[Docs] [txt|pdf] [Tracker] [Email] [Nits]

Versions: 00

INTERNET-DRAFT                         Laile L. Di Silvestro (Microsoft)
Expires in 6 months                             Erik Hedberg (Microsoft)
                                              Greg Baribault (Microsoft)
                                                   Microsoft Corporation
                                                           April 1, 1999

                   Toll Quality Voice - Microsoft GSM
                       MIME Sub-type Registration
                      <draft-ema-vpim-msgsm-00.txt>


Status of this memo:

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

   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/ietf/1id-abstracts.txt

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This draft is being discussed by the Electronic Messaging
   Association VPIM work group. To subscribe to the mailing list, send
   a message to EMA Listserv Requests [listserv@listmail.ema.org] with
   the line "subscribe VPIM-L" in the body of the message.



















Di Silvestro, Hedberg, Baribault        Expires 10/1/99         [Page 1]


Internet Draft                audio/ms-gsm                        4/1/99



Abstract

   This document describes the registration of the MIME sub-type
   audio/ms-gsm for toll quality audio.  This audio encoding is defined
   by the European Telecommunications Standards Institute (ETSI) in
   ETS 300 961.

1. Introduction

   The MIME subtype "ms-gsm" is being defined primarily for use in
   multimedia and voice messaging standards.  The Voice Profile for
   Internet Messaging, version 3 [VPIM3] working draft specifies that
   all VPIM version 3 compliant implementations MAY generate
   audio/ms-gsm bodyparts and MUST receive audio/ms-gsm bodyparts.

   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 [REQ].

2. ETSI Definition

   ETS 300 961 (GSM 06.10 version 5.1.1) [GSM] was prepared by
   European Telecommunications Standards Institute (ETSI) in May 1998.
   It is a reproduction of recommendation T/L/03/11 "13kbit/s
   Regular Pulse Excitation - Long Term Prediction - Linear Predictive
   Coder for use in the digital cellular telecommunications system."

   ETS 300 961 describes the detailed mapping between input blocks of
   160 speech samples in 13 bit uniform PCM format to encoded blocks of
   260 bits, and from encoded blocks of 260 bits to output blocks of
   160 reconstructed speech samples.  The sampling rate is
   8000 sample/s leading to an average bit rate for the encoded bit
   stream of 13 kbit/s.  The coding scheme is the so-called Regular
   Pulse Excitation - Long Term prediction - Linear Predictive
   Coder, here-after referred to as RPE-LTP.

2.1 Parameter storage

   ETS 300 961 provides a detailed description of the mapping of blocks
   of 160 speech samples in 13 bit uniform PCM format to 76 encoder
   parameters, and the mapping from those encoder parameters back to
   160 reconstructed speech samples.  The 76 encoder parameters vary in
   width from 2 to 7 bits, so they all fit in 260 bits.

   ETS 300 961 does not define the correct way to store these 76
   parameters in a computer file, however. To promote interoperability,
   this document describes the MS-GSM version of GSM 06.10 which is to
   be used to encode audio/ms-gsm data.




Di Silvestro, Hedberg, Baribault        Expires 10/1/99         [Page 2]


Internet Draft                audio/ms-gsm                        4/1/99

   Audio/ms-gsm implementations MUST pack two sets of encoder output
   parameters into 65 bytes and MUST right justify the parameters in
   a byte.  Since each set of encoder output parameters occupies 32.5
   bytes, the two sets will be offset by a nibble (4 bits).

   In this illustration, as in ETS 300 961, arrays are 1-based and
   the least significant bit is numbered 1.
   The first eight encoder parameters are named LAR1 through LAR8,
   and they vary from 6 to 3 bits in width. The notation LAR1[6-3]
   indicates the 4 high order bits of LAR1, and LAR5[2-1] indicates
   the 2 low-order bits of LAR5. The remaining 68 parameters are
   packed similarly.


     MSB                                                       LSB
     Bit 8   Bit 7   Bit 6   Bit 5   Bit 4   Bit 3   Bit 2   Bit 1
   +-------+-------+-------+-------+-------+-------+-------+-------+
   |   LAR2[2-1]   |                   LAR1[6-1]                   |
   +-------+-------+-------+-------+-------+-------+-------+-------+
   |           LAR3[4-1]           |          LAR2[6-3]            |
   +-------+-------+-------+-------+-------+-------+-------+-------+
   |  LAR5[2-1]    |                LAR4[5-1]              |LAR3[5]|
   +-------+-------+-------+-------+-------+-------+-------+-------+
   |  LAR7[2-1]    |           LAR6[4-1]           |   LAR5[4-3]   |
   +-------+-------+-------+-------+-------+-------+-------+-------+
                                   |        LAR8[3-1]      |LAR7[3]|
                                   +-------+-------+-------+-------+


3.   MIME Definition

3.1  audio/ms-gsm

   European Telecommunications Standards Institute (ETSI) ETS 300
   961 [GSM] describes the algorithm recommended for conversion of
   blocks of 160 speech samples in 13 bit uniform PCM format to
   encoded blocks of 260 bits, and the mapping back from those 260
   bit blocks to output blocks of 160 reconstructed speech
   samples.

   The MIME sub-type audio/ms-gsm is defined to hold binary audio
   data encoded exactly as defined by ETS 300 961 (GSM 06.10) No
   header information shall be included as part of the audio data.
   The content transfer encoding is typically either binary or
   base64.

   To enable interoperability, the audio data MUST conform to the
   parameter storage definition provided in the section above and
   in the IANA registration below.





Di Silvestro, Hedberg, Baribault        Expires 10/1/99         [Page 3]


Internet Draft                audio/ms-gsm                        4/1/99


3.2 VPIM Usage

   The audio/ms-gsm sub-type is a component of the proposed VPIM
   version 3 specification [VPIM3]. In this context, the
   Content-Description headers is used to succinctly describe
   the contents of the audio body.

   All VPIM Version 3 systems MUST be capable of receiving audio
   encoded in the MS-GSM version of GSM 06.10. Sending systems MAY
   choose to send audio data encoded in MS-GSM. All receiving
   systems MUST be able to process MS-GSM audio data.

   Refer to the VPIM Specification for proper usage.

4. IANA Registration

   To: ietf-types@iana.org
   Subject: Registration of MIME media type audio/ms-gsm

   MIME media type name: audio

   MIME subtype name: ms-gsm

   Required parameters: none

   Optional parameters: none

   Encoding considerations:
      Binary or Base-64 generally preferred

   Security considerations:
      There are no known security risks with the sending or
      playing of raw audio data.  Audio data is typically interpreted
      only by an audio codec.  Unintended information introduced into
      the data stream will result in noise.

   Interoperability considerations:
      MS-GSM is not compatible with other GSM 06.10
      implementations.  To be interoperable, Audio/ms-gsm
      implementations MUST pack two encoder parameter blocks into 65
      bytes and MUST right justify the parameters in a byte.












Di Silvestro, Hedberg, Baribault        Expires 10/1/99         [Page 4]


Internet Draft                audio/ms-gsm                        4/1/99


      In this illustration, as in ETS 300 961, arrays are 1-based
      and the least significant bit is numbered 1. The first 8
      encoder parameters are named LAR1 through LAR8, and they vary
      from 6 to 3 bits in width. The notation LAR1[6-3] indicates
      the 4 high order bits of LAR1, and LAR5[2-1] indicates the 2
      low-order bits of LAR5. The remaining 68 parameters are
      packed similarly.

     MSB                                                       LSB
     Bit 8   Bit 7   Bit 6   Bit 5   Bit 4   Bit 3   Bit 2   Bit 1
   +-------+-------+-------+-------+-------+-------+-------+-------+
   |   LAR2[2-1]   |                   LAR1[6-1]                   |
   +-------+-------+-------+-------+-------+-------+-------+-------+
   |           LAR3[4-1]           |          LAR2[6-3]            |
   +-------+-------+-------+-------+-------+-------+-------+-------+
   |  LAR5[2-1]    |                LAR4[5-1]              |LAR3[5]|
   +-------+-------+-------+-------+-------+-------+-------+-------+
   |  LAR7[2-1]    |           LAR6[4-1]           |   LAR5[4-3]   |
   +-------+-------+-------+-------+-------+-------+-------+-------+
                                   |        LAR8[3-1]      |LAR7[3]|
                                   +-------+-------+-------+-------+


   Published specification:
      ETS 300 961 (May 1998), "Digital cellular telecommunications
      system (Phase 2+); Full rate speech; Transcoding (GSM 06.10
      version 5.1.1)".

   Applications which use this media type:
      Voice messaging applications

   Additional information:
      Magic number(s): ?
      File extension(s): .gsm
      Macintosh File Type Code(s):  'gsm '

   Person & email address to contact for further information:
      Laile L. Di Silvestro
      lailed@microsoft.com

      Greg Baribault
      gregbari@microsoft.com

   Intended usage: COMMON

   Author/Change controller:
      Laile L. Di Silvestro
      Greg Baribault





Di Silvestro, Hedberg, Baribault        Expires 10/1/99         [Page 5]


Internet Draft                audio/ms-gsm                        4/1/99


5. Authors' Addresses

   Laile L. Di Silvestro
   Microsoft Corporation
   One Microsoft Way
   Redmond, WA  98052
   lailed@microsoft.com

   Erik Hedberg
   Microsoft Corporation
   One Microsoft Way
   Redmond, WA  98052
   erikhe@microsoft.com

   Greg Baribault
   Microsoft Corporation
   One Microsoft Way
   Redmond, WA  98052
   gregbari@microsoft.com

6.   References

   [GSM]   ETS 300 961 (May 1998), "Digital cellular
           telecommunications system (Phase 2+); Full rate
           speech; Transcoding (GSM 06.10 version 5.1.1)".
   [MIME4] Freed, N., Klensin, J., and J. Postel, "Multipurpose
           Internet Mail Extensions (MIME) Part Four:
           Registration Procedures", RFC 2048, November 1996.
   [VPIM1] Vaudreuil, G., "Voice Profile for Internet Mail", RFC
           1911, February 1996.
   [VPIM2] Vaudreuil, G., and G. Parsons, "Voice Profile for
           Internet Mail - version 2", RFC 2421, September 1998.
   [VPIM3] Vaudreuil, Greg, "Voice Profile for Internet Mail,
           Version 2", Work In Progress, <draft-ema-VPIMv3-
           00.txt>, December 1998.
   [REQ]   Bradner, S., "Key words for use in RFCs to Indicate
           Requirement Levels", BCP 14, RFC 2119, March 1997.
















Di Silvestro, Hedberg, Baribault        Expires 10/1/99         [Page 6]


Internet Draft                audio/ms-gsm                        4/1/99

7. Full Copyright Statement
   Copyright (C) The Internet Society (1999).  All Rights Reserved.
   This document and translations of it may be copied and furnished
   to others, and derivative works that comment on or otherwise
   explain it or assist in its implementation may be prepared,
   copied, published and distributed, in whole or in part, without
   restriction of any kind, provided that the above copyright notice
   and this paragraph are included on all such copies and derivative
   works.  However, this document itself may not be modified in any
   way, such as by removing the copyright notice or references to the
   Internet Society or other Internet organizations, except as needed
   for the purpose of developing Internet standards in which case the
   procedures for copyrights defined in the Internet Standards process
   must be followed, or as required to translate it into languages
   other than English.
   The limited permissions granted above are perpetual and will not
   be revoked by the Internet Society or its successors or assigns.

   Microsoft hereby grants to the IETF, a perpetual, nonexclusive,
   non-sublicensable, non assignable, royalty-free, world-wide right
   and license under any Microsoft copyrights in this contribution to
   copy, publish and distribute the contribution, as well as a right
   and license of the same scope to any derivative works prepared by
   the IETF and based on, or incorporating all or part of the
   contribution.
   Microsoft further agrees that, upon adoption of this contribution
   as an Internet Standard, Microsoft will grant to any party a
   royalty-free license on other reasonable and non-discriminatory
   terms under applicable Microsoft intellectual property rights to
   implement and use the technology proposed in this contribution for
   the purpose of supporting the Internet Standard .  Microsoft
   expressly reserves all other rights it may have in the material and
   subject matter of this contribution.
   Microsoft expressly disclaims any and all warranties regarding this
   contribution including any warranty that (a) this contribution does
   not violate the rights of others, (b) the owners, if any, of other
   rights in this contribution have been informed of the rights and
   permissions granted to IETF herein, and (c) any required
   authorizations from such owners have been obtained.
   This document and the information contained herein is provided on
   an "AS IS" basis and MICROSOFT DISCLAIMS 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.

   IN NO EVENT WILL MICROSOFT BE LIABLE TO ANY OTHER PARTY INCLUDING
   THE IETF AND ITS MEMBERS FOR THE COST OF PROCURING SUBSTITUTE GOODS
   OR SERVICES, LOST PROFITS, LOSS OF USE, LOSS OF DATA, OR ANY
   INCIDENTAL, CONSEQUENTIAL, INDIRECT, OR SPECIAL DAMAGES WHETHER
   UNDER CONTRACT, TORT, WARRANTY, OR OTHERWISE, ARISING IN ANY WAY
   OUT OF THIS OR ANY OTHER AGREEMENT RELATING TO THIS DOCUMENT,
   WHETHER OR NOT SUCH PARTY HAD ADVANCE NOTICE OF THE POSSIBILITY OF
   SUCH DAMAGES.

Di Silvestro, Hedberg, Baribault        Expires 10/1/99         [Page 7]

Html markup produced by rfcmarkup 1.123, available from https://tools.ietf.org/tools/rfcmarkup/