8 Nb Interface User Plane (CN)
26.2023GPPAdaptive Multi-Rate - Wideband (AMR-WB) speech codecInterface to Iu, Uu and NbRelease 17Speech codec speech processing functionsTS
The data structures exchanged on the Nb interface are symmetrical, i.e. the structures of the sent and received data frames are identical.
8.1 Frame structure on the Nb UP transport protocol
Delivery of erroneous SDUs for AMR-WB data and PCM coded speech on the Nb interface shall be set to: "YES".
Erroneous speech frames may be used to assist the error concealment procedures. Therefore, according to [1] and [6], PDU Type 0 (with payload CRC) shall be used for the transport of AMR-WB coded speech on the Nb interface.
PDU Type 0 (with payload CRC) shall be used for the transport of PCM coded speech on the Nb interface, too.
8.1.1 Initialisation
The initialisation procedure is used for support mode. At the initialisation several parameters are set by the CN. The initialisation procedure for the Nb Interface is described in [6].
8.1.2 Time Alignment Procedure
The handling of Time Alignment on the Nb Interface is described in [6].
The Time alignment procedure shall be dismissed in case of TFO and TrFO.
8.2 Mapping of the bits
8.2.1 Mapping for AMR-WB frames
The mapping of the bits between the generic AMR-WB frames and the PDU for the Nb Interface is identical to the mapping on the Iu Interface. In case of TrFO the MGW relays the AMR-WB frames from the Iu Interface unaltered to the Nb Interface and vice versa, as described in [6].
8.2.2 Mapping for PCM Coded Speech
In case of transcoding within the MGW from PCM coded speech to AMR-WB frames and vice versa the mapping for the PCM coded speech on the Nb Interface shall be as defined in Table 8-1.
Table 8-1: Mapping of PCM Coded Speech onto Nb PDU, Type 0
|
PDU field |
Comment |
|
PDU Type |
Type 0 (with Payload CRC) |
|
Frame Number |
as defined in [6] |
|
FQC |
set to "good" |
|
RFCI |
initialise by MGW, see [6], |
|
Header CRC |
as defined in [6] |
|
Payload CRC |
as defined in [6] |
|
Payload Field |
40 octets of PCM coded speech, |
8.3 Frame handlers
Nb PDU Frame handling functions are described in [6].
Annex A (informative):
Change history
|
Change history |
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|
Date |
TSG # |
TSG Doc. |
CR |
Rev |
Subject/Comment |
Old |
New |
|
03-2001 |
11 |
SP-010091 |
Presented as version 2.0.0 for approval |
5.0.0 |
|||
|
09-2002 |
SP-020437 |
001 |
2 |
Consideration of allowed Configurations for AMR-WB |
5.0.0 |
5.1.0 |
|
|
12-2004 |
26 |
Version for Release 6 |
5.1.0 |
6.0.0 |
|||
|
06-2007 |
36 |
Version for Release 7 |
6.0.0 |
7.0.0 |
|||
|
09-2008 |
41 |
SP-080475 |
003 |
2 |
Addition of CS over IP User Plane |
7.0.0 |
8.0.0 |
|
12-2008 |
42 |
Update of LTE logo and Copyright statement |
8.0.0 |
8.0.1 |
|||
|
12-2009 |
46 |
Version for Release 9 |
8.0.1 |
9.0.0 |
|||
|
03-2011 |
51 |
Version for Release 10 |
9.0.0 |
10.0.0 |
|||
|
06-2012 |
56 |
SP-120223 |
0005 |
Correction of Example Text Regarding Number of Class A and B bits and RAB sub flows |
10.0.0 |
10.1.0 |
|
|
09-2012 |
57 |
Version for Release 11 |
10.1.0 |
11.0.0 |
|||
|
09-2014 |
65 |
Version for Release 12 |
11.0.0 |
12.0.0 |
|||
|
12-2015 |
70 |
Version for Release 13 |
12.0.0 |
13.0.0 |
|||
|
Change history |
|||||||
|
Date |
TSG # |
TSG Doc. |
CR |
Rev |
Cat |
Subject/Comment |
New version |
|
2016-09 |
73 |
SP-160601 |
0006 |
1 |
F |
Clarification to avoid rate adaptation quality issues in uplink for UTRAN |
14.0.0 |
|
2018-06 |
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 |