similar
   characteristics and functionalities compared to the existing modes of
   VMR-WB already included in RFC 4348 (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 4348 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 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 4348 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 RFC 2119 [3].

   The following acronyms are used in this document:

      3GPP2  - Third Generation Partnership Project 2
      CDMA   - Code Division Multiple Access
      VMR-WB - Variable-Rate Multimode Wideband
      CMR    - Codec Mode Request
      DTX    - Discontinuous Transmission
      RTP    - Real-Time Transport Protocol
      MIME   - Multipurpose Internet Mail Extensions

3.  The Variable-Rate Multimode Wideband (VMR-WB) Extension

   VMR-WB is the wideband speech-coding standard developed by the 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 trade-off 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

Ahmadi                      Standards Track                     [Page 2]
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