H.3 Coding of Generic Configuration Frames
28.0623GPPInband Tandem Free Operation (TFO) of speech codecsService descriptionStage 3TS
The coding of Generic Configuration Frames in 8 kBit/s and 16 kBit/s sub-multiplexing follow exactly the same rules. The only difference is that 8k frames carry less configurations bits and may need an extension frames earlier.
H.3.1 Generic Configuration Frame Administration Section
H.3.1.1 Extendability
The first bits of each Generic Configuration Frame is reserved for the configuration frame administration.
FOLLOW: D1, 1 bit.
If FOLLOW is set to "0", then this is the first Generic configuration frame, if FOLLOW is set to"1", then this is a second or further Generic configuration frame.
EXTEND: D2, 1 bit.
If EXTEND is set to "0", then no further Generic configuration frame is following, if EXTEND is set to "1", then an additional Generic configuration frame will follow. This next Generic configuration frame may follow immediately, or with a maximum distance of 3 frames in between to allow "house-keeping" for the active codec type.
Then follows a sub-selector field that allows future extension to the Generic Configuration Frame design.
CON_SEL: D3..D5, 3 bits
Coding: D3.D4.D5 = 0.0.0: TFO_Configuration_Frame, all other codes are reserved.
A receiver that does not understand a (for it) reserved code shall ignore the whole configuration frame.
Note: A potential application in future could be the introduction of a DTMF_Frame.
H.3.1.2 Version Handling
A field for a Version.Subversion is following:
Ver.Sver: D6..D9.D10..D13, 4+4 bits;
Example for Coding: 0101.0001 is used to code "REL 5.1.x".
Details for handling of the version in the TFO procedures are defined in clause 4.3.
H.3.1.3 Configuration Exchange Protocol
Then the next part of each Generic Configuration Frame shall contain the protocol related parameters:
Config_Prot: D14..D16, 3 bits
Mess_No: D17.D18, 2 bits
ParType: D19.D20, 2 bits
The definitions are given in Annex C.
H.3.1.4 System Identification, TFO and DTX control
System Identification (Sys_ID), DTXd, TFOE and OD are included in Generic Configuration Frames:
Sys_ID: D21..D28, 8 bits (see TS 26.103 and Annex A.5).
DTXd: D29, 1 bit
TFOE: D30, 1 bit
OD: D31, 1 bit
H.3.1.5 Specific Section for the Active Codec Type
Now follows a specific section for the Active Codec Type (==Local Used Codec). This section has a flexible design to allow future adaptations. It carries signals that are important for the real-time operation of the active codec type.
Active_Codec_Type: D32..D39, 8 bits
ACT_Specific_Length: D40..D42, 3 bits.
ACT_Specific_Extend: D43, 1 bit.
ACT_Specific_Length defines the length of the proprietary section in multiples of 8 bits (octets).
ACT_Specific_Extend specifies an extension of this, in case these 56 bits are not sufficient. If ACT_Specific_Extend is set to "0", then no additional proprietary section follows. If ACT_Specific_Extend is set to "1" then after the first proprietary section again a second ACT_Specific_Length and ACT_Specific _Extend Field are following, and so on.
H.3.1.5.1 Specific Section for GSM_FR, GSM_HR, GSM_EFR
If the Active Codec Type is either GSM_FR or GSM_HR or GSM_EFR, then the parameters are set to:
ACT_Specific_Length := 0.0.0 (no byte is following)
ACT_Specific_Extend := 0 (no further extension).
H.3.1.5.2 Specific Section for the AMR Narrow Band Family
If the Active Codec Type is either FR_AMR, HR_AMR, UMTS_AMR, UMTS_AMR2 or OHR_AMR,
then the parameters are set to:
ACT_Specific_Length := 0.0.1 (one byte is following)
ACT_Specific_Extend := 0 (no further extension),
and the following parameters are defined in addition:
RIF: D44, 1 bit, Request or Indication Flag, as defined in TS 48.060.
CMI_abs: D45..D47, 3 bits, Codec Mode Indication, as defined in TS 48.060.
CMR_abs: D48..D50, 3 bits, Codec Mode Request, as defined in TS 48.060.
spare: D51, 1 bit, reserved for future use, set to "0".
H.3.1.5.3 Specific Section for the AMR Wide Band Family
If the Active Codec Type is either FR_AMR-WB, UMTS_AMR-WB, OFR_AMR-WB or OHR_AMR-WB,
then the parameters are set to:
ACT_Specific_Length := 0.0.1 (one byte is following)
ACT_Specific_Extend := 0 (no further extension),
and the following parameters are defined in addition:
RIF: D44, 1 bit, Request or Indication Flag, as defined in TS 48.060.
CMI_abs: D45..D47, 3 bits, Codec Mode Indication, as defined in TS 48.060.
CMR_abs: D48..D50, 3 bits, Codec Mode Request, as defined in TS 48.060.
spare: D51, 1 bit, reserved for future use, set to "0".
H.3.1.6 Spare Bits
If bits remain after the last used configuration parameters, see H.3.2, then these bits shall be filled with "0" (spare code in Generic Configuration Frames).
H.3.1.6a TFO and Handover_Notifications Bits
The last field in the first Generic Configuration Frame before CRC is dedicated to TFO and Handover_Notifications:
TFO_HO_NOTIF8k: D115 to D117 in TRAU8k / TFO8k frames and
TFO_HO_NOTIF16k: D266 to D268 in TRAU16k / TFO16k frames.
See Table 5.2.2.1-2, bits c9 to c11 for detailed coding.
If more than one Generic Configuration Frame is necessary for the whole message, then only the first Generic Configuration Frame shall contain these TFO and Handover_Notification bits.
If a Generic Configuration Frame uses the code "Handover_Soon", then the Configuration Parameter Section (H.3.2) is dedicated to the situation after the announced handover.
H.3.1.7 Error Detection and Error Handling
A Generic Configuration Frame contains important information and is protected by an 8-bit-CRC including C1..C5, all data bits and all spare bits.
The 8-bit-CRC parity bits shall be placed at a fixed position at the very end of the Generic Configuration Frame:
CRC8k: D118 to D125 in TRAU8k / TFO8k frames and
CRC16k: D269 to D276 in TRAU16k / TFO16k frames.
These 8 parity bits are in both cases generated by the cyclic generator polynomial:
g(D) = D8 + D4 + D3 + D2 + 1.
The encoding is performed in a systematic form, which means that, in GF(2), the polynomial:
– b(1)D(N+8-1) + b(2)D(N+8-2) +…+b(N)D8 + p(1)D7 + p(2)D6 +…+ p(7)D1 + p(8);
– p(1) ‑ p(8): the parity bits (D118 – D125 or the parity bits (D269 – D276);
– b(1) ‑ b(N): the data bits (C1- C5, D1-D117) or the data bits (C1- C5, D1 – D268);
when divided by g(D), yields a remainder equal to 0.
A Generic Configuration Frame with CRC-error shall be regarded as invalid and shall be ignored, i.e. its parameters shall not be used and it shall not be acknowledged. A TRAU passing these Generic Configuration Frames from the Abis interface to the A interface or vice versa shall not correct the CRC, if errors are detected.
If the TRAU has to recalculate the CRC and it detects at the end that the incoming CRC indicated a transmission error, then the TRAU shall deliberately invert the newly calculated CRC before sending it along.
H.3.2 Configuration Parameter Section
The Configuration Parameter section fits between the ACT specific section and the TFO and Handover_Notification field. If not enough space is left there, then another Generic Configuration Frame shall be used for the remaining parameter bits. These remaining bits shall be placed in the next Configuratioin Frame starting after the ACT specific section, and so on.
H.3.2.1 Mapping for Single Codec Type
An exactly defined Mapping between TS 26.103 and TFO_Configuration_Frames exists.
This is defined as follows:
The "Single_Codec" identifier as defined in TS 26.103 is omitted.
The "Length_Indicator" is shortened to 3 bits and an "Extension_Indicator" is introduced in addition.
That allows directly up to 7 octets for parameters per Codec Type. If this is not sufficient (potentially in future cases), then the "Extension_Indicator" is set to "1" and then a Length_Indicator and Extension_Indicator is again following with again a parameter field of up to 7 octets for the remaining configuration parameters, and so on.
The Length_Indicator counts all octets after the OID_Indicator.
The "Compatibility Information" is omitted, when not necessary. This is indicated by a single bit ("Compatibility_Information_Indicator") that is set to "0" normally and to "1" if the Compatibility_Information octet is present.
The "Organisation IDentifier" (OID) is omitted, when not necessary. This is indicated by a single bit ("OID_Indicator") that is set to "0" normally and to "1", if the OID octet is present.
When the OID is omitted then OID=="ETSI" shall be assumed.
The "CoID" (Codec Type Identifier) is exactly copied (8 bits).
The configuration parameters are exactly copied as specified in TS 26.103, MSB first.
Note: in that light the definition for AMR-WB is cumbersome, because it is somewhat "octet-hungry".
Table H.3.2-1 summarises the design for the example "FR AMR" as one Codec Type in the Codec List.
Table H.3.2-1 Design of the Codec Type Configuration for the example FR AMR
|
Name |
TS 26.103 |
TS 28.062 |
Comment |
|
Single_Codec_Indicator |
8 bits |
0 bits |
omitted in TS 28.062 |
|
Length_Indicator |
8 bits |
3 bits |
"1.0.0" (4 octets following after the Organisation_Identifier_Indicator) |
|
Extension_Indicator |
– |
1 bits |
"0" no further Extension necessary |
|
Compatibility_Information_Indicator |
– |
1 bit |
"0" Compatibility_Information is omitted |
|
Organisation_Identifier_Indicator |
1 bit |
1 bit |
"0" Organisation_Identifier is omitted |
|
Compatibility_Information |
8 bits |
0 bits |
omitted, when not indicated |
|
Organisation_Identifier |
8 bits |
0 bits |
omitted, when not indicated |
|
Codec_Type_Identifier |
8 bits |
8 bits |
"FR_AMR_CoID" |
|
ACS |
8 bits |
8 bits |
0.1.0.0.1.1.0.1 (e.g.) |
|
SCS |
8 bits |
8 bits |
1.1.1.1.1.1.1.1 (can be omitted) |
|
OM, MACS |
8 bits |
8 bits |
0.0.0.0.0.0.0.0 (can be omitted) |
For the example "AMR with all configuration parameters present" the coding in TS 26.103 takes 8*8=64 bits, while the coding in the Configuration frame takes 6+8+3*8=38 bits, with de facto identical contents. In the case of full
support (i.e. SCS and OM, MACS omitted) the relation is 48 bits to 22 bits.
H.3.2.2 Codec List
If more Codec Types are present in the Codec List, then they shall follow one by one, each one coded as specified in H3.2.1 above.
The Codec Types shall be ordered according to their preference.
Per default the most preferred Codec Type shall be the first in the list (as in TS 26.103). Then Par_Type shall be set to "0.1" (local configuration parameters) or "1.0" (distant configuration parameters).
The first Codec Type in the Codec_List shall be the optimal Codec Type, when sent by the TRAU downlink with Par_Type set to "1.1".
Annex I (informative):
Change History
|
Change history |
|||||||
|---|---|---|---|---|---|---|---|
|
Date |
TSG SA# |
TSG Doc. |
CR |
Rev |
Subject/Comment |
Old |
New |
|
2001-03 |
11 |
SP-010096 |
Version for Release 4 |
4.0.0 |
|||
|
2001-06 |
12 |
SP-010310 |
001 |
1 |
Reference to a deleted TFO message |
4.0.0 |
4.1.0 |
|
2001-08 |
Clean-up |
4.1.0 |
4.1.1 |
||||
|
2001-12 |
14 |
SP-010704 |
002 |
Corrections |
4.1.1 |
4.2.0 |
|
|
2001-12 |
14 |
SP-010704 |
003 |
Corrections |
4.1.1 |
4.2.0 |
|
|
2002-03 |
15 |
SP-020090 |
004 |
Correction of OM & OD bits mapping in TFO 16k frames |
4.2.0 |
4.3.0 |
|
|
2002-03 |
15 |
SP-020090 |
005 |
1 |
Inclusion of the Non_Speech TFO frames in conditions for TFO_Frame |
4.2.0 |
4.3.0 |
|
2002-03 |
15 |
SP-020090 |
007 |
2 |
Corrections in TFO Protocol Tables |
4.2.0 |
4.3.0 |
|
2002-03 |
15 |
SP-020090 |
013 |
Corrected C-Code for AMR TFO decision rules |
4.2.0 |
4.3.0 |
|
|
2002-03 |
15 |
SP-020090 |
016 |
Corrections |
4.2.0 |
4.3.0 |
|
|
2002-03 |
15 |
SP-020091 |
009 |
Modification of TFO_Messages for AMR-WB introduction |
4.3.0 |
5.0.0 |
|
|
2002-03 |
15 |
SP-020091 |
010 |
2 |
Introduction of Generic Configuration Frames into TS 28.062, Annex H |
4.3.0 |
5.0.0 |
|
2002-03 |
15 |
SP-020091 |
015 |
1 |
Inclusion of AMR-WB codec types and codec type OHR_AMR (AMR-NB on 8PSK-HR channel) into TFO |
4.3.0 |
5.0.0 |
|
2002-03 |
15 |
SP-020092 |
14 |
Introduction of AMR-WB codec types and codec type OHR_AMR into reference implementation C-Code of AMR TFO decision rules |
4.3.0 |
5.0.0 |
|
|
2002-06 |
16 |
SP-020228 |
017 |
1 |
Editorial corrections and additions |
5.0.0 |
5.1.0 |
|
2002-06 |
16 |
SP-020228 |
019 |
2 |
Additional TFO_Message Elements for Immediate Codec Type Optimisation |
5.0.0 |
5.1.0 |
|
2002-06 |
16 |
SP-020228 |
020 |
2 |
Corrections to TS 28.062, sections 4 to 8 |
5.0.0 |
5.1.0 |
|
2002-06 |
16 |
SP-020228 |
021 |
3 |
Corrections to TS 28.062, Annex C |
5.0.0 |
5.1.0 |
|
2002-06 |
16 |
SP-020228 |
022 |
2 |
TFO Version Handling |
5.0.0 |
5.1.0 |
|
2002-06 |
16 |
SP-020228 |
023 |
2 |
Configuration Exchange in Annex C |
5.0.0 |
5.1.0 |
|
2002-06 |
16 |
SP-020228 |
024 |
2 |
Corrections to Annex H |
5.0.0 |
5.1.0 |
|
2002-06 |
16 |
SP-020228 |
026 |
1 |
Corrections to sections 9 and 10 |
5.0.0 |
5.1.0 |
|
2002-06 |
16 |
SP-020228 |
027 |
1 |
Immediate Codec Type Optimization |
5.0.0 |
5.1.0 |
|
2002-09 |
17 |
SP-020437 |
030 |
1 |
TFO-Signalling for allowed AMR-WB Configurations |
5.1.0 |
5.2.0 |
|
2002-09 |
17 |
SP-020437 |
031 |
2 |
Simplified TFO Decision for AMR-WB |
5.1.0 |
5.2.0 |
|
2002-09 |
17 |
SP-020438 |
33 |
2 |
TFO-Signalling for preferred AMR-NB Configurations |
5.1.0 |
5.2.0 |
|
2002-09 |
17 |
SP-020438 |
34 |
TFO Version Handling |
5.1.0 |
5.2.0 |
|
|
2002-12 |
18 |
SP-020696 |
036 |
1 |
Correction to TFO_Term state description |
5.2.0 |
5.3.0 |
|
2002-12 |
18 |
SP-020696 |
037 |
1 |
TFO version handling |
5.2.0 |
5.3.0 |
|
2002-12 |
18 |
SP-020696 |
038 |
1 |
Corrections to the TFO standard (wrong specification references) |
5.2.0 |
5.3.0 |
|
2002-12 |
18 |
SP-020696 |
039 |
1 |
Correction of TFO_REQ message for AMR-WB |
5.2.0 |
5.3.0 |
|
2003-09 |
21 |
SP-030451 |
040 |
Removal of Pre-Handover Notification for UMTS |
5.3.0 |
5.4.0 |
|
|
2004-09 |
25 |
SP-040647 |
041 |
2 |
Harmonisation of AMR Configurations |
5.4.0 |
6.0.0 |
|
2004-12 |
26 |
SP-040846 |
044 |
TFO/TrFO Compatibility of UMTS_AMR and UMTS_AMR2 |
6.0.0 |
6.1.0 |
|
|
2004-12 |
26 |
SP-040846 |
047 |
Operator Guidelines for UMTS_AMR and AMR Harmonization |
6.0.0 |
6.1.0 |
|
|
2005-12 |
30 |
SP-050792 |
0048 |
2 |
PCM-Idle Pattern Problem |
6.1.0 |
6.2.0 |
|
2005-12 |
30 |
SP-050792 |
0049 |
1 |
TFO Decision on Preferred Configurations |
6.1.0 |
6.2.0 |
|
2005-12 |
30 |
SP-050792 |
0050 |
1 |
TFO Decision Algorithm in C-Code |
6.1.0 |
6.2.0 |
|
2005-12 |
30 |
SP-050792 |
0051 |
2 |
Codec Type in TFO Frames |
6.1.0 |
6.2.0 |
|
2005-12 |
30 |
SP-050792 |
0052 |
1 |
Rate Control on Call Setup |
6.1.0 |
6.2.0 |
|
2005-12 |
30 |
SP-050792 |
0053 |
2 |
Determination of the TFO Frame Format |
6.1.0 |
6.2.0 |
|
2006-09 |
33 |
SP-060597 |
0055 |
1 |
Signature in TFO_ACK |
6.2.0 |
6.3.0 |
|
2006-09 |
33 |
SP-060597 |
0056 |
1 |
Uplink CMI too high |
6.2.0 |
6.3.0 |
|
2006-09 |
33 |
SP-060597 |
0057 |
1 |
AMR attributes in TFO_REQ_L |
6.2.0 |
6.3.0 |
|
2006-09 |
33 |
SP-060597 |
0058 |
1 |
Removal of AMR-WB related erroneous text |
6.2.0 |
6.3.0 |
|
2007-06 |
36 |
SP-070316 |
0059 |
1 |
Correction of generic configuration frames definition |
6.3.0 |
6.4.0 |
|
2007-06 |
36 |
Version for Release 7 |
6.4.0 |
7.0.0 |
|||
|
2008-12 |
42 |
Version for Release 8 |
7.0.0 |
8.0.0 |
|||
|
2009-03 |
43 |
SP-090016 |
0060 |
TFO – Correction of References |
8.0.0 |
8.1.0 |
|
|
2009-12 |
46 |
Version for Release 9 |
8.1.0 |
9.0.0 |
|||
|
2011-03 |
51 |
Version for Release 10 |
9.0.0 |
10.0.0 |
|||
|
2012-09 |
57 |
Version for Release 11 |
10.0.0 |
11.0.0 |
|||
|
2014-09 |
65 |
Version for Release 12 |
11.0.0 |
12.0.0 |
|||
|
2015-12 |
70 |
Version for Release 13 |
12.0.0 |
13.0.0 |
|||
|
Change history |
|||||||
|
Date |
Meeting |
TDoc |
CR |
Rev |
Cat |
Subject/Comment |
New version |
|
03-2017 |
75 |
Version for Release 14 |
14.0.0 |
||||
|
06-2018 |
80 |
Version for Release 15 |
15.0.0 |
||||
|
2020-07 |
– |
– |
– |
– |
– |
Update to Rel-16 version (MCC) |
16.0.0 |
|
2022-04 |
– |
– |
– |
– |
– |
Update to Rel-17 version (MCC) |
17.0.0 |