LTE Guidelines

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Confidential and Proprietary – Qualcomm Global Services, Inc.

Restricted Distribution: Not to be distributed to anyone who is not an employee of either Qualcomm or its subsidiaries without the express approval of Qualcomm’s Configuration Management.

Not to be used, copied, reproduced, or modified in whole or in part, nor its contents revealed in any manner to others without the express written permission of Qualcomm Global Services, Inc.

Qualcomm is a trademark of QUALCOMM Incorporated, registered in the United States and other countries. All QUALCOMM Incorporated trademarks are used with permission. Other product and brand names may be trademarks or registered trademarks of their respective owners.

This technical data may be subject to U.S. and international export, re-export or transfer (“export”) laws. Diversion contrary to U.S. and international law is strictly prohibited.

Qualcomm Technologies, Inc.

LTE Parameter Setting Guidelines

80-W3835-1 Rev. A

January 2013

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80-W3835-1 Rev. A MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION 2 Confidential and Proprietary – Qualcomm Global Services, Inc.

Revision history

Revision Date Description

A January 2013 Initial release

Released - For Current Employee/Consultant Use Only

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ra-PreambleIndex ... 26 2.3.1 numberOfRA-Preambles ... 27 2.3.2 sizeOfRA-PreamblesGroupA ... 28 2.3.3 messageSizeGroupA ... 30 2.3.4 messagePowerOffsetGroupB ... 31 2.3.5 ra-PRACH-MaskIndex ... 32 2.3.6 preambleInitialReceivedTargetPower ... 33 2.3.7 powerRampingStep ... 34 2.3.8 preambleTransMax... 35 2.3.9 ra-ResponseWindowSize ... 36 2.3.10 mac-ContentionResolutionTimer ... 37 2.3.11 maxHARQ-Msg3Tx ... 38 2.3.12

3 Cell Reselection Parameter Settings ... 39

3.1 Intra-frequency Cell Reselection ... 42

Introduction ... 42

3.1.1 Q ... 44

3.1.2

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TreselectionEUTRAN ... 48

3.1.6

3.2 Inter-frequency and Inter-RAT Cell Reselection Common Parameters ... 49

Cell Reselection Priority ... 49

3.2.1

Snonintrasearch ... 50

3.2.2

Threshserving, low ... 51

3.2.3

3.3 Inter-frequency Cell Reselection ... 52

TreselectionEUTRAN ... 52

3.3.1

Equal Priority Neighbor Inter-Frequency Reselection ... 53

3.3.2

Higher Priority Neighbor Inter-Frequency Reselection ... 56

3.3.3

Lower Priority Neighbor Inter-Frequency Reselection ... 58

3.3.4

3.4 Inter-RAT Cell Reselection to UTRAN ... 60

Qqualmin ... 61 3.4.1 Qrxlevmin ... 62 3.4.2 TreselectionUTRA ... 63 3.4.3

Higher Priority UTRAN Neighbor ... 64

3.4.4

Lower Priority UTRAN Neighbor ... 65

3.4.5

3.5 Inter-RAT Cell Reselection from UTRAN ... 66

Spriorityserach1 ... 66 3.5.1 Spriorityserach2 ... 67 3.5.2 QrxlevminEUTRA ... 68 3.5.3 Treselection ... 69 3.5.4

Inter-RAT Scaling Factor for Treselection ... 70

3.5.5

Higher Priority E-UTRAN Neighbor ... 71

3.5.6

Lower Priority E-UTRAN Neighbor ... 72

3.5.7

3.6 Inter-RAT Cell Reselection to GERAN ... 74

Qrxlevmin ... 74

3.6.1

TreselectionGERA ... 75

3.6.2

Higher Priority GERAN Neighbor ... 76

3.6.3

Lower Priority GERAN Neighbor... 77

3.6.4

3.7 Inter-RAT Reselection from GERAN ... 78

E-UTRAN_QRXLEVMIN... 78

3.7.1

T_reselection ... 79

3.7.2

Higher Priority E-UTRAN Neighbor ... 80

3.7.3

Lower Priority E-UTRAN Neighbor ... 81

3.7.4

3.8 Inter-RAT Cell Reselection to CDMA2000 ... 84

Higher Priority CDMA2000 Neighbor ... 84

3.8.1

Lower Priority CDMA2000 Neighbor ... 85

3.8.2

3.9 Reselection Mobility States ... 87

TCRmax ... 88 3.9.1 TCRmaxHyst ... 89 3.9.2 NCR_M ... 90 3.9.3 NCR_H ... 91 3.9.4

Qhyst Speed Dependant Scaling Factor: sf-High ... 92

3.9.5

Qhyst Speed Dependant Scaling Factor: sf-Medium ... 93

3.9.6

Treselection Speed Dependant Scaling Factor: sf-High ... 94

3.9.7

Treselection Speed Dependant Scaling Factor: sf-Medium ... 95

3.9.8

4 PHY DL Shared Channel Operation ... 96

4.1 Antenna Info ... 98

Released - For Current Employee/Consultant Use Only

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AntennaPortsCount ... 98 4.1.1 TransmissionMode ... 99 4.1.2 CodebookSubsetRestriction ... 101 4.1.3 4.2 PDSCH Configuration ... 103 ReferenceSignalPower ... 103 4.2.1 p-b ... 104 4.2.2 p-a ... 105 4.2.3

5 DL Scheduling Support – CQI/PMI/RI ... 106

5.1 Aperiodic CQI/PMI/RI Reporting on PUSCH ... 109

Cqi-ReportModeAperiodic ... 109

5.1.1

5.2 Periodic CQI/PMI/RI Reporting on PUCCH ... 111

Introduction ... 111 5.2.1 cqi-PUCCH-ResouceIndex ( 𝒏𝑷𝑼𝑪𝑪𝑯𝟐 ) ... 112 5.2.2 cqi-pmi-ConfigIndex (𝑵𝒑 and 𝑵𝑶𝑭𝑭𝑺𝑬𝑻, 𝑪𝑸𝑰) ... 113 5.2.3 cqi-FormatIndicatorPeriodic ... 115 5.2.4 ri-ConfigIndex (𝑴𝑹𝑰 and 𝑵𝑶𝑭𝑭𝑺𝑬𝑻, 𝑹𝑰) ... 117 5.2.5 simultaneousAckNackAndCQI ... 118 5.2.6 5.3 Others ... 119 nomPDSCH-RS-EPRE-Offset (𝚫𝑶𝒇𝒇𝒔𝒆𝒕) ... 119 5.3.1

6 Physical Uplink Shared Channel (PUSCH) ... 120

6.1 PUSCH frequency hopping ... 121

n-SB ... 122 6.1.1 hoppingMode... 123 6.1.2 Pusch-HoppingOffset ... 124 6.1.3 6.2 PUSCH Modulation ... 125 enable64QAM ... 127 6.2.1

6.3 PUSCH Demodulation Reference Signal ... 128

GroupHoppingEnabled ... 129 6.3.1 GroupAssignmentPUSCH (𝚫𝒔𝒔) ... 131 6.3.2 SequenceHoppingEnabled ... 132 6.3.3 CyclicShift ... 133 6.3.4

6.4 Transmission of Control Signaling on PUSCH... 135

betaOffset-ACK-Index ... 135 6.4.1 betaOffset-RI-Index ... 137 6.4.2 betaOffset-CQI-Index ... 139 6.4.3

7 PUCCH, Uplink scheduling support SRS/SR & SPS ... 141

7.1 Physical Uplink Control Channel (PUCCH) allocation ... 142

deltaPUCCH-Shift (𝚫𝒔𝒉𝒊𝒇𝒕𝑷𝑼𝑪𝑪𝑯) ... 145 7.1.1 nRB-CQI (𝑵𝑹𝑩(𝟐)) ... 146 7.1.2 nCS-AN (𝑵𝒄𝒔𝟏) ... 147 7.1.3 n1-PUCCH-AN (𝑵𝑷𝑼𝑪𝑪𝑯𝟏) ... 148 7.1.4 repetitionFactor (𝑵𝑨𝑵𝑹𝒆𝒑) ... 150 7.1.5

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SRS-SubframeConfig ... 155 7.2.2 ackNackSRS-SimultaneousTransmission ... 157 7.2.3 srs-Bandwidth ... 158 7.2.4 srs-HoppingBandwidth ... 159 7.2.5 freqDomainPosition ... 161 7.2.6 duration ... 162 7.2.7 srs-ConfigIndex ... 163 7.2.8 transmissionComb ... 165 7.2.9 cyclicShift ... 166 7.2.10 7.3 Scheduling Request ... 167 Sr-ConfigIndex ... 167 7.3.1 Sr-PUCCH-ResourceIndex ... 169 7.3.2 dsr-TransMax ... 170 7.3.3

8 Uplink Power Control Paramenter Settings ... 171

8.1 PUSCH and SRS Power Control ... 173

Introduction ... 173 8.1.1 p0-NominalPUSCH (PO_NOMINAL_PUSCH(1)) ... 176 8.1.2 p0-NominalPUSCH-Persistent (𝑷𝑶_𝑵𝑶𝑴𝑰𝑵𝑨𝑳_𝑷𝑼𝑺𝑪𝑯(𝟎)) ... 177 8.1.3 alpha ... 178 8.1.4 p0-UE-PUSCH (PO_UE_PUSCH(1)) ... 179 8.1.5 p0-UE-PUSCH-Persistent (𝑷𝑶_𝑼𝑬_𝑷𝑼𝑺𝑪𝑯(𝟎)) ... 180 8.1.6 deltaPreambleMsg3 (ΔPREAMBLE_Msg3) ... 181 8.1.7 deltaMCS-Enabled (Ks) ... 182 8.1.8 accumulationEnabled ... 183 8.1.9 filterCoefficient ... 185 8.1.10 pSRS-Offset (PSRS_OFFSET) ... 186 8.1.11

8.2 PUCCH Power Control ... 187

Introduction ... 187 8.2.1 p0-NominalPUCCH (PO_NOMINAL_PUCCH) ... 188 8.2.2 p0-UE-PUCCH (PO_UE_PUCCH) ... 189 8.2.3 deltaF-PUCCH-Format (𝚫𝑭𝑷𝑼𝑪𝑪𝑯𝑭 - Format 1)... 190 8.2.4 deltaF-PUCCH-Format (𝚫𝑭𝑷𝑼𝑪𝑪𝑯𝑭 - Format 1b) ... 191 8.2.5 deltaF-PUCCH-Format (𝚫𝑭𝑷𝑼𝑪𝑪𝑯𝑭 - Format 2)... 192 8.2.6

deltaF-PUCCH-Format (𝚫𝑭𝑷𝑼𝑪𝑪𝑯𝑭 - Format 2a) ... 193

8.2.7

deltaF-PUCCH-Format (𝚫𝑭𝑷𝑼𝑪𝑪𝑯𝑭 - Format 2b) ... 194

8.2.8

9 Handover Parameter Settings ... 195

9.1 Handover Measurement Trigger ... 199

S-Measure ... 199 9.1.1 9.2 Intra-EUTRA Handover ... 200 Intra-Frequency Handover ... 200 9.2.1 Inter-Frequency Handover ... 215 9.2.2 9.3 Inter-RAT Handover ... 229

triggerType (Measurement Report Type) ... 230

9.3.1 Purpose ... 231 9.3.2 Gap Configuration ... 232 9.3.3 Event A2 ... 233 9.3.4

Released - For Current Employee/Consultant Use Only

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Handover to UTRAN ... 239 9.3.5 Handover to GERAN ... 247 9.3.6 Handover to CDMA2000 ... 254 9.3.7

10 MAC Parameters ... 261

10.1 Introduction ... 263

10.2 RACH Related MAC Layer Parameters ... 264

ra-PreambleIndex (PRACH Preamble Index) ... 264

10.2.1 10.3 Logical Channel Related MAC Layer Parameters ... 265

Priority ... 265 10.3.1 prioritisedBitRate ... 266 10.3.2 bucketSizeDuration ... 267 10.3.3 logicalChannelGroup ... 268 10.3.4 10.4 HARQ Related MAC Layer Parameter ... 269

MaxHARQ-Tx ... 269

10.4.1 10.5 BSR Related MAC Layer Parameters ... 270

periodicBSR-Timer ... 270

10.5.1 retxBSR-Timer ... 271

10.5.2 10.6 PHR Related MAC Layer Parameters ... 272

phr-Configuration ... 272 10.6.1 periodicPHR-Timer ... 273 10.6.2 prohibitPHR-Timer ... 274 10.6.3 dl-PathLossChange ... 275 10.6.4 10.7 Connected State DRX Related MAC Parameters ... 276

DRX-Config ... 276 10.7.1 DRX-InactivityTimer ... 277 10.7.2 onDurationTimer ... 278 10.7.3 drx-RetransmissionTimer... 279 10.7.4 longDRX-CycleStartOffset ... 280 10.7.5 shortDRX ... 282 10.7.6 shortDRX-Cycle ... 283 10.7.7 drxShortCycleTimer ... 284 10.7.8 10.8 Semi Persistent Scheduling ... 285

semiPersistSchedC-RNTI ... 286 10.8.1 semiPersistSchedIntervalDL ... 287 10.8.2 numberOfConfSPS-Processes ... 288 10.8.3 n1-PUCCH-AN-PersistentList ... 289 10.8.4 semiPersistSchedIntervalUL ... 290 10.8.5 implicitReleaseAfter ... 291 10.8.6 10.9 Other MAC Layer Parameters ... 292

ttiBundling ... 292

10.9.1 timeAlignmentTimerDedicated ... 293

10.9.2

11 Radio Link Control (RLC) Parameter Settings ... 294

11.1 Acknowledged Mode (AM) ... 295

t-PollRetransmit ... 296

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t-Reordering(RLC-AM) ... 300

11.1.5

t-StatusProhibit ... 301

11.1.6

11.2 Unacknowledged Mode (UM) ... 302

sn-FieldLength (UL-UM-RLC/DL-UM-RLC) ... 302

11.2.1

t-Reordering (DL-UM-RLC) ... 304

11.2.2

12 Packet Data Convergence Protocol (PDCP) Parameter Settings ... 305

12.1 Reliable and In Sequence Delivery ... 306

discardTimer... 307 12.1.1 statusReportRequired ... 308 12.1.2 pdcp-SN-Size ... 309 12.1.3

12.2 Robust Header Compression ... 310

maxCID ... 310 12.2.1 profile0x0001 ... 311 12.2.2 profile0x0002 ... 312 12.2.3 profile0x0003 ... 313 12.2.4 profile0x0004 ... 314 12.2.5 profile0x0006 ... 315 12.2.6 profile0x0101 ... 316 12.2.7 profile0x0102 ... 317 12.2.8 profile0x0103 ... 318 12.2.9 profile0x0104 ... 319 12.2.10 12.3 Security algorithm ... 320 cipheringAlgorithm ... 320 12.3.1 integrityProtAlgorithm ... 321 12.3.2

13 RRC Timers and Parameters ... 322

13.1 Paging Timers ... 323

defaultPagingCycle... 323

13.1.1

nB ... 324

13.1.2

13.2 RRC Connection Establishment Related Timers ... 326

T300 ... 326 13.2.1 T301 ... 327 13.2.2 13.3 RLF Related Timers ... 328 T310 ... 329 13.3.1 N310 ... 330 13.3.2 N311 ... 332 13.3.3 T311 ... 333 13.3.4

13.4 Access Barring Related Timers and Parameters ... 334

T302 ... 334 13.4.1 T303 ... 335 13.4.2 T305 ... 335 13.4.3 ac-BarringTime ... 336 13.4.4 ac-BarringFactor ... 337 13.4.5 ac-BarringForSpecialAC ... 338 13.4.6

13.5 Cell Reselection and Handover Related Timers ... 339

T304 ... 339 13.5.1 T320 ... 340 13.5.2 T321 ... 341 13.5.3

Released - For Current Employee/Consultant Use Only

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Figures

Figure 3-1 Intra-Frequency Cell Reselection Example ... 43

Figure 3-2 Inter-Frequency Reselection Example (equal priority neighbor) ... 53

Figure 3-3 Inter-Frequency (or Inter-RAT) Reselection Example (Higher Priority Neighbor)... 56

Figure 3-4 Inter-Frequency (or Inter-RAT) Reselection Example (Lower Priority Neighbor) ... 58

Figure 6-1 A two-layered hopping/shifting pattern generation method ... 129

Figure 6-2 Allocation examples of two-layered frequency hopping/shifting patterns ... 130

Figure 7-1. PUCCH ... 142

Figure 7-2. Mapping of PUCCH formats to PUCCH regions. ... 143

Figure 7-3. CQI channel structure for PUCCH format 2/2a/2b with normal CP for one slot ... 143

Figure 7-4. Channel structure for HARQ ACK/NACK formats 1a/1b. More RS (Reference Signals) are used to improve coherent detection. ... 144

Figure 9-1 Event A3 entering and leaving conditions (assuming Ofn, Ocn, Ofs, Ocs = 0). ... 207

Figure 13-1 RRC Recovery after Radio Link Failure is declared ... 328

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Tables

Table 1-1. Band Classes for LTE ... 14

Table 1-2. Operating Bandwidths for LTE ... 14

Table 5-1 CQI and PMI Feedback Types for PUSCH reporting Modes ... 110

Table 5-2 Mapping of cqi-pmi-ConfigIndex to NP and NOFFSET,CQI for FDD. ... 114

Table 5-3 CQI and PMI Feedback Types for PUCCH reporting Modes ... 116

Table 5-4 Mapping of ri-ConfigIndex to MRI and NOFFSET,RI. ... 117

Table 6-1 Modulation, TBS index and redundancy version table for PUSCH ... 126

Table 6-2 Mapping of Cyclic Shift Field in DCI format 0 to ) 2 ( DMRS n _{Values. ... 134}

Table 6-3 Mapping of cyclicShift to (1) DMRS n Values. ... 134

Table 6-4 Mapping of HARQ-ACK offset values and the index signaled by higher layers ... 136

Table 6-5 Mapping of RI offset values and the index signalled by higher layers ... 138

Table 6-6 Mapping of CQI offset values and the index signalled by higher layers ... 140

Table 7-1. UCI formats for PUCCH ... 143

Table 7-2. Value of TPC command for PUCCH ... 149

Table 7-3. m_SRS,_b and

N

_b, b=0,1,2,3, values for the uplink bandwidth of

6 ≤ N

_RBUL

≤

40

. ... 153

N

40 < N

_RBUL

≤

60

. ... 153

Table 7-5. mSRS,_b and

N

b, b=0,1,2,3, values for the uplink bandwidth of

60

80

UL RB

≤

< N

. ... 154

N

80 < N

_RBUL

≤

110

. ... 154

Table 7-7. FDD sounding reference signal subframe configuration ... 156

Table 7-8. UE Specific SRS Periodicity T_SRS and Subframe Offset Configuration T_offset ... 164

Table 7-9. UE-specific SR periodicity and subframe offset configuration ... 168

Table 8-1 Mapping of TPC Command Field in DCI format 0/3 to absolute and accumulated δPUSCH values. ... 184

Table 8-2 Mapping of TPC Command Field in DCI format 3A to δPUSCH values... 184

Released - For Current Employee/Consultant Use Only

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1 Introduction

1

Chapter 1: Table of Contents

2 1.1 Purpose ... 12 3 1.2 Outline ... 12 4 1.3 General Overview ... 12 5 1.3.1 Band Classes ... 13 6 1.3.2 Operating Bandwidth ... 14 7 1.4 Notation ... 15 8 1.5 Applicable Documents ... 17 9 1.5.1 Qualcomm Documents... 17 10 1.5.2 External Specifications ... 17 11 12 13

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1.1 Purpose

1

This document provides guidelines and recommendations for setting key LTE parameters. Most of 2

these parameters are signaled to the UE either via the system information blocks, or via dedicated 3

channel signaling. The emphasis is on parameters which impact system performance and therefore 4

require optimization during trials, pre-commercial testing, and possibly during commercial operation. 5

E-UTRAN implementation-specific parameters are not covered. 6

The Appendix includes a list of abbreviations and definitions. 7

This document is based upon 3GPP Release 8 E-UTRA specifications. 8

1.2 Outline

9

A standard template is used for each parameter, or information element, as follows: 10

Definition: Brief explanation of the purpose of the parameter

11

IE Value Engineering Units

Allowed Range

Permitted range of parameter as determined by the standard, incl. step size if applicable

Permitted range in regular engineering units (e.g. dB), incl. step size if applicable

Recommended See note below See note below

Recommended Setting: A reasonably narrow range of values beyond which the parameter should not

12

normally be set. This range is the set of values over which this parameter should be optimized. The 13

range can be a single value, in which case optimization is not needed or recommended. The 14

recommended setting is given in implementation units as given in the standard and in engineering 15

units. 16

Setting Tradeoff: A brief description of the tradeoffs involved in the setting of this parameter,

17

providing an explanation of the effects of setting it “too high” and “too low”, beyond the 18

recommended range. 19

Dependencies/constraints: When applicable, an explicit reference is made to other information

20

elements whose setting may affect the setting of this parameter. 21

Traceability: List of all applicable standards, with reference to specific section number.

22

RRC Message Structure: The Information Elements (IE) and RRC messages containing the

23

parameter. 24

Notes: Any other comments and additional information about the parameter.

25

1.3 General Overview

26

In an LTE network, parameters are communicated to the UE over the air via System Information 27

Block (SIBs) and dedicated messages. 28

Upon system acquisition, which provides the UE with symbol/sub-frame and frame timing 29

information as well as physical Cell ID, the UE gathers key configuration information contained in 30

the Master Information Block (MIB) which is broadcasted on the Physical Broadcast channel (PBCH) 31

Released - For Current Employee/Consultant Use Only

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with a 40ms periodicity. After decoding PBCH/MIB, UE has knowledge about cell’s System Frame 1

Number, Cell’s DL transmission bandwidth, PHICH configuration and, indirectly, Number of 2

transmission antennas available for that cell. With this information, UE decodes PCFICH UE to 3

identify the control region used for Physical Downlink Control Channel (PDCCH) so that scheduling 4

transmissions for the Physical Downlink Shared Channel (PDSCH) can be monitored. This enables 5

the UE to read the complete System Information Blocks (SIB1 through SIB11) which, will rule UE 6

behavior while operating in the LTE network. 7

SIB1 brings information required by the UE to camp in a specific cell and the scheduling information 8

for the remaining SIBs. These are broadcast in System Information (SI) messages, each of which can 9

contain multiple SIBs. Whereas the scheduling of the MIB and SIB1 transmissions is fixed at 40 ms 10

and 80ms, respectively, the scheduling of any additional system broadcast can vary and is specified in 11

the SIB1 message along with how different SIB are multiplexed within each SI. SIBs 2 and 3 contain 12

general parameters related to access and reselection and define the configuration of the LTE cell on 13

which the UE is camped and when the UE should search for other cells for reselection. SIBs 4, 5, 6, 7 14

and 8 contain information related to neighbor cells. Information for intra- and inter-frequency 15

neighbor cells is defined in SIBs 4 and 5, respectively whilst Inter-RAT neighbor information is 16

contained in SIBs 6, 7, and 8 for UTRA, GERAN, and CDMA2000, respectively. SIB9 contains 17

information enabling the support of Home eNB, and SIBs 10 and 11 contain information related to 18

Earthquake and Tsunami warnings, as defined by 23.041 and 36.413. 19

Band Classes

1.3.1

20

The band classes for LTE are given in Table 1-1. The raster is 100 kHz. A LTE UE may support 21

operation in one or more band classes. 22

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Table 1-1. Band Classes for LTE

1

E-UTRA

Band Uplink (UL) BS receive UE transmit Downlink (DL) BS transmit UE receive Duplex Mode FUL_low – FUL_high FDL_low – FDL_high

1 1920 MHz – 1980 MHz 2110 MHz – 2170 MHz FDD 2 1850 MHz – 1910 MHz 1930 MHz – 1990 MHz FDD 3 1710 MHz – 1785 MHz 1805 MHz – 1880 MHz FDD 4 1710 MHz – 1755 MHz 2110 MHz – 2155 MHz FDD 5 824 MHz – 849 MHz 869 MHz – 894 MHz FDD 6 830 MHz – 840 MHz 875 MHz – 885 MHz FDD 7 2500 MHz – 2570 MHz 2620 MHz – 2690 MHz FDD 8 880 MHz – 915 MHz 925 MHz – 960 MHz FDD 9 1749.9 MHz – 1784.9 MHz 1844.9MHz – 1879.9 MHz FDD 10 1710 MHz – 1770 MHz 2110 MHz – 2170 MHz FDD 11 1427.9 MHz – 1452.9 MHz 1475.9MHz – 1500.9 MHz FDD 12 698 MHz – 716 MHz 728 MHz – 746 MHz FDD 13 777 MHz – 787 MHz 746 MHz – 756 MHz FDD 14 788 MHz – 798 MHz 758 MHz – 768 MHz FDD … 17 704 MHz – 716 MHz 734 MHz – 746 MHz FDD ... 33 1900 MHz – 1920 MHz 1900 MHz – 1920 MHz TDD 34 2010 MHz – 2025 MHz 2010 MHz – 2025 MHz TDD 35 1850 MHz – 1910 MHz 1850 MHz – 1910 MHz TDD 36 1930 MHz – 1990 MHz 1930 MHz – 1990 MHz TDD 37 1910 MHz – 1930 MHz 1910 MHz – 1930 MHz TDD 38 2570 MHz – 2620 MHz 2570 MHz – 2620 MHz TDD 39 1880 MHz – 1920 MHz 1880 MHz – 1920 MHz TDD 40 2300 MHz – 2400 MHz 2300 MHz – 2400 MHz TDD 2

Operating Bandwidth

1.3.2

3

Note that LTE can operate with different bandwidths on the UL and DL. Table 1-2 lists the signaling 4

variables that determine the operating bandwidths for LTE. 5

Table 1-2. Operating Bandwidths for LTE

6

Parameter Size [bits] Where Sent _ChangeRate of Neighbor Cell

Downlink bandwidth

N

_RBDL 4 Broadcast (MIB) Low Typically same

Uplink bandwidth

N

_RBUL 4 Broadcast (SIB) Low Typically same

7 8

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1.4 Notation

1

) ,

(k l Resource element with frequency-domain index k and time-domain index 2 l 3 ) ( , p l k

a Value of resource element (k,l) [for antenna portp] 4

D Matrix for supporting cyclic delay diversity

5

RA

D Density of random access opportunities per radio frame

6

0

f Carrier frequency

7

RA

f PRACH resource frequency index within the considered time domain

8

location

9

PUSCH sc

M Scheduled bandwidth for uplink transmission, expressed as a number of

10

subcarriers

11

PUSCH RB

M Scheduled bandwidth for uplink transmission, expressed as a number of

12

resource blocks

13

(q)

M_bit Number of coded bits to transmit on a physical channel [for code word q] 14

(q)

M_symb Number of modulation symbols to transmit on a physical channel [for 15

code word q] 16

layer symb

M Number of modulation symbols to transmit per layer for a physical

17

channel

18

ap symb

M Number of modulation symbols to transmit per antenna port for a

19

physical channel

20

N A constant equal to 2048 for ∆f =15kHz and 4096 for ∆f =7.5kHz 21

l

N_CP_, Downlink cyclic prefix length for OFDM symbol l in a slot 22

(1) cs

N Number of cyclic shifts used for PUCCH formats 1/1a/1b in a resource

23

block with a mix of formats 1/1a/1b and 2/2a/2b

24

(2) RB

N Bandwidth reserved for PUCCH formats 2/2a/2b, expressed in multiples

25 of RB sc N 26 PUCCH RB

N Number of resource blocks in a slot used for PUCCH transmission (set by

27

higher layers)

28

cell ID

N Physical layer cell identity

29 MBSFN ID N MBSFN area identity 30 DL RB

N Downlink bandwidth configuration, expressed in multiples of N_scRB 31

DL min, RB

N Smallest downlink bandwidth configuration, expressed in multiples of

32 RB sc N 33 DL max, RB

N Largest downlink bandwidth configuration, expressed in multiples of N_scRB 34

UL RB

N Uplink bandwidth configuration, expressed in multiples of N_scRB 35

UL min, RB

N Smallest uplink bandwidth configuration, expressed in multiples of N_scRB 36

UL max, RB

N Largest uplink bandwidth configuration, expressed in multiples of NscRB 37

DL symb

N Number of OFDM symbols in a downlink slot

38

(16)

RB sc

N Resource block size in the frequency domain, expressed as a number of

1

subcarriers

2

SP

N

Number of downlink to uplink switch points within the radio frame

3

PUCCH RS

N Number of reference symbols per slot for PUCCH

4

TA

N Timing offset between uplink and downlink radio frames at the UE,

5

expressed in units of Ts 6

offset TA

N Fixed timing advance offset, expressed in units of Ts 7

) 1 ( PUCCH

n Resource index for PUCCH formats 1/1a/1b

8

) 2 ( PUCCH

n Resource index for PUCCH formats 2/2a/2b

9

PDCCH

n Number of PDCCHs present in a subframe

10

PRB

n Physical resource block number

11

RA PRB

n

First physical resource block occupied by PRACH resource considered

12

RA offset PRB

n First physical resource block available for PRACH

13

VRB

n Virtual resource block number

14

RNTI

n Radio network temporary identifier

15

f

n System frame number

16

s

n Slot number within a radio frame

17

P Number of cell-specific antenna ports

18

p Antenna port number

19

q Code word number

20

RA

r Index for PRACH versions with same preamble format and PRACH density

21

Qm Modulation order: 2 for QPSK, 4 for 16QAM and 6 for 64QAM

22

transmissions

23

( )

t

s_l(p) Time-continuous baseband signal for antenna port p and OFDM symbol 24

l in a slot 25

0

RA

t

Radio frame indicator index of PRACH opportunity

26

1

RA

t

Half frame index of PRACH opportunity within the radio frame

27

2

RA

t

Uplink subframe number for start of PRACH opportunity within the half

28

frame

29

f

T Radio frame duration

30

s

T Basic time unit

31

slot

T Slot duration

32

W Precoding matrix for downlink spatial multiplexing

33

PRACH

β Amplitude scaling for PRACH

34

PUCCH

β Amplitude scaling for PUCCH

35

PUSCH

β Amplitude scaling for PUSCH

36

SRS

β Amplitude scaling for sounding reference symbols

37 f ∆ Subcarrier spacing 38 RA f

∆ Subcarrier spacing for the random access preamble

39

υ Number of transmission layers

40 41

42

Released - For Current Employee/Consultant Use Only

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1.5 Applicable Documents

1

Qualcomm Documents

1.5.1

2

External Specifications

1.5.2

3

[1] 36.211 Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and 4

modulation 5

[2] 36.212 Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and channel 6

coding 7

[3] 36.213 Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures 8

[4] 36.321 Evolved Universal Terrestrial Radio Access (E-UTRA); Medium Access Control 9

(MAC) protocol specification 10

[5] 36.322 Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Link Control (RLC) 11

protocol specification 12

[6] 36.323 Evolved Universal Terrestrial Radio Access (E-UTRA); Packet Data Convergence 13

Protocol (PDCP) specification 14

[7] 36.331 Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control 15

(RRC); Protocol specification 16

[8] 36.304 Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) procedures in 17

idle mode 18

19

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2 Random Access Parameters

1

Chapter 2: Table of Contents

2

2.1 Introduction ... 19 3

2.2 Physical Layer Parameters ... 19 4 2.2.1 prach-FreqOffset ... 19 5 2.2.2 prach-ConfigIndex ... 21 6 2.2.3 rootSequenceIndex... 23 7 2.2.4 NCS configuration (zeroCorrelationZoneConfig) ... 24 8 2.2.5 highSpeedFlag ... 25 9

2.3 MAC Layer Parameters ... 26 10 2.3.1 ra-PreambleIndex ... 26 11 2.3.2 numberOfRA-Preambles ... 27 12 2.3.3 sizeOfRA-PreamblesGroupA ... 28 13 2.3.4 messageSizeGroupA ... 30 14 2.3.5 messagePowerOffsetGroupB ... 31 15 2.3.6 ra-PRACH-MaskIndex ... 32 16 2.3.7 preambleInitialReceivedTargetPower ... 33 17 2.3.8 powerRampingStep ... 34 18 2.3.9 preambleTransMax ... 35 19 2.3.10 ra-ResponseWindowSize ... 36 20 2.3.11 mac-ContentionResolutionTimer ... 37 21 2.3.12 maxHARQ-Msg3Tx ... 38 22 23

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2.1 Introduction

1

The random access procedure is initiated by the UE in the following scenarios: 2

- At initial network access (UE wants to access the network in order to establish RRC 3

Connection) 4

- To send a scheduling request (in case there is no dedicated PUCCH resource configured for 5

scheduling request) 6

- To establish uplink synchronization when uplink or downlink data arrives in RRC connected 7

state and the uplink is not yet synchronized 8

- At handover (so the target eNB can measure uplink timing) 9

- After radio link failure (so the radio link can be re-established) 10

The random access procedure is triggered by the RRC layer. It involves MAC and physical layer 11

procedures and makes use of the RACH uplink transport channel mapped to the PRACH uplink 12

physical channel. Since the random access procedure carries only limited control information, there is 13

no logical channel associated to this procedure. 14

2.2 Physical Layer Parameters

15

The physical layer procedure consists of transmitting a random access preamble (msg1) on the 16

PRACH uplink channel, and receiving a random access response (msg2) on PDCCH/PDSCH. 17

On the physical layer, the PRACH uplink channel is used to send the random access preamble. 18

In the frequency domain, PRACH has 6 PRBs allocated (regardless of the system bandwidth) with a 19

position depending on the system configuration (prach-FreqOffset). In the time domain, PRACH can 20

be allocated to one or more sub-frames which depends on the system configuration (prach-21

ConfigIndex). 22

Note that the eNB is not prohibited to schedule PUSCH in the time-frequency resources allocated for 23

PRACH. 24

The random access preamble is a Zadoff-Chu sequence which makes it possible for the eNB to 25

differentiate between UEs and calculate uplink timing. Each LTE cell has a set of 64 available 26

sequences derived from the cell specific root sequence(s) (rootSequenceIndex) via cyclic shifting. A 27

group of the sequences may be reserved for contention free procedure; the rest can be used for 28

contention based random access. The contention based subset can actually be divided into two groups 29

A and B. Letting the UE chose one preamble from either group based on UL granting requirements to 30

hint the eNB about its next UL transmission requirements. 31

The random access preamble has a cyclic prefix appended. Duration of the cyclic prefix and of the 32

random access sequence is configurable. 33

prach-FreqOffset

2.2.1

34

Definition: Index of the first physical resource block (PRB) allocated for PRACH

35

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Allowed Range 0 … 𝑁_𝑅𝐵𝑈𝐿- 6 0 … 𝑁_𝑅𝐵𝑈𝐿- 6 physical resource blocks

Recommended 1 (5 MHz)

2-3 (10 MHz)

1 RB (5 MHz) 2-3 RB (10 MHz) Setting Tradeoff: n/a

1

Dependencies/Constraints: Parameter is restricted by the UL system bandwidth and PUCCH

2 configuration. 3 Traceability: TS36.211 Sect. 5.7.1 4 RRC Message Structure: 5

SIB2  RadioResourceConfigCommon  PRACH-Config  PRACH-ConfigInfoprach-6

FreqOffset. 7

Notes: In the frequency domain PRACH has always 6 PRBs allocated, regardless of the UL system

8

bandwidth (𝑁_𝑅𝐵𝑈𝐿, which is the UL system bandwidth expressed in RBs).

9 10

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prach-ConfigIndex

2.2.2

1

Definition: Determines preamble format: a) Prach cyclic prefix duration, b) preamble sequence

2

length. It also defines PRACH resource allocation in the time domain (system frame(s) and sub-3

frame(s)) 4

Allowed Range

[0 … 63] For mapping see TS36.211 Table 5.7.1-2

Preamble format: Format 0, 1, 2 or 3 System frame: Even or Any

Subframe: 1, 2, 3 or 5 selected subframes or 10 subframes

Recommended 3, 4, 5 3, 4, 5

Setting Tradeoff (see notes also notes):

5

- Preamble format: use of PRACH long cyclic prefix duration is beneficial for large cells 6

(where larger delay spreads are expected), but it may cause un-necessary overhead for a 7

small cell size deployments. Use of long preamble sequence makes access preamble reception 8

transmission more robust but occupies certain part of the consecutive subframe. 9

- PRACH resource allocation - the time domain: 10

If too few time resources are allocated, random access occasions will be infrequent, causing 11

delays in starting the random access procedure. This will result in longer call set up times 12

and handover execution times. 13

If too many time resources are allocated then there will be more chances that the PRACH 14

may collide with PUSCH, and it may lead to lower throughput. 15

- Set the PRACH Configuration Index to 3,4,5 for three cells of any site to minimize PRACH 16

to PRACH interference. The implicit corresponding preamble format is Format 0. 17 Dependencies/Constraints: None. 18 Traceability: TS36.211 Sect. 5.7.1 19 RRC Message Structure: 20

SIB2  RadioResourceConfigCommon  PRACH-Config  PRACH-ConfigInfoprach-21

ConfigIndex. 22

23

Notes: The random access preamble is composed of a cyclic prefix and a sequence part. Preamble

24

format is defining the length of each part, as described in TS36.211 Sect. 5.7.1: 25

26

Cyclic prefix Sequence

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1 Preamble Format TCP TSEQ 0 3168 TS 24576 TS 1 21024 TS 24576 TS 2 6240 TS 2x24576 TS 3 21024 TS 2x24576 TS

Where Ts = 1/(15000 x 2048) seconds is the basic time unit. 2

Note that for formats 1, 2 and 3 TCP+TSEQ > 1 ms resulting the preamble ending out of the sub-frame. 3

Also, due to propagating delay the preamble may end out of the sub-frame even for format 0 which is 4

shorter than 1 ms. It is up to the eNB implementation to handle this either via not scheduling PUSCH 5

in the consecutive subframe or to schedule PUSCH and to cope with the interference. 6

7 8

Released - For Current Employee/Consultant Use Only

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rootSequenceIndex

2.2.3

1

Definition: Index of the physical Zadoff-Chu root sequence to be used for PRACH in the cell

2

Allowed Range [0 … 837] For mapping see TS36.211 Table 5.7.2-4

Recommended Variable (Each cell should have

individual root sequence(s).

Setting Tradeoff: n/a

3 Dependencies/Constraints: None. 4 Traceability: TS36.211 Sect. 5.7.2 5 RRC Message Structure: 6

SIB2  RadioResourceConfigCommon  PRACH-Config  rootSequenceIndex 7

Notes: The RACH Root Sequence (sometimes also referred to as Logical Root Sequence Index or

8

Logical Root Sequence Number) is mapped to a Physical Root Sequence Number. Each LTE cell has 9

one root sequence assigned. 10

In order to differentiate UEs sending random access preambles at the same time, there are 64 different 11

preamble sequences available in the cell. The 64 preamble sequences are derived as cyclic shifts of 12

the Zadoff-Chu root sequence assigned to the cell. In case the 64 preambles can not be generated from 13

a single root sequence due to larger zero correlation zone setting (see parameter 14

zeroCorrelationZoneConfig), further sequences will be generated as cyclic shifts of the next root 15

sequence. The degree of orthogonalitly of preamble sequences obtained from different root sequences 16

is deteriorated. 17

The algorithm for performing the cyclic shifting is described in TS36.211 Sect. 5.7.2. It is making use 18

of two configuration parameters: Ncs and the High-Speed-Flag (for explanation of these parameters 19

see the respective section). 20

Each cell should have individual root sequence value to use the Zadoff-Chu cross-correlation 21

properties. 22

23

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N

CS

configuration (zeroCorrelationZoneConfig)

2.2.4

1

Definition: Parameter used to calculate cyclic shifts of the root Zadoff-Chu sequence in the cell

2

Allowed Range [0 … 15] For mapping see TS36.211 Table 5.7.2-2

Recommended 12*

Setting Tradeoff: For large Ncs settings, a larger cyclic shift of the ZC sequence is expected. This is

3

efficient for larger coverage and larger delay spreads, but reduces the total number of available 4

preamble sequences available in a cell and hence enforces the use of additional root sequence(s) 5

which result in the loss of degree of the orthogonality between the root sequence families. The other 6

way around, i.e the smaller Ncs, will have the contrary effect as the one described above. 7

Dependencies/Constraints: *The corresponding recommended 𝑁_𝐶𝑆 value 𝑁_𝐶𝑆 = 119 for 8

unrestricted set is based on a 15 km cell size that determines propagation delay and a maximum delay 9

spread. As results, ⌊839/119⌋ = 7 preambles per root sequence can be generated and 10 root 10

sequences are needed to produce 64 preambles. For restricted set, the corresponding recommended 11

value 𝑁_𝐶𝑆 = 119 = 158. ⌊839/158⌋ = 5 preambles per root sequence can be generated and 13 root 12

sequences are needed to produce 64 preambles. 13 14 Traceability: TS36.211 Sect. 5.7.2 15 RRC Message Structure: 16

SIB2  RadioResourceConfigCommon  PRACH-Config  PRACH-ConfigInfo  17

zeroCorrelationZoneConfig 18

Notes: The Zero Correlation Zone Config (NCS configuration) value is an index, which maps to an 19

NCS value. The mapping is different for restricted and unrestricted set (see the parameter High Speed 20

Flag). 21

The Ncs value is used to calculate the cyclic shift (CV) to generate the Zadoff-Chu preamble 22

sequence. The cyclic shift to be applied is CV = v*NCS where v = 0 … 63 describes the preamble 23

index (see description under PRACH Preamble Index). 24

Note that NCS value has an impact of the cell size. 25

26

Released - For Current Employee/Consultant Use Only

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highSpeedFlag

2.2.5

1

Definition: Defines the use of restricted sets of cyclic shifts of the Zadoff-Chu root sequence used for

2

high speed moving UEs. 3

Allowed Range BOOLEAN TRUE, FALSE

Recommended TRUE if in high-speed mobility,

FALSE otherwise

TRUE if in high-speed mobility, FALSE otherwise

Setting Tradeoff: If the parameter is set to FALSE, the unrestricted set will be used. The UE can use

4

all the sequence available every integer multiple of Ncs. However, some sequences are not optimized 5

for high Doppler shift due to high-speed mobility, and the correlation peak at eNB will reflect the 6

wrong sequence, hence the false detection cannot be avoided. 7

If the parameter is set to TRUE, the restricted set will be used. The UE can only use the specific 8

sequences which are designed for high-speed mobility. The correlation peak at eNB will be able to 9

reflect the correct sequence. 10 Dependencies/Constraints: None. 11 Traceability: TS36.211 Sect. 5.7.2 12 RRC Message Structure: 13

SIB2  RadioResourceConfigCommon  PRACH-Config  PRACH-ConfigInfo  14

highSpeedFlag 15

Notes: Setting this parameter to TRUE will result in the use of restricted sets when calculating cyclic

16

shifted sequences. The use of restricted set is optimized for high speed mobility cases with relatively 17

large Doppler shift. 18

If the parameter is set to FALSE, unrestricted set will be used. Also please note that 19

- For unrestricted set, the UE basically can use the any sequence every integer multiples of 20

Ncs. 21

- For restricted set, the UE can only use some specific sequences which can compensate the 22

high Doppler shit in high-speed mobility wireless channel. Otherwise, the correlation peak 23

will reflect the wrong sequence and hence a false detection will happen. 24

25

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2.3 MAC Layer Parameters

1

In general, the MAC layer is the one controlling the random access procedure. 2

There are two types of random access procedures: contention based and contention free. 3

In the contention based case the UE is using a randomly chosen preamble index; hence there is a 4

possible collision situation when multiple UEs attempt to use the same index at the same time (i.e. in 5

the same sub-frame). When this occurs, it needs to be resolved by the so called contention resolution 6

procedure. 7

In the contention free case the UE gets a preamble ID assigned by the network. 8

The contention based procedure is used in all cases except handover, where the contention free 9

procedure may be used instead. 10

ra-PreambleIndex

2.3.1

11

Definition: PRACH preamble index value, optionally signaled to the UE at handover for contention

12

free random access to target eNB 13

Allowed Range [0 … 63] 0 … 63

Recommended Recommended for contention-free

handover.

Setting Tradeoff: The parameter value has no significance. However, using it is recommended in

14

order to have shorter interruption at handover when contention-free procedure is enabled. Please note 15

that a number of preamble indexes from the 64 possible are reserved for contention free or dedicated 16

access. 17

Dependencies/Constraints: The value 0 shall not be used (TS36.321 Sect. 5.1.2). Value has to be

18

larger than numberOfRA-Preambles (i.e. out of the non-dedicated preambles pool). 19

Traceability: TS36.321 Sect. 5.1.1 and 5.1.2; TS36.331 Sect. 6.3.2

20

RRC Message Structure:

21

RRCConnectionReconfiguration  MobilityControlInfo  rach-ConfigDedicated  ra-22

PreambleIndex 23

Notes: When triggering handover the network may signal to the UE the PRACH preamble index and

24

the PRACH mask index. In this case the UE MAC layer will trigger a contention free random access 25

procedure using the received preamble index and mask. 26

If the preamble index or the mask index is absent (or the preamble index is 0), a contention based 27

procedure is initiated (which requires more time to complete). For this case the UE MAC will 28

randomly choose a preamble index from a given pool and will set the mask index to zero. 29

[See also notes numberOfRA-Preambles sizeOfRA-PreamblesGroupA and messageSizeGroupA] 30

Released - For Current Employee/Consultant Use Only

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numberOfRA-Preambles

2.3.2

1

Definition: Number of contention-based random access preambles available in the cell

2

Allowed Range [n4, n8, n12, … n64] 4, 8, 12 … 64 Recommended 64 if only Contention-Based RACH supported 40 – 56 if Contention-Free RACH supported

64 if only Contention-Based RACH supported 40 – 56 if Contention-Free RACH supported

Setting Tradeoff: Too small setting results in low number of contention-based preambles and

3

increases the collision probability for contention based procedure, resulting in longer random access 4

procedure duration. 5

Too high setting results in low number of contention-free preambles and hence may delay handovers 6

into the cell. 7

Dependencies/Constraints: Parameter cannot be set to 64 if contention free random access

8

procedure is used in the network 9

numberOfRA-Preambles shall not be smaller than sizeOfRA-PreamblesGroupA 10

Traceability: TS36.321 Sect. 5.1.1; 36.331 Sect. 6.3.2

11

12

SIB2  RadioResourceConfigCommon  RACH-ConfigCommon preambleInfo  13

numberOfRA-Preambles 14

Notes: This parameter defines how many out of the 64 available preambles are non-dedicated. One

15

out of these non-dedicated preambles shall be randomly chosen by the UE MAC layer in case of 16

contention-based random access procedure (i.e. when Random Access Preamble Index is not provided 17

by the network). 18

The remaining preambles (if any) are the dedicated ones which are used for contention free procedure 19

(i.e. they could be explicitly assigned by the network). 20

[See notes under sizeOfRA-PreamblesGroupA] 21

Please note that If contention-free handover is supported, this value should be function of handover 22

traffic and can be started with 56 (8 for contention-free handover) and moving lower to 40 based on 23

handover load. 24

25

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sizeOfRA-PreamblesGroupA

2.3.3

1

Definition: Number of preambles in random access preambles group A

2

Allowed Range [n4, n8, n12, … n60] 4, 8, 12, … 60

Recommended

Implementation dependent.

- If the uplink resource allocation after PRACH is to be optimized, then we need to configure this parameter.

- It depends on the statistic of the first TB size after the successful RACH procedure.

Setting Tradeoff: If this parameter is not configured, then eNodeB does not have enough information

3

for uplink resource allocation after successful RACH. So a general uplink grant is allocated. 4

If this parameter is configured, then eNodeB will be able to distinguish the size of the uplink grant 5

requested by the UE after the successful RACH procedure. 6

Dependencies/Constraints: sizeOfRA-PreamblesGroupA shall be smaller than

numberOfRA-7

Preambles 8

9

10

SIB2  RadioResourceConfigCommon  RACH-ConfigCommon  11

preambleInfo  preamblesGroupAConfig  sizeOfRA-PreamblesGroupA 12

Notes:

13

This parameter should be optimized together with messageSizeGroupA and 14

messagePowerOffsetGroupB. 15

This Parameter is optional. If it is not signaled, then sizeOfRA-PreamblesGroupA is equal to 16

numberOfRA-Preambles 17

Contention-based random access preambles (see numberOfRA-Preambles) are divided into two 18

groups: group A and B as illustrated below: 19 20 21 22 23 24 25 26

Released - For Current Employee/Consultant Use Only

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Non-dedicated preambles Dedicated preambles

Preambles group A Preambles group B

Preamble Index 0 1 2 … … 63

sizeOfRA-PreamblesGroupA

numberOfRA-Preambles

Note that if sizeOfRA-PreamblesGroupA is equal to numberOfRA-Preambles then there is no 1

preambles group B. 2

If numberOfRA-Preambles is set to 64 then there are no dedicated preambles. 3

Regarding the selection between groups A and B see notes under messageSizeGroupA 4

[See also notes under Number of Random Access Preambles]. 5

6

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messageSizeGroupA

2.3.4

1

Definition: Maximum message size when preambles group A shall be used

2

Allowed Range b56, b144, b208, b256 56 bits, 144 bits, 208 bits, 256 bits

Recommended

Setting Tradeoff: Too small setting results in selecting group B, and hence allocating un-necessary

3

large grant even for small msg3. 4

Too high setting will result in selecting group A, and hence allocating small grant for large msg3. 5

Dependencies/Constraints: The sizeOfRA-PreamblesGroupA has to be also present

6

7

8

preambleInfo  preamblesGroupAConfig  messageSizeGroupA 10

Notes:

11

This parameter should be optimized together with sizeOfRA-PreamblesGroupA and 12

messagePowerOffsetGroupB. 13

The parameter messageSizeGroupA together with messagePowerOffsetGroupB defines the threshold 14

for preambles group selection. Preambles group A always exists. Preambles group B is optional, and 15

it shall be used by UEs which intend to send larger size msg3 (RRC Connection Request). This 16

separation gives the possibility to the eNB to assign different grant for msg3 transmission depending 17

on the expected msg3 size. 18

The selection rules are the following: 19

Preambles group B shall be used by the UE if: 20

1.) Preambles group B exists 21

and 22

2.) msg3 size (including data + MAC header + eventual MAC control elements) is greater 23

than messageSizeGroupA 24

and 25

3.) If messagePowerOffsetGroupB < PCMAX – preambleInitialReceivedTargetPower – 26

deltaPreambleMsg3 – PL 27

(i.e. messagePowerOffsetGroupB < power headroom for msg3 transmission) 28

Otherwise preambles group A shall be used. 29

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messagePowerOffsetGroupB

2.3.5

1

Definition: Minimum UE power headroom where preambles group B may be used

2

Allowed Range minusinfinity, dB0, dB5, dB8, dB10, dB12,

dB15, dB18

-∞, 0dB, 5dB, 8dB, …

Recommended

Setting Tradeoff: If parameter is too low then a UE with small power headroom (i.e. in far cell

3

scenario) may still select group B and hence gets un-necessary large grant (which may not be able to 4

use anyway) 5

If parameter is set to too high then a UE may be un-necessary prevented from selecting group B and 6

hence it has to work with smaller grant. 7

Dependencies/Constraints: Values of preambleInitialReceivedTargetPower and deltaPreambleMsg3

8

has to be taken into account 9

10

11

preambleInfo  preamblesGroupAConfig  messagePowerOffsetGroupB 13

Notes: Parameter defines the threshold for preambles group selection. See notes under

14

messageSizeGroupA. 15

16 17

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ra-PRACH-MaskIndex

2.3.6

1

Definition: PRACH mask index defines the allowed preamble transmission occasions out of the ones

2

available in the system. It is optionally signaled to the UE at handover or by PDCCH order. 3

Allowed Range

[0 … 15] PRACH Resource Index:

- All - 0 - 1 - 2 - … - 9 - Every Even - Every Odd

(For mapping see TS36.321 Table 7.3-1)

Recommended

Set it to nonzero if access load is high

Setting Tradeoff: If the parameter is set to non-zero value, the eNodeB will apply the additional

4

constraint in which subframe the UE can send the PRACH during the handover or through PDCCH 5

order. This additional constraint is applied based on the subframes defined by prach-ConfigIndex. As 6

such the chances of collision can be reduced in loaded network. If the parameter is set to zero, there 7

is no additional constraint for PRACH. 8

Dependencies/Constraints:

9

- Values 13 and above are “reserved” 10

- PRACH Resource Index shall not be greater than the number of preamble occasions 11

configured in the system (see PRACH Configuration Index) 12

Traceability: TS36.211 Sect. 5.7.1; TS36.321 Sect. 5.1.1; TS36.331 Sect. 6.3.2

13

14

RRCConnectionReconfiguration  MobilityControlInfo  RACH-ConfigDedicated  ra-PRACH-15

MaskIndex 16

Notes: The PRACH mask index maps to a PRACH resource index as per TS36.321 Table 7.3-1.

17

The PRACH resource index is a mask to select a sub-set of the PRACH occasions available in the 18

system. E.g. let’s assume that sub-frames 1, 4 and 7 are configured in the system as PRACH resources 19

(PRACH configuration index = 9). If PRACH mask index = 3 is signaled, this maps to PRACH 20

resource index 2 (see table above), which selects the 3rd PRACH occasion, i.e. sub-frame 7. Hence in 21

this example the UE has to use sub-frame 7 for PRACH preamble transmission. 22

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preambleInitialReceivedTargetPower

2.3.7

1

Definition: Expected received power at the eNB for the first random access preamble

2

Allowed Range [dBm-120, dBm-118, … dBm-90] -120dBm, -118dBm, … -90 dBm

Recommended dBm-104 to dBm-108

(eNodeB implementation dependent)

-104.. -108 dBm

Setting Tradeoff: Too low setting may result in missed preamble reception(s) and hence longer

3

duration of the random access procedure. Too high setting creates un-necessary interference for 4

eventual PUSCH resources overlapping with PRACH resources. 5

Dependencies/Constraints: Has to be set according to eNB receiver characteristics (sensitivity,

6

dynamic range) 7

Traceability: TS36.213 Sect. 6.1; 36.331 Sect. 6.3.2

8

9

SIB2  RadioResourceConfigCommon  RACH-ConfigCommon  powerRampingParameters  10

preambleInitialReceivedTargetPower 11

Notes: Transmit power for the initial preamble will be calculated the following way:

12

PPRACH [dBm] = min {PCMAX, preambleInitialReceivedTargetPower + PL} 13

where 14

PCMAX is the configured maximum UE transmit power (TS36.101 Sec. 6.2.5) in dBm 15

preambleInitialReceivedTargetPower is in dBm 16

PL is the calculated downlink path loss estimate in dB 17

Also please note that Ideally, the value of preambleInitialReceivedTargetPower should be derived as -18

174 + 10Log(RACH BW) + eNodeB NF + RACH C/I. The eNodeB NF and RACH C/I may depend 19

on eNodeB implementation. The current recommended value may need to be revisited if a large 20

number of Preambles are sent by UE at cell edge. 21

22

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powerRampingStep

2.3.8

1

Definition: Step to increase transmit power for preamble transmission repetitions

2

Allowed Range [dB0, dB2, dB4, dB6] 0dB, 2dB, 4dB, 6dB

Recommended dB2 2 dB

Setting Tradeoff: Too small value results in higher number of PRACH retransmissions hence in

3

longer network access time. Too high value results in un-necessarily high preamble transmit power 4

causing un-necessary interference. 5

Dependencies/Constraints: None.

6

Traceability: TS36.213 Sect. 6.1; 36.331 Sect. 6.3.2

7

8

SIB2  RadioResourceConfigCommon  RACH-ConfigCommon  powerRampingParameters  9

powerRampingStep 10

Notes: If no response received to a PRACH preamble within the designated window (see under

11

Random Access Response Window Size), or if none of the received responses contains a preamble 12

identifier matching the transmission, the UE has to repeat the preamble transmission with increased 13

power. 14

Power of the nth preamble is calculated as the following: 15

Pn = PPRACH + (PREAMBLE_TRANSMISSION_COUNTER – 1) * powerRampingStep 16

where 17

PPRACH is the transmit power of the initial preamble in dBm 18

PREAMBLE_TRANSMISSION_COUNTER is set to 1 at the initial transmission and 19

increased by one for each further transmission 20

powerRampingStep is expressed in dB 21

The preamble retransmission procedure is repeated until a response is received or until the configured 22

maximum number of attempts is reached (see under Maximum Number of Preamble Transmission). 23

Regarding the timing of retransmissions see TS36.213 Sect. 6.1.1 24

25

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preambleTransMax

2.3.9

1

Definition: Maximum number of preamble transmissions if no response is received

2

Allowed Range [n3, n4 … n8, n10, n20, n50,

n100, n200]

3, 4, … 8, 10, 20, 50, 100, 200

Recommended n10 10

Setting Tradeoff: Too small value results in un-successful random access procedure due to not

3

enough power ramping, due to temporary RF degradation, or due to temporary overload on the eNB. 4

Too high setting results in un-necessary overload of the PRACH resources on the air interface and on 5

the eNB in the cases when eNB does not respond due to overload situation or service outage. 6

Dependencies/Constraints: Has to be aligned with timers for RRC Connection

7

(re-)establishment (T300 and T301), also considering the value of preambleTransMax and mac-8

ContentionResolutionTimer 9

10

11

ra-SupervisionInfo  preambleTransMax 13

Notes: This parameter does not limit number of RACH attempts for initial RRC Connection or HO.

14

However it does limit the number of RACH in certain RRC Connected mode cases (lack of UL grant, 15

TA expiry). Although the recommended value is in the range of 10 to 20, in a well optimized 16

network, it is expected that the RACH procedure should be successful within the first 1-3 attempts. 17

Larger number of RACH attempts needs to be investigated. 18

19

LTE Guidelines

LTE Parameter Setting Guidelines

80-W3835-1 Rev. A

January 2013

Revision history

Released - For Current Employee/Consultant Use Only

Contents

1

Introduction ... 11

2

Random Access Parameters ... 18

3

Cell Reselection Parameter Settings ... 39

4

PHY DL Shared Channel Operation ... 96

Released - For Current Employee/Consultant Use Only

5

DL Scheduling Support – CQI/PMI/RI ... 106

6

Physical Uplink Shared Channel (PUSCH) ... 120

7

PUCCH, Uplink scheduling support SRS/SR & SPS ... 141

8

Uplink Power Control Paramenter Settings ... 171

9

Handover Parameter Settings ... 195

Released - For Current Employee/Consultant Use Only

10

MAC Parameters ... 261

11

Radio Link Control (RLC) Parameter Settings ... 294

12

Packet Data Convergence Protocol (PDCP) Parameter Settings ... 305

13

RRC Timers and Parameters ... 322

Released - For Current Employee/Consultant Use Only

Figures

Tables

N

6

≤ N

≤

40

N

40

< N

≤

60

N

60

80

≤

< N

N

80

< N

≤

110

Released - For Current Employee/Consultant Use Only

1 Introduction

Chapter 1: Table of Contents

1.1 Purpose

1.2 Outline

1.3 General Overview

Released - For Current Employee/Consultant Use Only

Band Classes

1.3.1

Operating Bandwidth

1.3.2

N

N

Released - For Current Employee/Consultant Use Only

1.4 Notation

N

n

( )

t

t

t

Released - For Current Employee/Consultant Use Only