Feature Group Indicators (FGI bits) in LTE – Rel. 8, Rel. 9 and Rel. 10

Future Network Optimization, LTE, TDD LTE, Tech Fundas, Voice Services, VoLTE

Feature Group Indicators (FGI bits)

Feature Group Indicator (FGI) is a special Information Element (IE) within UE Capability Information message. The parameters other than FGI in UE Capability Information message provides information about physical layer capability e.g. UE-Category, supported Bands, Carrier Aggregation band combination etc. Feature Group Indicator provides information about radio protocol aspects.

FGI information is used by eNodeB or MME before they set up any procedure for a specific UE. This helps the eNodeB and MME to avoid to direct UE to do something that is not supported.

FGI information is very important for troubleshooting tools for test engineers while debugging an issue. If some UE fails in some procedure like attach, Handover, a specific type of measurement, reconfiguration etc., it would be a good practice to check FGI information from UE and see if the feature or procedure is supported by it.

Example of FGI

RRC featureGroupIndicators = ‘11111110 00001101 11011000 10000000’

The Indexing starts from index 1, which is the leftmost bit in the field. Index 1-32 is for release 8, Index from 33-64 is for release 9 and Index from 101-132 is for release 10.

The meaning of each bit field in FGI is defined as follows in 3GPP specification 36.331.

  • 36.331-Annex B Table B.1-1: Definitions of feature group indicators Release 8(1-32 Bits Index)
  • 36.331-Annex B Table B.1-1a: Definitions of feature group indicators added for Release 9
  • 36.331-Annex C Table C.1-1: Definitions of feature group indicators added for Release 10

36.331-Annex B Table B.1-1

Bit Definition Note FDD/TDD
1
  • Intra-subframe frequency hopping for PUSCH scheduled by UL grant
  • DCI format 3a (TPC commands for PUCCH and PUSCH with single bit power adjustments)
  • Aperiodic CQI/PMI/RI reporting on PUSCH: Mode 2-0 – UE selected subband CQI without PMI
  • Aperiodic CQI/PMI/RI reporting on PUSCH: Mode 2-2 – UE selected subband CQI with multiple PMI
Yes
2
  • Simultaneous CQI and ACK/NACK on PUCCH, i.e. PUCCH format 2a and 2b
  • Absolute TPC command for PUSCH
  • Resource allocation type 1 for PDSCH

Periodic CQI/PMI/RI reporting on PUCCH :

  • Mode 2-0 = UE selected subband CQI without PMI
  • Mode 2-1 = UE selected subband CQI with single PMI
Yes
3
  • 5 bit RLC UM SN
  • 7 bit PDCP SN
VoLTE Bit 7 = 1 No
4 Short DRX cycle Bit 5 = 1 Yes
5 Long DRX cycle, DRX command MAC control element No
6 Prioritised bit rate No
7 RLC UM VoLTE No
8
  • EUTRA RRC_CONNECTED to UTRA FDD or UTRA TDD CELL_DCH PS handover, if the UE supports either only UTRAN FDD or only UTRAN TDD
  • EUTRA RRC_CONNECTED to UTRA FDD CELL_DCH PS handover, if the UE supports both UTRAN FDD and UTRAN TDD
Bit 22 = 1 Yes
9 EUTRA RRC_CONNECTED to GERAN GSM_Dedicated handover SRVCC Bit 23 = 1 Yes
10 EUTRA RRC_CONNECTED to GERAN (Packet_) Idle by Cell Change Order (CCO),
without or with NACC (Network Assisted Cell Change)
Yes
11 EUTRA RRC_CONNECTED to CDMA2000 1xRTT CS Active handover SRVCC Bit 24 = 1 Yes
12 EUTRA RRC_CONNECTED to CDMA2000 HRPD Active handover Bit 26 = 1 Yes
13 Inter-frequency handover within FDD or TDD Bit 25 = 1 No
14 Event measurement reporting A4 and A5 No
15 Inter RAT Event B1 :

  • UTRAN FDD or UTRAN TDD, if the UE supports either only UTRAN FDD or only UTRAN TDD and has set bit number 22 to 1
  • UTRAN FDD or UTRAN TDD, if the UE supports both UTRAN FDD and UTRAN TDD and has set bit number 22 or 39 to 1, respectively
  • GERAN, 1xRTT or HRPD, if the UE has set bit number 23, 24 or 26 to 1, respectively
UE has set at least one of the bit number 22, 23, 24, 26 or 39 = 1 Yes
16 Periodical measurement, reportStrongestCells :

  • Intra-frequency
  • Inter-frequency, if Bit 25=1
  • Inter-RAT UTRAN FDD or UTRAN TDD, if the UE supports either only UTRAN FDD or only UTRAN TDD and has set bit number 22 to 1
  • Inter-RAT UTRAN FDD or UTRAN TDD, if the UE supports both UTRAN FDD and UTRAN TDD and has set bit number 22 or 39 to 1, respectively
  • Inter-RAT GERAN, 1xRTT or HRPD, if the UE has set bit number 23, 24 or 26 to 1, respectively
No
17 Intra-frequency ANR features
periodical measurement, reportStrongestCells and reportCGI
Bit 5 = 1 No
18 Inter-frequency ANR features
periodical measurement, reportStrongestCells and reportCGI
Bit 13 = 1 No
19 Inter-RAT ANR features, periodical measurement :

  • reportStrongestCells for GERAN, if bit 23=1
  • reportStrongestCellsForSON for UTRAN FDD or UTRAN TDD, if the UE supports either only UTRAN FDD or only UTRAN TDD and has set bit number 22 to 1
  • reportStrongestCellsForSON for UTRAN FDD or UTRAN TDD, if the UE supports both UTRAN FDD and UTRAN TDD and has set bit number 22 or 39 to 1, respectively
  • reportStrongestCellsForSON for 1xRTT or HRPD, if the UE has set bit number 24 or 26 to 1, respectively
  • reportCGI for UTRAN FDD or UTRAN TDD, if the UE supports either only UTRAN FDD or only UTRANTDD and has set bit number 22 to 1
  • reportCGI for UTRAN FDD or UTRAN TDD, if the UE supports both UTRAN FDD and UTRAN TDD and has set bit number 22 or 39 to 1, respectively
  • reportCGI for GERAN1xRTT or HRPD, if the UE has set bit number 23, 24 or 26 to 1, respectively
Bit 5
At least one of the bit number 22, 23, 24 or 26 = 1
Yes
20 SRB1 and SRB2 for DCCH +

  • if Bit 7 == 0 : 8x AM DRB
  • if Bit 7 == 1 : 8x AM DRB, (5x AM DRB + 3x UM DRB)
No
21
  • Predefineintra– and inter-subframe frequency hopping for PUSCH with N_sb > 1
  • Predefined inter-subframe frequency hopping for PUSCH with N_sb > 1
No
22
  • UTRAN FDD or UTRAN TDD measurements, reporting and measurement reporting  event B2 in E-UTRA connected mode, if the UE supports either only UTRAN FDD or only UTRAN TDD
  • UTRAN FDD measurements, reporting and measurement reporting event B2 in E-UTRA connected mode, if the UE supports both UTRAN FDD and UTRAN TDD
Yes
23 GERAN measurements, event B2 Yes
24 1xRTT measurements, event B2 Yes
25 Inter-frequency measurements and reporting in E-UTRA connected mode No
26 HRPD measurements, reporting and measurement reporting event B2 in E-UTRA connected mode Yes
27
  • EUTRA RRC_CONNECTED to UTRA FDD or UTRA TDD CELL_DCH CS handover, if the UE supports either only UTRAN FDD or only UTRAN TDD
  • EUTRA RRC_CONNECTED to UTRA FDD CELL_DCH CS handover, if the UE supports both UTRAN FDD and UTRAN TDD
SRVCC Bit 13 = 1 Yes
28 TTI bundling Yes
29 Semi-Persistent Scheduling (SPS) Yes
30 Handover between FDD and TDD Bit 13 = 1 No
31 UE supports cells broadcasting Multi Frequency Band Information (MFBI) No
32  Undefined

36.331-Annex B Table B.1-1a

Bit Definition Note FDD/TDD
33 Inter-RAT ANR for UTRAN FDD
periodical measurement, reportStrongestCellsForSON, reportCGI
Bit 5 & Bit 22 = 1 Yes
34 Inter-RAT ANR for GERAN
periodical measurement, reportStrongestCellsForSON, reportCGI
Bit 5 & Bit 23 = 1 Yes
35 Inter-RAT ANR for 1xRTT
periodical measurement, reportStrongestCellsForSON, reportCGI
Bit 5 & Bit 24 = 1 Yes
36 Inter-RAT ANR for HRPD
periodical measurement, reportStrongestCellsForSON, reportCGI
Bit 5 & Bit 26 = 1 Yes
37 Inter-RAT ANR for UTRAN TDD
periodical measurement, reportStrongestCellsForSON, reportCGI
Bit 5 & Bit 39 = 1 Yes
38 EUTRA RRC_CONNECTED to UTRA TDD CELL_DCH PS handover
if the UE supports both UTRAN FDD and UTRAN TDD
Bit 39 = 1 Yes
39 UTRAN TDD measurements, reporting event B2 in E-UTRA connected mode
if the UE supports both UTRAN FDD and UTRAN TDD
Yes
40 EUTRA RRC_CONNECTED to UTRA TDD CELL_DCH CS handover
if the UE supports both UTRAN FDD and UTRAN TDD
SRVCC Bit 38 = 1 Yes
41 Measurement reporting event B1 for UTRAN FDD,
if the UE supports UTRAN FDD and has set bit number 22 to 1
Yes
42 DCI format 3a (TPC commands for PUCCH and PUSCH with single bit power adjustments)
43  Undefined
44  Undefined
45  Undefined
46  Undefined
47  Undefined
48  Undefined
49  Undefined
50  Undefined
51  Undefined
52  Undefined
53  Undefined
54  Undefined
55  Undefined
56  Undefined
57  Undefined
58  Undefined
59  Undefined
60  Undefined
61  Undefined
62  Undefined
63  Undefined
64  Undefined

36.331-Annex C Table C.1-1

Bit

Definition

Note

FDD/TDD
101 DMRS with OCC (orthogonal cover code) and SGH (sequence group hopping) disabling
  •  If the UE supports two or more layers for spatial multiplexing in UL, this bit shall be set to 1
  • If a category 0 UE does not support this feature, this bit shall be set to 0
No
102 Trigger type 1 SRS (aperiodic SRS) transmission (Up to X ports)
X = number of supported layers on given band
Yes
103 PDSCH transmission mode 9 when up to 4 CSI reference signal ports are configured Category 8 UEs Yes
104 PDSCH transmission mode 9 for TDD when 8 CSI reference signal ports are configured Category 8 UEs supporting TDD No
105 Periodic CQI/PMI/RI reporting on PUCCH :

  • Mode 2-0 = UE selected subband CQI without PMI, when PDSCH transmission mode 9 is configured
  • Mode 2-1 = UE selected subband CQI with single PMI, when PDSCH transmission mode 9 and up to 4 CSI reference signal ports are configured
Bit 2 & Bit 103 = 1 Yes
106 Periodic CQI/PMI/RI/PTI reporting on PUCCH :

  • Mode 2-1 = UE selected subband CQI with single PMI, when PDSCH transmission mode 9 and 8 CSI reference signal ports are configured
  • TDD : bit 104 = 1
  • FDD : tm9-With-8Tx-FDD-r10 supported and Bit 2 = 1
Yes
107 Aperiodic CQI/PMI/RI reporting on PUSCH :

  • Mode 2-0 = UE selected subband CQI without PMI, when PDSCH transmission mode 9 is configured
  • Mode 2-2 = UE selected subband CQI with multiple PMI, when PDSCH transmission mode 9 and up to 4 CSI reference signal ports are configured
Bit 1 & Bit 103 = 1 Yes
108 Aperiodic CQI/PMI/RI reporting on PUSCH :

  • Mode 2-2 = UE selected subband CQI with multiple PMI, when PDSCH transmission mode 9 and 8 CSI reference signal ports are configured
  • TDD : bit 104 = 1
  • FDD : tm9-With-8Tx-FDD-r10 supported and Bit 1 = 1
Yes
109 Periodic CQI/PMI/RI reporting on PUCCH Mode 1-1, submode 1 UE supports PDSCH transmission mode 9 with 8 CSI reference signal ports Yes
110 Periodic CQI/PMI/RI reporting on PUCCH Mode 1-1, submode 2 UE supports PDSCH transmission mode 9 with 8 CSI reference signal ports Yes
111 CA : Measurement reporting trigger Event A6 UE supports carrier aggregation Yes
112 CA : SCell addition within the Handover to EUTRA procedure UE supports carrier aggregation and the Handover to EUTRA procedure Yes
113 Trigger type 0 SRS (periodic SRS) transmission on X Serving Cells
X = number of supported component carriers in a given band combination
UE supports carrier aggregation in UL Yes
114 Reporting of both UTRA CPICH RSCP and Ec/N0 in a Measurement Report Bit 22 = 1 No
115 Time domain ICIC :

  • RLM/RRM measurement subframe restriction for the serving cell
  • RRM measurement subframe restriction for neighbor cells
  • CSI measurement
Yes
116 Relative transmit phase continuity for spatial multiplexing in UL UE supports two or more layers for spatial multiplexing in UL Yes
117  Undefined
118  Undefined
119  Undefined
120  Undefined
121  Undefined
122  Undefined
123  Undefined
124  Undefined
125  Undefined
126  Undefined
127  Undefined
128  Undefined
129  Undefined
130  Undefined
131  Undefined
132  Undefined