13 Voice services over Adaptive Multi-user Channels on One Slot (VAMOS)
3GPP45.001General descriptionGSM/EDGE Physical layer on the radio pathRelease 17TS
13.1 General
VAMOS allows multiplexing of two users simultaneously on the same physical resource in the circuit switched mode both in downlink and in uplink, using the same timeslot number, ARFCN and TDMA frame number. Hence, a basic physical channel capable of VAMOS supports up to 4 TCH channels along with their associated control channels (FACCH and SACCH).
The channel organization for TCH, FACCH and SACCH/T in VAMOS mode shall be done as described in 3GPP TS 45.002. Some exemplary channel organizations are depicted in Figure 5, where only one time slot per TDMA frame is considered.
The FACCH is transmitted by pre-empting half or all of the information bits of the bursts of the TCH to which it is associated (see 3GPP TS 45.003).
Figure 5: TCH and ACCH organization in VAMOS mode
A pair of TCH channels along with their associated control channels sharing the same timeslot number, ARFCN and TDMA frame number is referred to as a VAMOS pair. Up to 2 VAMOS pairs can be supported by a basic physical channel capable of VAMOS. The TCH channels along with their associated control channels in a VAMOS pair are said to be in VAMOS mode and are referred to as VAMOS subchannels. In a VAMOS pair, each VAMOS subchannel shall be assigned a training sequence which is different from the training sequence assigned to the other VAMOS subchannel in that VAMOS pair (see 3GPP TS 45.002).
The following combinations of TCH channels along with their corresponding associated control channels are allowed to form a VAMOS pair:
i) 2 full rate TCH channels where each TCH/F channel is a TCH/FS, TCH/EFS, TCH/AFS or TCH/WFS channel.
ii) 1 full rate TCH channel where the TCH/F channel is a TCH/FS, TCH/EFS, TCH/AFS or TCH/WFS and 1 half rate TCH channel where the TCH/H channel is a TCH/HS or TCH/AHS channel.
iii) 2 half rate TCH channels where each TCH/H channel is a TCH/HS or TCH/AHS channel.
Note 1: In combination ii) the basic physical channel capable of VAMOS may support two VAMOS pairs, one pair with TCH/F and TCH/H sub-channel number 0 and another pair with the same TCH/F paired with TCH/H sub-channel number 1
Note 2: In combination iii) the basic physical channel capable of VAMOS may support two VAMOS pairs, one sharing TCH/H sub-channel number 0 and one sharing TCH/H sub-channel number 1.
13.2 Network and MS Support for VAMOS
A network supporting VAMOS may assign a mobile station not indicating explicit support for VAMOS on a VAMOS pair provided the training sequence assigned on the corresponding VAMOS subchannel is chosen from a TSC Set (see 3GPP TS 45.002) supported by the MS.
An MS shall indicate whether or not it supports VAMOS (see 3GPP TS 24.008). For an MS supporting VAMOS, multiple levels of support are defined. An MS supporting VAMOS shall indicate the supported VAMOS level (see 3GPP TS 24.008).
– An MS supporting VAMOS I, VAMOS II or VAMOS III (see 3GPP TS 24.008) shall support the set of training sequences in TSC Set 1 and TSC Set 2 (see 3GPP TS 45.002).
– If an MS indicates support for VAMOS II or VAMOS III (see 3GPP TS 24.008) then the MS shall support the mapping of logical channels onto the physical channels as shown in table 1a and/or table 1b of 3GPP TS 45.002.
– An MS indicating support for VAMOS shall also indicate support for either "Downlink Advanced Receiver Performance – phase I" or "Downlink Advanced Receiver Performance – phase II", and for "Repeated SACCH and Repeated Downlink FACCH" (see 3GPP TS 24.008). If an MS supports VAMOS III, then irrespective of whether it indicates DARP I or DARP II capability, it shall meet DARP II GMSK speech channel and associated control channel performance requirements.
– If at least one MS assigned to a VAMOS pair indicates explicit support for VAMOS, then the network shall use training sequences for the two subchannels in the VAMOS pair according to one of the following options:
– a training sequence from TSC Set 1 for one of the VAMOS subchannels and the training sequence with the same training sequence code from TSC Set 2 for the other VAMOS subchannel.
– a training sequence chosen from TSC Set 3 for one of the VAMOS subchannels and the training sequence with the same training sequence code from TSC Set 4 for the other VAMOS subchannel. This option may be used only if both MS have indicated support for Extended TSC Sets for circuit switched channels (see 3GPP TS 24.008).
13.3 Downlink Functionality
In downlink, a pair of corresponding bits from the TCHs and associated control channels in a VAMOS pair shall be mapped on to an AQPSK modulation symbol (see 3GPP TS 45.004) and shall be received by 2 different mobile stations in the same cell. Each MS shall decode the desired signal of its TCH and associated control channels, and shall perform the radio link measurements as stated in 3GPP TS 45.008.
13.3.1 Modulation
The data from both subchannels of a VAMOS pair shall be mapped onto the AQPSK symbols pair wise as shown in the Figure 6. Detailed description of modulation and pulse shaping is provided in 3GPP TS 45.004.
Figure 6: AQPSK Modulation to map bits from a VAMOS pair on a burst in downlink
13.3.1.1 Selection of modulation format
In downlink, for a VAMOS pair, when DTX is employed for the TCH channels, AQPSK modulation as shown above shall be used when on a given physical resource both the TCH channels in the VAMOS pair have bursts scheduled for transmission simultaneously. If only one of the TCH channels in a VAMOS pair has bursts scheduled for transmission, with the other TCH channel being in DTX state (having no bursts scheduled for transmission, see 3GPP TS 45.008), the BSS shall send GMSK normal bursts. If none of the TCH channels in the VAMOS pair has bursts scheduled for transmission, then nothing is transmitted.
NOTE: A burst scheduled for transmission in downlink for a VAMOS subchannel may contain bits from one of the following types of frames: speech frame, FACCH frame, SACCH frame, SID frame, SID_UPDATE frame, SID_FIRST frame, ONSET frame, RATSCCH frame.
13.3.2 Burst Format
When the modulation format used is GMSK (see sub clause 13.3.1.1), the burst format used in downlink is GMSK normal burst at normal symbol rate (see 3GPP TS 45.002). When the modulation format used is AQPSK (see sub clause 13.3.1.1), the burst format used in downlink is normal burst for the AQPSK modulation (see 3GPP TS 45.002).
13.3.3 Associated Control Channels
13.3.3.1 FACCH
The channel coding for FACCH associated to a TCH in VAMOS mode is identical to the corresponding coding for the single user case, i.e. FACCH/F for full rate or FACCH/H for half rate. (see 3GPP TS 45.002 and 3GPP TS 45.003). Repeated FACCH may be used in downlink.
13.3.3.2 SACCH
The channel coding for SACCH associated to a TCH in VAMOS mode is identical to the corresponding coding for the single user case, i.e. SACCH/TF, SACCH/TPF for full rate or SACCH/TH, SACCH/TPH for half rate (see 3GPP TS 45.002 and 3GPP TS 45.003). The TDMA frame mapping for SACCH in VAMOS mode is done as described in 3GPP TS 45.002. Repeated SACCH may be used in downlink.
13.4 Uplink Functionality
In uplink, when in VAMOS mode, two GMSK modulated signals are transmitted simultaneously on the same radio resource, identified by the same timeslot number, ARFCN and TDMA frame number, in a given cell by two different mobile stations. The BSS shall decode the TCH and the associated control channels for the two desired signals and shall perform radio link control procedures for the two VAMOS subchannels as stated in 3GPP TS 45.008.
13.4.1 Modulation, Burst Format and Training Sequence
Each mobile station in VAMOS mode shall use in uplink GMSK modulation, normal burst format at normal symbol rate and use the training sequence assigned by the BSS.
13.4.2 Associated Control Channels
13.4.2.1 FACCH
In uplink FACCH transmission associated to a TCH in VAMOS mode is identical to the single user case, i.e. FACCH/F for full rate or FACCH/H for half rate (see 3GPP TS 45.002 and 3GPP TS 45.003).
13.4.2.2 SACCH
In uplink the channel coding of SACCH associated to a TCH in VAMOS mode is identical to the single user case, i.e. SACCH/TF or SACCH/TPF for full rate and SACCH/TH or SACCH/TPH for half rate (see 3GPP TS 45.002 and 3GPP TS 45.003). The TDMA frame mapping for SACCH in VAMOS mode is done as described in 3GPP TS 45.002. Repeated SACCH may be used in uplink.
13.5 Channel Mode Adaptation
Channel Mode Adaptation is used for assigning individual TCH channels in VAMOS mode or in single user TCH mode. Assignments are performed according to decisions made by the BSS and if necessary, are communicated to the respective MS in layer 3 control messages. If the physical resource and the TSC assigned on the physical resource do not change, the channel mode adaptation shall be performed without signalling on the associated FACCH. Both uplink and downlink channel modes are changed during the channel mode adaptation process.
Annex A (informative):
Reference configuration
Figure A1: Reference configuration
Annex B (informative):
Relations between specification
Figure B1: Relations between specifications
Annex C (informative):
Change history
|
SPEC |
SMG# |
CR |
PHASE |
VERS |
NEW_VERS |
SUBJECT |
||
|
05.01 |
S18 |
A005 |
2+ |
4.6.0 |
5.0.0 |
Addition of ASCI features |
||
|
05.01 |
S20 |
A006 |
2+ |
5.0.0 |
5.1.0 |
Introduction of high speed circuit switched data |
||
|
05.01 |
s21 |
A007 |
2+ |
5.1.0 |
5.2.0 |
Introduction of R-GSM band |
||
|
05.01 |
s22 |
A009 |
2+ |
5.2.0 |
5.3.0 |
Clarification of the frequency definition text in section 9 |
||
|
05.01 |
s24 |
A010 |
R97 |
5.3.0 |
6.0.0 |
Introduction of GPRS |
||
|
05.01 |
s25 |
A012 |
R97 |
6.0.0 |
6.1.0 |
14.4kbps Data Service |
||
|
05.01 |
s25 |
A013 |
R97 |
6.0.0 |
6.1.0 |
Renaming of GPRS RR states |
||
|
05.01 |
s28 |
A014 |
R98 |
6.1.1 |
7.0.0 |
Harmonization between GSM and PCS 1900 standard |
||
|
05.01 |
s28 |
A015 |
R98 |
6.1.1 |
7.0.0 |
Introduction of CTS in 05.01 |
||
|
05.01 |
s28 |
A016 |
R98 |
6.1.1. |
7.0.0 |
Introduction of AMR in 05.01 |
||
|
05.01 |
s29 |
A017 |
R99 |
7.0.0. |
8.0.0 |
Introduction of GSM 400 in 05.01 |
||
|
05.01 |
s29 |
A018 |
R99 |
7.0.0 |
8.0.0 |
05.01 changes for ECSD FACCH |
||
|
05.01 |
s30 |
A020 |
R99 |
8.0.1 |
8.1.0 |
Correction of AMR Block Structure Parameters, Introduction of TCH/EFS |
||
|
05.01 |
s30 |
A021 |
R99 |
8.0.1 |
8.1.0 |
Introduction of the definition of the PDTCH for EGPRS |
||
|
05.01 |
s30 |
A022 |
R99 |
8.0.1 |
8.1.0 |
EDGE Compact logical channels |
||
|
05.01 |
s30b |
A023 |
R99 |
8.1.0 |
8.2.0 |
Support of Slow Frequency Hopping for EGPRS COMPACT |
||
|
05.01 |
s31 |
A024 |
R99 |
8.2.0 |
8.3.0 |
Complete Frequency Hopping on COMPACT |
||
|
05.01 |
s32 |
A026 |
R99 |
8.3.0 |
8.4.0 |
Definition of PDCH/H and alignment with DTM |
||
|
September 2000 – 3GPP TSG-GERAN |
||||||||
|
05.01 |
G01 |
A028 |
R99 |
8.4.0 |
8.5.0 |
CR 05.01-A028 DTM (R99) |
||
|
05.01 |
G01 |
A029 |
R99 |
8.4.0 |
8.5.0 |
CR 05.01-A029 DTM+EGPRS (R99) |
||
|
05.01 |
G01 |
A031 |
R99 |
8.4.0 |
8.5.0 |
CR 05.01-A031 Minimum Mobile Station Class and Channelization Capabilities |
||
|
GERAN |
Release 4 |
|||||||
|
05.01 / 45.001 |
G01 |
A030 |
Rel4 |
8.5.0 |
4.0.0 |
CR 05.01-A030 Introduction of GSM 700 (Release 4) |
||
|
4.0.0 |
4.0.1 |
Oct 2000: References corrected. |
||||||
|
Change history |
|||||||
|
Date |
TSG GERAN# |
TSG Doc. |
CR |
Rev |
Subject/Comment |
Old |
New |
|
2001-01 |
03 |
GP-010240 |
001 |
Introduction of Wideband AMR for GMSK modulated speech channel |
4.0.1 |
5.0.0 |
|
|
2001-08 |
06 |
GP-011917 |
003 |
1 |
Introduction of EPC channels |
5.0.0 |
5.1.0 |
|
2001-11 |
07 |
GP-012350 |
004 |
Introduction of adaptive half rate speech channels with 8-PSK modulation |
5.1.0 |
5.2.0 |
|
|
2001-11 |
07 |
GP-012364 |
006 |
Correction of description Wideband AMR channel coding |
5.1.0 |
5.2.0 |
|
|
2001-11 |
07 |
GP-012767 |
008 |
1 |
Correction of references to relevant 3GPP TSs |
5.1.0 |
5.2.0 |
|
2001-11 |
07 |
GP-012509 |
010 |
Coding rate of MCS3 |
5.1.0 |
5.2.0 |
|
|
2002-04 |
09 |
GP-021168 |
012 |
1 |
Alignment of number of codecs for WB-AMR to proposed set |
5.2.0 |
5.3.0 |
|
2002-04 |
09 |
GP-020885 |
013 |
Decimal Sign |
5.2.0 |
5.3.0 |
|
|
2002-04 |
09 |
GP-021204 |
014 |
1 |
Introduction of AMR-WB on 8PSK modulated speech traffic channels |
5.2.0 |
5.3.0 |
|
2002-06 |
10 |
GP-021434 |
016 |
Corrections and clean up |
5.3.0 |
5.4.0 |
|
|
2002-06 |
10 |
GP-021629 |
018 |
Miscellaneous corrections |
5.3.0 |
5.4.0 |
|
|
2002-11 |
12 |
GP-023113 |
020 |
CRC Sizes for AMR-WB |
5.4.0 |
5.5.0 |
|
|
2002-11 |
12 |
GP-023321 |
019 |
2 |
Implementation of new frequency ranges |
5.5.0 |
6.0.0 |
|
2003-04 |
14 |
GP-030986 |
023 |
1 |
MCS-3 padding for MCS-8 retransmission |
6.0.0 |
6.1.0 |
|
2003-11 |
17 |
GP-032459 |
024 |
2 |
Flexible Layer One |
6.1.0 |
6.2.0 |
|
2003-11 |
17 |
GP-032556 |
027 |
Correction due to change of DTM core capability |
6.1.0 |
6.2.0 |
|
|
2004-02 |
18 |
GP-040362 |
028 |
Correction on MS support of EGPRS coding schemes |
6.2.0 |
6.3.0 |
|
|
2004-06 |
20 |
GP-041231 |
030 |
Correction of Figure 2a1 |
6.3.0 |
6.4.0 |
|
|
2004-11 |
22 |
GP-042469 |
034 |
Introduction of MBMS |
6.4.0 |
6.5.0 |
|
|
2004-11 |
22 |
GP-042785 |
035 |
Removal of PTM-M |
6.4.0 |
6.5.0 |
|
|
2004-11 |
22 |
GP-042879 |
038 |
1 |
FLO-compatible quick fix for VT over GERAN |
6.4.0 |
6.5.0 |
|
2005-04 |
24 |
GP-050779 |
042 |
Introduction of GSM 710 |
6.5.0 |
7.0.0 |
|
|
2005-06 |
25 |
GP-051714 |
043 |
1 |
Introduction of T-GSM 810 |
7.0.0 |
7.1.0 |
|
2005-11 |
27 |
GP-052846 |
0045 |
1 |
MBMS transfer mode |
7.1.0 |
7.2.0 |
|
2006-06 |
30 |
GP-061109 |
0046 |
Correction of terminology: ‘allocation’ vs. ‘assignment’ |
7.2.0 |
7.3.0 |
|
|
2007-05 |
34 |
GP-070789 |
0049 |
Miscellaneous corrections |
7.3.0 |
7.4.0 |
|
|
2007-08 |
35 |
GP-071514 |
0047 |
2 |
Introduction of Reduced TTI and Fast Ack/Nack Reporting |
7.4.0 |
7.5.0 |
|
2007-08 |
35 |
GP-071491 |
0050 |
1 |
Introduction of RED HOT and HUGE |
7.4.0 |
7.5.0 |
|
2007-11 |
36 |
GP-071673 |
0051 |
Removal of RL TBF in FANR procedures and miscellaneous corrections |
7.5.0 |
7.6.0 |
|
|
2007-11 |
36 |
GP-071699 |
0052 |
Corrections for REDHOT, HUGE and LATRED |
7.5.0 |
7.6.0 |
|
|
2008-02 |
37 |
GP-080365 |
0053 |
1 |
Corrections for LATRED |
7.6.0 |
7.7.0 |
|
2008-08 |
39 |
GP-081414 |
0055 |
2 |
Aligning GSM 700 frequency range and usage with other 3GPP access technologies |
7.7.0 |
7.8.0 |
|
2008-12 |
40 |
Version for Release 8 |
7.8.0 |
8.0.0 |
|||
|
2009-05 |
42 |
GP-091047 |
0057 |
2 |
Introduction of VAMOS |
8.0.0 |
9.0.0 |
|
2009-11 |
44 |
GP-092159 |
0063 |
2 |
TSC Pairing for VAMOS aware UEs |
9.0.0 |
9.1.0 |
|
2009-11 |
44 |
GP-092347 |
0066 |
1 |
Removal of mandatory support for P-channels by mobile stations in A/Gb mode |
9.0.0 |
9.1.0 |
|
2009-11 |
44 |
GP-092350 |
0068 |
2 |
Removal T-GSM 900 |
9.0.0 |
9.1.0 |
|
2010-03 |
45 |
GP-100612 |
0058 |
5 |
Introduction of Shifted SACCH scheme for VAMOS |
9.1.0 |
9.2.0 |
|
2010-09 |
47 |
GP-101551 |
0071 |
2 |
Introduction of VAMOS performance levels |
9.2.0 |
9.3.0 |
|
2011-03 |
49 |
Version for Release 10 |
9.3.0 |
10.0.0 |
|||
|
2011-11 |
52 |
GP-111848 |
0074 |
2 |
Clarification of mandatory DARP and Repeated ACCH support for VAMOS feature |
10.0.0 |
10.1.0 |
|
2012-09 |
55 |
Version for Release 11 |
10.1.0 |
11.0.0 |
|||
|
2013-08 |
59 |
GP-130857 |
0076 |
3 |
TCRT: Introduction of ER-GSM band |
11.0.0 |
12.0.0 |
|
2013-08 |
59 |
GP-130892 |
0077 |
3 |
Introduction of VAMOS III MS |
11.0.0 |
12.0.0 |
|
2014-11 |
64 |
GP-140945 |
0078 |
4 |
Introduction of extended TSC sets |
12.0.0 |
12.1.0 |
|
2015-11 |
68 |
GP-151219 |
0079 |
4 |
Introduction of EC-EGPRS, Multiple access and timeslot structure |
12.1.0 |
13.0.0 |
|
2015-11 |
68 |
GP-151220 |
0080 |
4 |
Introduction of EC-EGPRS, Coding interleaving and performance |
12.1.0 |
13.0.0 |
|
2016-02 |
69 |
GP-160185 |
0081 |
2 |
Introduction of EC-EGPRS, New MS power class |
13.0.0 |
13.1.0 |
|
2016-02 |
69 |
GP-160158 |
0082 |
1 |
Miscellaneous corrections to EC-EGPRS |
13.0.0 |
13.1.0 |
|
Change history |
|||||||
|
Date |
Meeting |
TDoc |
CR |
Rev |
Cat |
Subject/Comment |
New version |
|
2016-05 |
RP-70 |
GP-160463 |
0085 |
2 |
B |
Introduction of Radio Frequency Colour Code, clarifications and miscellaneous corrections to EC-GSM-IoT (including name change) |
13.2.0 |
|
2016-05 |
RP-70 |
GP-160450 |
0086 |
1 |
C |
Energy Efficient EC-CCCH/D Operation |
13.2.0 |
|
2016-05 |
RP-70 |
GP-160466 |
0089 |
– |
B |
Introduction of Radio Frequency Colour Code for PEO |
13.2.0 |
|
2016-09 |
RP-73 |
RP-161392 |
0090 |
2 |
F |
Corrections to EC-GSM-IoT |
13.3.0 |
|
2016-09 |
RP-73 |
RP-161393 |
0091 |
2 |
F |
Clarification of PEO Code Point Usage |
13.3.0 |
|
2016-09 |
RP-73 |
Editorial corrections |
13.3.1 |
||||
|
2016-12 |
RP-74 |
RP-162070 |
0092 |
– |
F |
Miscellaneous corrections to EC-GSM-IoT |
13.4.0 |
|
2016-12 |
RP-74 |
RP-162070 |
0094 |
1 |
F |
Introduction of performance for EC-GSM-IoT |
13.4.0 |
|
2016-12 |
RP-74 |
RP-162066 |
0093 |
– |
B |
Introduction of Alternative Mappings for Higher Coverage Classes with 2 PDCHs |
14.0.0 |
|
2017-03 |
RP-75 |
RP-170061 |
0095 |
– |
B |
Introduction of compact burst mapping |
14.1.0 |
|
2017-03 |
RP-75 |
RP-170060 |
0096 |
3 |
B |
Introduction of Extended Access Burst for connectionless Multilateration Positioning |
14.1.0 |
|
2017-06 |
RP-76 |
RP-170924 |
0097 |
5 |
B |
Introduction of uplink coverage class CC5 for UL MCL improvement |
14.2.0 |
|
2018-06 |
RP-80 |
– |
– |
– |
– |
Version for Release 15 |
15.0.0 |
|
2018-09 |
RP-81 |
RP-181593 |
0099 |
– |
B |
Introduction of EC-PICH |
15.1.0 |
|
2020-07 |
RP-88e |
– |
– |
– |
– |
Upgrade to Rel-16 version without technical change |
16.0.0 |
|
2022-03 |
RP-95e |
– |
– |
– |
– |
Upgrade to Rel-17 version without technical change |
17.0.0 |
-
One symbol is one to five bits depending on the modulation used: GMSK, QPSK, 8PSK, 16QAM and 32 QAM. ↑