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1 NASCTN Plan [P-16-x]

2 NTIA Technical Report TR-[xx]-[xxx]

3 NIST Technical Note [xxxx]

4 AWS-3 Out of Band Emissions Measurements

5 Test and Metrology Phase II Test Plan

6 Arthur Webster NTIA/ITS

7 NASCTN Test Master

8 Sheryl Genco NIST/CTL

9 NASCTN Project Manager

10

11 Jason Coder NIST/CTL

12 Brent Bedford NTIA/ITS

13 Adam Wunderlich NIST/CTL

14 Jean-Aicard Fabien NTIA/ITS

15 Frank Sanders NTIA/ITS

16 John Ladbury NIST/CTL

17 Azizollah Kord NIST/CTL

18

19 October 11, 2016
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20 National Advanced Spectrum and Communications 

21 Test Network (NASCTN)

22 The mission of the National Advanced Spectrum and Communications Test Network (NASCTN) is to 

23 provide, through its members, robust test processes and validated measurement data necessary to 

24 develop, evaluate and deploy spectrum sharing technologies that can increase access to the spectrum by 

25 both federal agencies and non-federal spectrum users. 

26 The U.S. Department of Commerce’s National Institute of Standards and Technology (NIST) and National 

27 Telecommunications and Information Administration (NTIA) established the Center for Advanced 

28 Communications (CAC) in Boulder, Colorado, to address, among other challenges, the increasing need for 

29 spectrum sharing testing and evaluation capabilities to meet national needs. As part of CAC’s mission to 

30 provide a single focal point for engaging both industry and other government agencies on advanced 

31 communication technologies, including testing, validation, and conformity assessment, NASCTN was 

32 formed under the umbrella of the CAC. NIST hosts the NASCTN capability at the Department of 

33 Commerce Boulder Laboratories in Boulder, Colorado.

34 NASCTN is a membership organization under a charter agreement. Members 

35  Make available, in accordance with their organization’s rules policies and regulations, engineering 

36 capabilities and test facilities, with typical consideration for cost. 

37  Coordinate their efforts to identify, develop and test spectrum sharing ideas, concepts and 

38 technology to support the goal of advancing more efficient and effective spectrum sharing.

39  Make available information related to spectrum sharing, considering requirements for the protection 

40 of intellectual property, national security, and other organizational controls, and, to the maximum 

41 extent possible, allow the publication of NASCTN test results.

42  Ensure all spectrum sharing efforts are identified to other interested members.

43 Current charter members are:

44  National Telecommunications and Information Administration (NTIA)

45  National Institute of Standards and Technology (NIST)

46  Department of Defense Chief Information Officer (DoD CIO)

47
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48 NASCTN Plan [P-16-x]

49 NIST Technical Note [xxxx]

50 NTIA Technical Report TR-[xx]-[xxx]

51 AWS-3 Out of Band Emissions Measurements

52 Test and Metrology Phase II Test Plan

53 Arthur Webster

54 NTIA/ITS (Test Master)

55 Sheryl Genco

56 NIST/CTL (Project Manager)

57 Jason Coder

58 NIST/CTL

59 Brent Bedford

60 NTIA/ITS

61 Adam Wunderlich

62 NIST/CTL

63 Jean-Aicard Fabien

64 NTIA/ITS

65 John Ladbury

66 NIST/CTL

67 Frank Sanders

68 NTIA/ITS

69 Azizollah Kord

70 NIST/CTL

71

72

73

74

75

76

77

78 October 11, 2016

79
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80 Disclaimer

81 This document is disseminated by the Center for Advanced Communications/ National 

82 Advanced Spectrum and Communications Test Network in the interest of information exchange. 

83 The United States Government assumes no liability for the contents or use thereof. The United 

84 States Government does not endorse products or manufacturers. Trade or manufacturers’ names 

85 appear herein solely because they are considered essential to the objective of this report.

86
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87 Preface

88 The National Advanced Spectrum and Communications Test Network (NASCTN) provides a 

89 neutral forum for addressing spectrum-sharing challenges in an effort to accelerate the 

90 deployment of wireless technologies among commercial and federal users. NASCTN was 

91 created in 2015 and is a joint effort among the National Institute of Standards and Technology 

92 (NIST), the National Telecommunications and Information Administration (NTIA), and the 

93 United States Department of Defense (DoD).

94 NASCTN’s mission is to provide robust test processes and validated measurement data 

95 necessary to develop, evaluate and deploy spectrum sharing technologies that can increase access 

96 to the spectrum by both federal agencies and non-federal spectrum users. NASCTN is a function 

97 within the Center for Advanced Communications, a joint research effort of the NTIA and NIST.

98 Representatives from Edwards Air Force Base submitted a proposal to NASCTN to measure out 

99 of band emissions (OOBE) from LTE eNB and UE in the United States Advanced Wireless 

100 Service (AWS)-3 frequency band into adjacent L and S frequency band aeronautical mobile 

101 telemetry (AMT) systems. NASCTN formed a team to examine the proposal and discuss it with 

102 the proposer. The team decided to recommend that the proposal be adopted as a NASCTN 

103 project. The Center for Advanced Communications co-directors considered the recommendation 

104 and decided to create a new NASCTN project.

105 A Test Plan development team, composed of experienced engineers and other professionals, was 

106 formed. While working on the details of the test plan, the team performed investigations and 

107 some simplified measurements in LTE Band 3 with commercially available equipment to guide 

108 the team’s decisions. The results of that work plus the knowledge and creativity of the team 

109 members culminated in the production of this test plan.

110 The test plan is designed to yield reproducible measurements. This NASCTN effort focuses on 

111 impacts of proposed LTE activities to AMT activities in the adjacent L and S Bands. NASCTN 

112 will solicit comments about the test plan from the engineering community within federal and 

113 non-federal groups and entities.
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114 Contents

115 Disclaimer....................................................................................................................................... ii

116 Preface............................................................................................................................................iii

117 List of Figures................................................................................................................................ vi

118 List of Tables ............................................................................................................................... viii

119 Executive Summary....................................................................................................................... ix

120 1. Introduction............................................................................................................................. 11

121 1.1. Objectives....................................................................................................................... 14

122 1.2. Phase I Summary............................................................................................................ 15

123 1.3. Phase II Summary .......................................................................................................... 18

124 2. Phase II DUTs......................................................................................................................... 19

125 2.1. UEs................................................................................................................................. 19

126 2.2. eNodeB (Base Station) Hardware .................................................................................. 20

127 3. Measurement Equipment ........................................................................................................ 21

128 3.1. RF Front End/Preselector............................................................................................... 21

129 3.2. Circulators...................................................................................................................... 23

130 3.3. Spectrum Analyzer......................................................................................................... 23

131 3.4. eNodeB (Base Station) Emulator................................................................................... 24

132 4. UE Measurement Setup .......................................................................................................... 25

133 5. UE Measurement Procedure ................................................................................................... 27

134 6. eNodeB Measurement Setup................................................................................................... 28

135 7. eNodeB Measurement Procedure ........................................................................................... 29

136 8. Calibration Procedure ............................................................................................................. 31

137 9. Statistical Analysis.................................................................................................................. 32

138 9.1. Relevant Experimental Variables................................................................................... 32

139 9.2. Potential Sources of Uncertainty.................................................................................... 32

140 9.3. Analysis Plan.................................................................................................................. 33

141 9.4. Potential Confounding Factors and Their Mitigation .................................................... 34

142 10. References............................................................................................................................... 34

143 Appendix A - Phase I Measurements............................................................................................ 36

144 A.1. RF Preselector Characterization..................................................................................... 36

145 A.2. UE Measurements.......................................................................................................... 36

146 A.2.1. UE Measurement Setup .......................................................................................... 36

147 A.2.2. Phase I UE Measurement Procedure....................................................................... 42

148 A.2.3. Phase I UE Measurement Results........................................................................... 43
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149 A.2.4. Phase I UE Measurement Conclusions................................................................... 45

150 A.3. eNodeB Measurements .................................................................................................. 45

151 A.3.1. eNodeB Measurement Setup................................................................................... 46

152 A.3.2. eNodeB Measurement Procedure ........................................................................... 48

153 A.3.3. Phase I eNodeB Measurement Results................................................................... 48

154 A.3.4. Phase I eNodeB Measurement Conclusions........................................................... 49

155 A.4. References...................................................................................................................... 49

156
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157 List of Figures

158 Figure 1. Frequency bands of interest for this test........................................................................ 12

159 Figure 2. How emission spectrum measurements will be used in AWS-3 band sharing 

160 analysis studies.............................................................................................................................. 14

161 Figure 3. Conducted UE emission spectrum measurement. UE was operated at maximum 

162 power with all resource blocks occupied. The mask shown is representative of the FCC’s 

163 allowable emissions mask............................................................................................................. 16

164 Figure 4. Radiated UE emission spectrum measurement. UE was operated at maximum 

165 power with all resource blocks occupied. The mask shown is representative of the FCC’s 

166 allowable emissions mask............................................................................................................. 16

167 Figure 5. Comparison of conducted and radiated UE spectrum measurements. The mask 

168 shown is representative of the FCC’s allowable emissions mask................................................. 17

169 Figure 6. eNodeB conducted emission spectrum measurement. Transmitter operated at 

170 maximum power. The mask shown is representative of the FCC’s allowable emissions 

171 mask. ............................................................................................................................................. 17

172 Figure 7. Block diagram of RF front end needed for wide dynamic range spectrum 

173 measurements................................................................................................................................ 22

174 Figure 8. Block diagram of the E4440A digital spectrum analyzer with a stand-alone RF 

175 front end, as used for the UE and eNB spectrum measurements.................................................. 24

176 Figure 9. Block diagram of the UE emission spectrum measurement system.............................. 25

177 Figure 10. Block diagram of the eNB spectrum measurement system......................................... 29

178 Figure 11. YIG off-tuning technique that will be used for wide dynamic range eNB 

179 emission spectrum measurements. The YIG center is offset (∆f) from the measurement 

180 system’s tuned frequency up to the limit of the YIG’s 3-dB roll-off points, half of the 

181 YIG’s flat passband width. ........................................................................................................... 30

182

183 Figure A-1. Block diagram of the UE emission spectrum measurement system. ........................ 37

184 Figure A-2. The CMW-500 base station emulator (top) and one of the spectrum analyzers 

185 used to troubleshoot and verify the measurement setup (bottom). ............................................... 39

186 Figure A-3. The spectrum analyzer (bottom right), acquisition laptop (on top of the 

187 spectrum analyzer), and RF preselector (3 box stack) used for both the UE and eNodeB 

188 measurements................................................................................................................................ 40

189 Figure A-4. The UE used in Phase I measurements, shown with the hardline attached to one 

190 of the RF ports. ............................................................................................................................. 40

191 Figure A-5. The UE placed inside the small anechoic chamber during the coupled/radiated 

192 testing. The UE is placed on top of foam blocks, and appears as a silver line immediately 

193 underneath the horn antenna. ........................................................................................................ 41

194 Figure A-6. The Phase I test UE is shown with the passive coupler banded to it. ....................... 42

195 Figure A-7. Conducted UE emission spectrum measurement. UE was operated at maximum 

196 power with all resource blocks occupied. ..................................................................................... 44

197 Figure A-8. Radiated UE emission spectrum measurement. UE was operated at maximum 

198 power with all resource blocks occupied. Dashed lines show this uncertainty. ........................... 45
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199 Figure A-9. The eNodeB hardware used in Phase I. The bottom of the three units is the 

200 power supply, the middle the CPU, and the top the remote radio head........................................ 47

201 Figure A-10. eNodeB connection setup to measure downlink OOB emission............................. 47

202 Figure A-11. YIG off-tuning technique used for wide dynamic range eNB emission 

203 spectrum measurements. The YIG center is offset (∆f) from the measurement system’s 

204 tuned frequency up to the limit of the YIG’s 3-dB roll-off points, half of the YIG’s flat 

205 passband width.............................................................................................................................. 48

206 Figure A-12. eNodeB conducted emission spectrum measurement. Transmitter operated at 

207 maximum power. .......................................................................................................................... 49

208
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209 List of Tables

210 Table 1. Operating parameters of the R&S CMW-500 during UE spectrum measurements. ...... 26

211 Table 2. Measurement set for each UE......................................................................................... 27

212 Table 3. Measurement set for the eNB. ........................................................................................ 31

213

214 Table A-1. Operating parameters of the R&S CMW-500 during UE spectrum 

215 measurements................................................................................................................................ 38

216
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217 Executive Summary

218 The purpose of this NASCTN project is to establish a test methodology and measure the out of 

219 band emissions (OOBE) from LTE user equipment (UE) and evolved NodeB base station

220 (eNodeB or eNB) activities in the United States AWS-3 frequency band into the adjacent L and 

221 S frequency bands utilized by aeronautical mobile telemetry (AMT) systems. Phase I of this 

222 project is the development of a test methodology for measuring out of band emissions from 

223 AWS-3 equipment. Phase II will involve the actual measurement of out of band emissions from 

224 AWS-3 UE and eNB.

225 During Phase I, the NASCTN team performed initial investigations and measurements to inform 

226 and develop this test plan and methodology for conducting out of band emission measurements 

227 on LTE UE and eNodeBs that will operate in the United States AWS-3 band. Due to the 

228 unavailability of commercial equipment in the AWS-3 band at the beginning of this project, the 

229 Phase I measurements were performed on 3GPP Band 3 equipment. That effort informed the 

230 development of this test plan.

231 Two measurement setups and procedures are described in this test plan. The first is a setup and 

232 procedure to measure the emissions of a UE. Depending on the UE under test, either conducted 

233 emissions measurements or coupled emission measurements are performed. A base station 

234 emulator used to control the desired emissions from the UE. A spectrum analyzer is used in a 

235 stepped measurement system to measure the isolated UE emissions with peak and average 

236 detectors. The measurement bandwidths are varied from 100 kHz to 3 MHz and the number of 

237 UE transmitted resource blocks are varied from 5 to 50. This measurement procedure is expected 

238 to produce over 100 dB of measurement range in the result.

239 The second is a setup and procedure to measure the emissions of an eNB. Conducted emissions 

240 measurements are performed in a simpler measurement setup since the eNB does not require a 

241 second transceiver to be present for the test. A spectrum analyzer is used in a stepped 

242 measurement system to measure the isolated UE emissions with peak and average detectors. The 

243 measurement bandwidths are varied from 100 kHz to 3 MHz and the number of UE transmitted 

244 resource blocks are varied from 5 to 50. This measurement procedure is expected to produce 

245 over 110 dB of measurement range in the result.

246 The Appendix to this test plan provides measurement results from the OOBE testing done on the 

247 3GPP Band 3 equipment. Those results informed and validated some of the test plan’s methods.

248 The objective of Phase I was not to produce final spectrum measurements but to do simplified 

249 spectrum measurements from which to make observations and develop the test plan. None of the 

spectra shown in the appendix should be used to draw conclusions or make decisions1250 .

 

1 The purpose of the Phase II Test Plan is to define measurement methods for OOBE in AWS-3 bands (1755–1780 

MHZ uplink and 2155–2180 downlink). Because AWS-3 (3GPP Band 66) is newly licensed, equipment was not 

available for testing. To determine the test methodologies (subject of Phase I), 3GPP Band 3 (1710–1785 MHz 

uplink and 1805–1880 MHz downlink) equipment was used. See the Appendix for more details.
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251 NASCTN will next seek public comment on this test plan. In Phase II, the final test plan will be 

252 executed and measurements made on actual AWS-3 equipment. Detailed and informative spectra 

253 will be published at the end of Phase II.
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254 AWS 3 Out of Band Emissions Measurements 

255 Test and Metrology Phase II Test Plan

Arthur Webster,

2 Sheryl Genco,3

Jason Coder,

3 Brent Bedford,2 Adam Wunderlich,3

Jean-Aicard Fabien,

2 256

Frank Sanders,3John Ladbury,3 Azizollah Kord3 257

258 Abstract: Wide dynamic range emission measurements of LTE mobile phones 

259 (user equipment, or UEs) and base station hardware (eNodeBs) that will share 

260 spectrum with telemetry links in the newly available AWS-3 band U.S.

261 (designated Band 66 by 3GPP) are needed. A test plan for measuring out of band 

262 emissions is presented that ensures objective, repeatable, and reproducible 

263 measurement results. The measurement method is outlined and demonstrated for 

264 Band 3 hardware (note that the uplink for Bands 3 and 66 overlap). The test plan 

265 describes emission measurements that will be performed by NASCTN on a 

266 variety of LTE UEs and eNodeBs that will be deployed in the AWS-3 band.

267 These measurements will provide data on out of band emissions from AWS-3 

268 equipment. The data may inform interference analyses for band sharing studies, 

269 including frequency and distance separation parameters between LTE hardware 

270 and telemetry receivers, to preclude harmful interference from UEs to telemetry 

271 links when the AWS-3 band is eventually shared by these systems. 

272 Keywords: Band sharing; band sharing analysis; interference analysis; eNodeB 

273 (eNB); emission spectrum; telemetry links; user equipment (UE); AWS-3; 

274 1755-1780 MHz, 2155-2185 MHz; Band 66; aeronautical mobile telemetry 

275 (AMT); out of band emissions (OOBE); spectrum measurements.

276 1. Introduction

277 The Federal Communications Commission (FCC) has auctioned off and is issuing licenses for 

278 the introduction of new radio systems into the 1755–1780 MHz (uplink) and 2155–2180 MHz 

279 (downlink) portion of radio spectrum in the United States (commonly referred to as AWS-3 or 

280 Band 66). Out of band emissions (OOBE) from LTE devices have the potential to impact

281 operation of co-located and adjacent-band aeronautical mobile telemetry (AMT) systems that 

282 operate in the 1780–1850 MHz (L Band) and 2200–2395 MHz (S Band) frequency bands. This 

283 part of the frequency spectrum is depicted in Figure 1.

 

2 The authors are with the Institute for Telecommunication Sciences, National Telecommunications and Information 

Administration, U.S. Department of Commerce, Boulder, CO 80305.

3 The authors are with the Communications Technology Laboratory, National Institute of Standards and 

Technology, U.S. Department of Commerce, Boulder, CO 80305.
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284

285 Figure 1. Frequency bands of interest for this test.

286 A joint team of National Telecommunications and Information Administration (NTIA) and 

287 National Institute of Standards and Technology (NIST) engineers are collaborating within the 

288 National Advanced Spectrum and Communications Test Network (NASCTN) to develop a test 

289 and metrology plan suitable to ensure transparent, and reproducible measurements of AWS-3

290 OOBEs. This NASCTN team has performed initial investigations and measurements to inform 

291 the development of a test plan to use for conducting OOBE measurements on LTE User 

292 Equipment (UEs) and eNodeBs (eNBs) operating in the AWS-3 band (1755-1780 MHz uplink 

293 and 2155-2180 MHz downlink). The initial investigations and measurements are referred to as 

294 Phase I. In Phase I, the test plan was developed that is to be used for Phase II. Because the 

295 commercial equipment in the AWS-3 band was not available at the start of this effort, the Phase I

296 measurements were done on existing NIST-owned 3GPP Band 3 (1710-1785 MHz uplink and 

297 1805-1880 MHz downlink) equipment. The Phase II test plan will be executed on AWS-3

298 equipment.

299 Spectrum sharing studies require interference analyses that are based on detailed, wide dynamic 

300 range measurements of emissions from individual transmitters that are to share spectrum with 

301 other systems. Such measurements show the rate of roll-off of transmitted emissions as a 

302 function of off-tuning from transmitter center frequencies, e.g., that a transmitter’s emission 

303 levels might be reduced by 85 dB relative to the power at the fundamental when a receiver is off304 tuned from the fundamental.

305 It is sometimes suggested that emission measurements are not needed because it can be assumed 

306 that transmitters operate at their required emission mask limits. This assumption is nearly always 

307 false. Transmitter out of band (OOB) and spurious emissions are usually substantially lower than 

308 emission mask limits, often by tens of decibels. Interference studies that assume that transmitter 

309 emissions are as high as emission mask limits will therefore overestimate the power levels of 

310 most transmitters’ OOB and spurious emissions. As a result, required frequency and distance 
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311 separations needed for compatible operations between systems will also be overestimated. The 

312 only way to avoid such overestimates is to accurately measure the OOB and spurious emission 

313 levels of transmitters.

314 Regarding the new spectrum sharing that will soon begin in the 1755–1780 MHz spectrum, the 

315 incumbent systems are air-to-ground telemetry links that operate at U.S. flight-test ranges. These 

316 links use high-gain antennas typically pointed at elevation angles approaching 0 degrees due to 

317 the long slant ranges supported between the test platforms and ground stations to track airborne 

318 platforms carrying telemetry transmitters. The ground-based telemetry antennas feed the airborne 

319 platforms’ signals into ground-based telemetry receivers for recording and analysis. The new 

320 wireless broadband systems anticipated to be introduced into 1.7 GHz spectrum will almost 

321 certainly be LTE networks consisting of user devices (UEs) and base stations (eNodeBs).

322 Spectrum sharing analyses need to be performed to determined how much off-tuning (number of 

323 megahertz) and distance separation (number of kilometers) are needed between transmitters and 

324 telemetry receiver stations to avoid harmful interference to the telemetry receivers. To complete 

325 these studies, detailed, wide dynamic range emission spectrum measurements of the soon-to-be326 deployed AWS-3 LTE transmitters need to be performed. 

327 Interference analyses often require emission spectrum measurements with a dynamic range of 

328 100 dB or more. Currently available measurement instrumentation often does not achieve such

329 wide dynamic ranges. This includes swept-frequency and high-speed time-domain sampling 

330 systems. To overcome this limitation and achieve dynamic ranges of as much as 120 dB in 

331 OOBE measurements, a measurement system with the characteristics described below needs to 

332 be used. These measurements go beyond the standard 3GPP measurements as documented in 

333 3GPP TS 36.101 [7] and 3GPP TS 36.121 [8].

334 Figure 2 shows how the measurements described in this plan can be used in the overall spectrum 

335 sharing analyses for mobile-to-telemetry interference scenarios.
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336

337 Figure 2. How emission spectrum measurements will be used in AWS-3 band sharing analysis studies.

338 The measurement system requires a radio frequency (RF) front end with three major 

339 components: a variable RF attenuator, a tunable bandpass filter, and a low-noise amplifier 

340 (LNA). The RF attenuator extends the dynamic range of the measurement system, the bandpass 

341 filter rejects high-power signals when the measurement system is off-tuned from the transmitter 

342 fundamental frequency, and the LNA provides a low measurement system noise figure (high 

343 sensitivity to weak signals – typical in interference measurements) in low-power portions of the 

344 transmitter emission spectrum.

345 The final output of these OOBE measurements will be a set of emissions data for commonly 

346 deployed hardware that demonstrates the type of emissions that may be observed in the band. 

347 These emissions will be measured as close to the device as possible, so additional analysis will 

348 be required to account for the propagation environment and telemetry receiver characteristics. 

349 1.1. Objectives 

350 The objective is to develop a test plan to provide measured data showing the typical emissions 

351 from LTE UE and macro-cell eNodeB devices that will be operating in the AWS-3 band. This 
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352 document presents a test plan for achieving this objective, along with preliminary data 

353 supporting some of the test plan’s recommendations. 

354 1.2. Phase I Summary

355 During the initial planning, the test plan development team foresaw a need to determine how to 

356 configure the devices under test (DUTs) and how to configure a measurement system that will 

357 collect the emission spectra of those devices. Determining this involves research into how to

358 configure the units and how they function under various conditions. Additional research was 

359 needed to determine the measurement system configurations needed to collect the required 

360 emissions data while the DUTs were operating in various parameters and operational modes. 

361 This need was met through some initial simplified measurements and observations, referred to as 

362 Phase I. As the goal of Phase I was to demonstrate configurations of DUTs and measurement 

363 hardware, only one UE and one eNodeB were measured.

364 The goal of Phase I was not to produce final spectrum measurements but to do simplified 

365 spectrum measurements from which to make observations and to learn. None of the spectra 

366 shown in this report should be used to draw conclusions or make decisions. More detailed and 

367 informative spectra are expected to be shown in a report to be published at the end of Phase II, 

368 when actual AWS-3 hardware has been measured. The results of the measurements and 

369 observations from Phase I are presented in Appendix A.

370 The Phase I emission spectrum measurements were performed on Band 3 hardware deployed in a 

371 laboratory setting. The measurement system was connected to the UE and eNodeB (eNB) via 

hardlines4372 whenever possible. When hardline connections were not possible, short-range (several 

373 cm) radiated paths were used between a small horn and the UE in an anechoic chamber. For all 

374 of the Phase I testing, the UEs and the eNB were operated at their maximum output power levels.

375 For each test case, the DUT’s emission spectrum was measured in peak and average detection 

376 modes in bandwidths of 100 kHz, 300 kHz, 1 MHz, and 3 MHz (1 MHz will be the reference 

377 measurement bandwidth for all measurements). Emission spectra were measured as a function of 

378 the number of resource blocks (RBs) in use by the UE. The eNB spectrum was measured for 

379 three tuned frequencies: the bottom, middle, and top of the operational band.

380 All measured emission spectra are reported in terms of power relative to the power measured at 

381 the transmitters’ center frequencies (f0). These relative-power, normalized emission spectra will 

382 be used in larger spectrum compatibility studies as shown in Figure 2.

383 Phase I measurement results are shown in Figures 3 to 6. The OOBE mask is generated for the 

384 AWS 3 frequencies using the FCC equation for emission masks. In general, the Phase I 

385 measurements show that UE and eNodeB emissions fall off rapidly outside the assigned 

386 frequency band.

 

4 Testing via hardline will provide the worst case emission.
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387

388 Figure 3. Conducted UE emission spectrum measurement. UE was operated at maximum power with all resource 

389 blocks occupied. The mask shown is representative of the FCC’s allowable emissions mask.

390

391 Figure 4. Radiated UE emission spectrum measurement. UE was operated at maximum power with all resource 

392 blocks occupied. The mask shown is representative of the FCC’s allowable emissions mask.
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393

394 Figure 5. Comparison of conducted and radiated UE spectrum measurements. The mask shown is representative of 

395 the FCC’s allowable emissions mask.

396

397 Figure 6. eNodeB conducted emission spectrum measurement. Transmitter operated at maximum power. The mask 

398 shown is representative of the FCC’s allowable emissions mask.
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399 1.3. Phase II Summary

400 Phase II measurements will be performed in the same manner as Phase I measurements. The 

401 difference will be that the Phase II measurements will be performed on equipment that will be

402 deployed in the AWS-3 band.
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403 2. Phase II DUTs

404 As has been discussed in earlier sections, Phase I testing involved the use of Band 3 equipment. 

405 During Phase II, actual AWS-3 hardware will be required. However, it is impractical to test all 

406 AWS-3 UEs and eNodeBs deployed in the marketplace. Therefore, a subset of deployed 

407 equipment must be selected. 

408 During Phase I, two different Band 3 UEs were used. These were selected because they were 

409 easily available, worked in Band 3, and most importantly, provided access to their RF ports. An

410 eNodeB was examined to demonstrate the proposed test method. This eNodeB was a macro-cell 

411 design and was deployed in late 2014.

412 2.1. UEs

413 An examination of existing deployments in the current U.S. LTE bands reveals three categories 

414 of UE types: mobile phones (commonly referred to as “UEs”), tablets, and consumer premise 

415 equipment (CPE). Examples of CPE are nano/pico/femto-cell base stations that may be deployed 

416 inside a dwelling for the purpose of repeating (“boosting”) the LTE signal, and LTE routers that 

417 serve as a Wi-Fi access point and then convert the traffic to LTE. 

418 According to a study done by Ericsson [2], smartphones constitute about 75% of the North 

419 American UE deployments. Given this, the NASCTN team decided not to measure the emissions 

420 from devices other than smartphones. 

421 To select from all available UEs, we examined which UEs were most commonly sold in the U.S. 

422 (for any band/network). From the list of the most commonly sold UEs, we suggest selecting the 

423 top five and performing emissions measurements on them. Counterpoint Research [3] conducts a 

424 quarterly survey of the most commonly sold UEs by surveying mass market retailers and 

425 distributors. The disadvantage of this study is that it does not include sales through wireless 

426 carriers. Therefore, we make the assumption that the most popular phones sold through mass427 market retailers are very similar (if not identical) to those from carriers. The top five list 

428 generated from [3] is: 

429 1. Apple iPhone 6

430 2. Apple iPhone 6 Plus

431 3. Samsung Galaxy S6

432 4. Samsung Galaxy S6 Edge

433 5. Xiaomi Redmi 2

434 The first and second, and third and fourth UEs on this list are nearly identical to each other. The 

435 main difference being the display type and physical size of the UE. It is very likely that they 

436 have exactly the same RF chipsets, and thus will have very similar emissions. To augment the 

437 list, we include the sixth and seventh most popular UEs: 
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438 1. Apple iPhone 6 or 6 Plus (#2)

439 3. Samsung Galaxy S6 or S6 Edge (#4)

440 5. Xiaomi Redmi 2

441 6. Samsung Galaxy Note 4

442 7. Apple iPhone 5S

443 The disadvantage of each of these UEs is that their conducted RF ports are not accessible for 

444 conducted RF emissions measurements. Therefore, only coupled/radiated measurements are 

445 possible. The coupled/radiated measurement method is further discussed in Section 5.

446 2.2. eNodeB (Base Station) Hardware

447 For the purposes of the Phase I and II emissions measurements, we are only considering macro448 cell eNodeBs. There will almost certainly be small cell deployments in the AWS-3 band, but 

449 they will all be lower power (e.g., <1 W) and most will be deployed indoors. Short of one being 

450 deployed in the immediate vicinity of an AMT system, their emissions are not expected to be of 

451 significant concern. 

452 Though there are significantly fewer models of eNodeBs than there are UEs, it is still not 

453 practical to test all of the available models. The most popular UE manufacturers are (in no 

454 order): Nokia, Alacatel-Lucent (now owned by Nokia), Ericsson, Motorola, and Huawei. There 

455 are no market sales data available to identify which models or manufacturers are the most 

456 popular. In Phase II, an attempt can be made to obtain an eNodeB from each of these vendors. 

457 By design, all macro-cell eNodeBs will give access to their RF ports. For Phase II measurements, 

458 the conducted method described in Section 7 will be used.
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459 3. Measurement Equipment

3.1. RF Front End/Preselector5 460

461 The overall measurement technique is based on the stepped-measurement approach described in 

462 the best practices NTIA report [4]. Although [4] describes the technique as applied to 

463 measurements of radar emission spectra, the same technique works equally well for LTE-type 

464 emissions, as described for a 3.5 GHz LTE hotspot in [5].

465 Interference analyses often require emission spectrum measurements with a dynamic range of 

466 100 dB or more. Available measurement instrumentation does not achieve such wide dynamic 

467 ranges. This includes swept-frequency and high-speed time-domain sampling systems. To 

468 overcome this limitation and achieve dynamic ranges of as much as 130 dB in emission 

469 measurements, a measurement system with the characteristics described in [4] needs to be used.

470 As shown in Figure 7, the heart of this approach lies in the use of a radio frequency (RF) front 

471 end with three major components: a variable RF attenuator, a tunable bandpass filter, and a low472 noise amplifier (LNA). The RF attenuator extends the dynamic range of the measurement 

473 system, the bandpass filter rejects high-power radio power when the measurement system is off474 tuned from the radio fundamental frequency, and the LNA provides a low measurement system 

475 noise figure (high sensitivity to weak signals) in low-power portions of the radar emission 

476 spectrum.

 

5 Note that this test plan uses the terms “RF Front End” and “Preselector” almost synonymously. The Preselector is a 

function and component of the RF Front End and consists, in the current case, of a tunable YIG Bandpass filter.
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477

478 Figure 7. Block diagram of RF front end needed for wide dynamic range spectrum measurements.

479 The key to operation of the measurement system is to step across the emission spectrum one 

480 frequency at a time. Stepping means tuning the measurement system to a single frequency and 

481 then waiting long enough at that frequency for the transmitter (in this case an LTE system) to 

482 provide a statistically representative number of samples from which a root mean square (RMS) 

483 average power on that frequency may be computed. For LTE transmitters this interval has been 

484 found empirically to be 0.5 seconds or longer. During Phase II, the exact dwell time will be 

485 determined during the measurement and may be affected by the time needed for a peak 

486 measurement. When a measurement has been completed at a tuned frequency, the measurement 

487 system is tuned (stepped) to the next frequency to be measured. The frequency interval between 

488 tuning steps is usually equal to the resolution bandwidth of the measurement system. An 

489 additional measurement will be done with the frequency interval equal to the equivalent noise 

490 bandwidth of the smallest resolution bandwidth filter.

491 The stepped-frequency measurement process is described in detail in [4] for radars. For LTE 

492 measurements, this process is adapted as follows. Instead of running the spectrum analyzer in 

493 peak detection mode, the measurement system is operated in a sample-detection mode. In 

494 sampling mode, power levels are sampled randomly, and recorded, for the entire step interval. At 

495 the end of step interval, the peak and RMS power levels of those samples are computed, and 

496 those peak and RMS power levels are plotted as data points in the resulting measured spectra. 

497 This peak and RMS measurement process is repeated at each frequency step in the spectrum. 
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498 This stepped measurement process is repeated at each frequency step in the spectrum. For these 

499 LTE measurements, the measured spectra will be collected with both peak and RMS detection. 

500 The RMS spectrum points will be measured as the average of 1001 sample-detected points 

501 collected over an interval at each measured frequency step. The peak-detected point will be taken 

502 as the maximum measured power level (peak detected) during the interval.

503 Because stepped-frequency emission spectra are measured a single frequency at a time, the 

504 amount of attenuation invoked at the RF front end can be gradually adjusted as the measurement 

505 frequency steps progress across the spectrum. Zero attenuation is used in the lowest-power parts 

506 of the spectrum, maximum attenuation is used at the transmitter’s center frequency and 

507 intermediate amounts of attenuation are used at points in between. If a measurement system has 

508 60 dB of instantaneous dynamic range and a 70 dB step attenuator is built into the RF front end, 

509 the total measurement dynamic range can be as much as (60 dB + 70 dB) = 130 dB.

510 3.2. Circulators

511 Circulators are multi-port RF devices that permit power to flow in certain directions with low 

512 loss but which prevent the back-flow of power toward the point of origin along those same paths. 

513 Circulators are commonly used in radar RF front ends to 1) permit power to flow from the high514 power transmitter to the antenna while preventing that same power from flowing to the radar 

515 receiver at deleterious levels, and to 2) allow echo power from distant radar targets to flow 

516 backward from the antenna to the receiver with minimal loss.

517 In the UE emission spectrum measurement system a pair of three-port circulators will allow the 

518 base station emulator (R&S CMW-500, working as if it were an eNB) to communicate 

519 bi-directionally with the UE under test, while maintaining a degree of isolation (about 20 dB) 

520 between the CMW-500 and the spectrum measurement system. 

521 3.3. Spectrum Analyzer

522 The spectrum analyzer used in these measurements will likely be an Agilent (now Keysight 

523 Technologies) E4440A. However, any similar spectrum analyzer can be used. The E4440A is a 

524 high performance digital machine. A block diagram of the E4440A is shown in Figure 8.
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525

526 Figure 8. Block diagram of the E4440A digital spectrum analyzer with a stand-alone RF front end, as used for the 

527 UE and eNB spectrum measurements.

528 3.4. eNodeB (Base Station) Emulator

529 UEs will not operate unless they are in communication with eNodeB controllers. It is impractical 

530 to set up actual eNodeB stations for this purpose. So, eNodeB emulators are used instead. One 

531 solution is a base station emulator from Rohde and Schwarz, the CMW-500. The CMW-500 is 

532 used for communications design verification, feature testing and certification of user equipment 

533 (e.g., smartphones and dongles). The CMW-500 is capable of emulating all protocol layers: RF, 

534 physical, MAC, RRC, PDCP and IP. In Phase I and II testing, the CMW-500, is used to setup the 

535 smartphone to transmit in the carrier frequency and bandwidth of interest in order to measure 

536 OOBE. The CMW-500 is used to set the UE transmit power level and uses grants to control the 

537 resource blocks that the smartphone will transmit within the bandwidth of interest.
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538 4. UE Measurement Setup

539 Figure 9 shows a block diagram of the UE measurement system. The specialized custom RF 

540 front end has been built by NTIA, but could be replicated with similar components. The UE 

541 devices being measured will use OFDM modulation and will be frequency domain duplexed 

542 (FDD) with their controller. The controller will be a Rohde & Schwartz CMW-500 running as an 

evolved Node B (eNodeB).6543 The CMW-500 parameters during the emission measurements are 

544 shown in Table 1.

545

546 Figure 9. Block diagram of the UE emission spectrum measurement system.

547 To isolate the UE signal from the CMW-500 eNodeB signal for the spectrum measurement, the 

548 measurement system will use a pair of directional RF circulators that will be inserted between 

549 the UE and the eNodeB as shown in Figure 9. The circulators will provide about 20 dB of 

550 decoupling. The CMW-500 will also be operated at the lowest possible power level that still 

551 allows control of the each UE being measured. These expedients (RF circulators and minimal 

 

6 A Rohde and Schwartz CMW-500 operating in its eNodeB mode.
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552 CMW-500 power) will keep the CMW-500 emissions from contaminating the UE emission 

553 spectrum measurement results.

554 The UE and eNodeB signals will thus be forced to run in a loop between the two LTE units, with 

555 the UE signal on one side of the loop and the eNodeB signal on the loop’s other side. The 

556 measurement system takes the UE signal from an RF splitter on the UE side of the loop. The 

557 splitter has 4 dB of insertion loss; a 4 dB attenuator will be inserted between the circulators to 

558 ensure balanced RF path loss on both sides of the circulator loop. For the measurement system 

559 shown above, the system noise figure from the input to the RF front end would be approximately 

560 8 dB. The gain of the measurement system would be approximately 24 dB.

561 Table 1. Operating parameters of the R&S CMW-500 during UE spectrum measurements.

UE Parameter Parameter Value

Duplexing Frequency Division (FDD)

RF Modulation Quadrature Phase Shift Keying (QPSK)

Operating Radio Band AWS 3 (1775 MHz)

Commanded Full Cell Bandwidth 10.0 MHz (with 9 MHz actually occupied when 50 RBs 

were running)

Measured Total Output Power at Antenna Port +20.5 dBm (measured with an external power meter 

across full LTE bandwidth of 9 MHz)

Resource Block (RB) Energy Per Resource Element 

(EPRE) -100.0 dBm/15 kHz (indicated by eNodeB)

Full Cell Power -72.2 dBm (indicated by eNodeB)

Physical Uplink Shared Channel (PUSCH) Open Loop +23.0 dBm (indicated by eNodeB)

PUSCH Closed Loop +23.0 dBm (indicated by eNodeB)

Switching Packet

State Radio Resource Control (RRC)

Transfer Block Size Index (TBSI) (Downlink) 9

TBSI (Uplink) 6

Start Resource Block 0

Downlink Throughput (50 RBs) 4.795 Mbit/sec

Uplink Throughput (50 RBs) 2.064 Mbit/sec

Protocol Internet Protocol Version 4

Antenna Gain See main body text

562

563 As shown in Figure 9, the preferred method of connecting the UEs to the measurement system 

564 will be via hardline connections on the phone bodies. This can be a mechanically difficult 

565 process, but is possible for some UEs. For some UEs, however, no hardline connection will be 

566 possible. In this case, the UEs will be measured with a small horn antenna in a mini-anechoic 

567 chamber.

568 Whatever the method used for non-hardline connections, the measurement engineers will move 

569 the couplers around enough to identify the physical placement of the coupling antenna, relative 

570 to the UE, where maximum power is coupled into the measurement system. This is important 
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571 because the more power that gets into the measurement system, the more dynamic range will be 

572 obtained in the spectrum measurement. In all cases, the relative placement of the UE and the 

573 coupler will be recorded (including photographically) to document the placement of the units 

574 during the measurements.

575 5. UE Measurement Procedure

576 All measurements will be performed on UEs with the UE power having been maximized by 

577 running the CMW-500 eNB communication at the lowest possible power level. (UE power will 

578 be maximized by turning down CMW-500 power until the UE loses communication, and then 

579 bringing CMW-500 power back up by 3 dB.) Table 2 lists the measurements to be performed on 

580 each UE.

581 The relative offsets in measured power between a transmitter’s fundamental frequency and its 

582 OOBE will vary as a function of the resolution bandwidth and measurement detector mode. The 

583 amount of this variation is ultimately determined by the modulation of the transmitter’s 

584 emissions. For noise-like transmitter modulations that are root mean square (RMS) detected this 

585 variation will go as 10log(RBW), meaning that the power convolved in the RBW is directly 

586 proportional to the width of the RBW. For pulsed transmitter emissions this variation goes to its 

587 other extremum, 20log(RBW), if the emission is peak-detected. For various other modulations 

588 and measurement detectors the coefficient of the variation goes as some value between these 

589 extremes, i.e., the variation is between 10 and 20. In order to characterize this variation in OOBE 

590 relative to power at their fundamental frequencies for the transmitters in this study, the 

591 transmitters’ emissions need to be measured across a range of RBWs.

592 This variation in RBWs during the measurements allows the coefficient of the OOBE and 

593 spurious-to-fundamental power variation (always somewhere between 10 and 20) to be 

594 determined with certainty. With this variation known, the measurement results can be 

595 extrapolated to victim receivers with any given bandwidth, even if victim receiver bandwidths do 

596 not necessarily correspond to any actual measurement bandwidth used in this study.

597 As noted above, the dynamic range of each UE emission spectrum measurement will be 100 dB 

598 or more. Each measurement’s frequency range will be determined by this dynamic range. Based 

on Phase I measurement results, each UE spectrum measurement will be about 200 MHz wide.7599

600 Table 2. Measurement set for each UE.

Bandwidth Detector Resource Blocks

100 kHz RMS average Full Set (50)

300 kHz RMS average Full Set (50)

1 MHz RMS average Full Set (50)

3 MHz RMS average Full Set (50)

100 kHz Positive Peak Full Set (50)

 

7 The 100 db dynamic range of the spectrum measurements produces emission spectra that are about 200 MHz wide. 
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Bandwidth Detector Resource Blocks

300 kHz Positive Peak Full Set (50)

1 MHz Positive Peak Full Set (50)

3 MHz Positive Peak Full Set (50)

1 MHz RMS Half Set (25)

1 MHz RMS Quarter Set (12)

1 MHz RMS 1/10 Set (5)

1 MHz Positive Peak Half Set (25)

1 MHz Positive Peak Quarter Set (12)

1 MHz Positive Peak 1/10 Set (5)

601

602 The data set for each UE is described in Table 2. All data will be provided in a digital format. 

603 Emission spectra will be normalized to 0 dB at f0 in a 1 MHz resolution bandwidth.

604 The stepped-frequency measurement technique for collecting emission spectra provides a time605 domain collection at each measurement step. Each measurement frequency step for all collected 

606 emission spectra will consist of 1001 data points in the time domain. All of these points will be 

607 recorded. For each spectrum that is measured, time domain data consisting of 1001 points at each 

608 measured frequency step will be recorded and provided to the sponsor. These data will, like the 

609 spectrum data, be provided in a digital format for additional processing by the recipient.

610 For UEs where the coupled radiated method is used, the coupler should be physically scanned 

611 around the UE to determine the location where the energy coupled into the measurement system 

612 is the highest. 

613 6. eNodeB Measurement Setup

614 Figure 10 shows the setup for the eNB measurements. The measurement system will be 

615 essentially the same as, though somewhat simpler than, the UE setup. The system is simplified 

616 because the eNB can be operated stand-alone (unlike the UEs), without an associated radio to 

617 force it to operate.
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618

619 Figure 10. Block diagram of the eNB spectrum measurement system.

620 7. eNodeB Measurement Procedure

621 Phase I eNB emission spectrum measurements have shown that the measured power of these 

622 spectra can change by 80 dB or more within just a few megahertz of tuned spectrum. (This drop623 off is likely achieved by a combination of excellent modulation control and high-quality eNB 

624 transmitter output filtering.) This steep change, while good for spectrum engineering, does cause 

625 a problem for emission spectrum measurements.

626 The problem is that the center-frequency (f0) power from the transmitter can still be received in 

627 the measurement system, through the front-end yttrium-iron-garnet (YIG) filter, even when the 

628 measurement system is not tuned to f0; the YIG has a finite, non-zero bandwidth. For the NTIA 

629 measurement system, the YIG bandwidth is on the order of 25 MHz (although it varies with 

630 tuned frequency). This non-zero characteristic means that, if the transmitter’s power change with 

631 frequency is steep enough, it will still put enough power into the front end through the YIG to 

632 either overload the front end LNA or else overload the downstream spectrum analyzer IF stage 

633 when measurements are being performed close to, but not actually on, f0.

634 This problem could be solved by adding attenuation in the RF front end. But adding attenuation 

635 will put the transmitter’s OOB power on the tuned frequency of the measurement system below 

636 the measurement system’s noise floor. So, either the measurement system attenuation is kept low 

637 enough to allow the transmitter’s power on the measurement frequency to be seen, but 

638 concomitantly causing the transmitter’s f0 power to overload the measurement system, or else the 
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639 attenuation is increased enough to eliminate the overload condition while causing the transmitter 

640 power on the measurement system’s tuned frequency to be lost below the measurement system’s 

641 noise floor. Under this condition the available dynamic range for the measurement system goes 

642 from a nominal 100+ dB to zero dB. This is the spectrum measurement coffin corner problem.

643 The coffin corner occurs because the spectrum being measured changes steeply, relative to the 

644 width of the RF front-end YIG filter. Ideally the YIG could be made narrower, but that is not 

645 physically possible. The YIG can, however, be effectively made narrower on an ad-hoc basis 

646 relative to its frequency separation from f0. The way to do this is to not center-tune the YIG to 

647 the tuned frequency of the measurement system. Instead the YIG is off-tuned as much as 

648 possible from the measurement system’s tuned frequency. This off-tuning approach is shown 

649 graphically in Figure 11. 

650

651 Figure 11. YIG off-tuning technique that will be used for wide dynamic range eNB emission spectrum 

652 measurements. The YIG center is offset (∆f) from the measurement system’s tuned frequency up to the limit of the 

653 YIG’s 3-dB roll-off points, half of the YIG’s flat passband width.

654 The more the YIG can be off-tuned, the better for solving the coffin corner problem. In practice, 

655 the off-tuning is limited by the eventual roll-off of the YIG’s passband shape. The off-tuning is 

656 performed up to the 3 dB points in the filter’s rejection curve. As shown in Figure 11, the YIG 

657 off-tuning is downward when the transmitter’s spectrum is being measured below f0, and is 

658 upward for the transmitter’s spectrum above f0.

659 Sometimes the spectrum is so steeply changing that even off-tuning of the YIG does not 

660 completely solve the problem. But off-tuning of the YIG will always greatly reduce the number 

661 of frequency points where the coffin corner occurs, usually reducing the number of such points 

662 to either zero or else just a few on either side of f0. YIG off-tuning will be performed for the eNB 
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663 measurements, and will be done for UE measurements if the coffin corner problem should occur 

664 for any of them.

665 The eNB emission spectra will be measured with the transmitter running at full power and a 

666 power attenuator on its output to prevent burn-out of the measurement system. eNB emission 

667 data that will be collected are shown in Table 3.

668 The dynamic range of each UE emission spectrum measurement will be about 120 dB. This 

669 dynamic range will determine the measurement’s frequency range. Based on Phase I

670 measurement results, the eNB spectrum measurement will be about 300 MHz wide. The results 

671 of these Phase I tests can be found in Appendix Sections A.2.3 and A.3.3.

672 Table 3. Measurement set for the eNB.

Bandwidth Detector Resource Blocks Comments

100 kHz RMS average Full set (50) eNB tuned to center of band

300 kHz RMS average Full set (50) eNB tuned to center of band

1 MHz RMS average Full set (50) eNB tuned to center of band

3 MHz RMS average Full set (50) eNB tuned to center of band

100 kHz Positive peak Full set (50) eNB tuned to center of band

300 kHz Positive peak Full set (50) eNB tuned to center of band

1 MHz Positive peak Full set (50) eNB tuned to center of band

3 MHz Positive peak Full set (50) eNB tuned to center of band

1 MHz RMS Full set (50) eNB tuned to bottom of band

1 MHz RMS Full set (50) eNB tuned to top of band

1 MHz RMS Half set (25) eNB tuned to center of band

1 MHz RMS Quarter set (12) eNB tuned to center of band

1 MHz RMS 1/10 set (5) eNB tuned to center of band

1 MHz Positive peak Half set (25) eNB tuned to center of band

1 MHz Positive peak Quarter set (12) eNB tuned to center of band

1 MHz Positive peak 1/10 set (5) eNB tuned to center of band

673

674 8. Calibration Procedure

675 The measurement system will be calibrated with noise diodes. The basic approach is classic 

676 Y-factor, in which the noise diode is turned on at the front end of the measurement system at a 

known excess noise ratio8677 (ENR), say +25 dB, and the power from the diode is measured for a 

678 set of frequencies across the expected frequency range of the ensuing measurements. Then the 

679 diode is turned off and the output of the measurement system is measured is measured a second 

680 time for each of those calibration frequencies. The power difference between diode = ON and 

681 diode = OFF is then compared for each of those frequencies. Given that the noise diode’s ENR is 

 

8 ENR is relative to kTB, where k is Boltzmann’s constant (1.38^-23 J/K/Hz), T is the ambient 

temperature and B is the bandwidth in which the noise is observed or measured.
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682 already accurately known from separate, NIST-traceable calibrations of the component, the noise 

683 figure and gain of the measurement system at each calibration frequency is now known. Those 

684 calibration factors are stored in a frequency-dependent look-up table. They are retrieved and 

685 applied (that is, the measurement system’s gain corrections are applied) to the measured 

686 spectrum data on a point-by-point basis, the calibration factors for all measurement frequencies 

687 being interpolated from the look-up table calibration frequencies. Measured RF emission spectra 

688 are thus calibrated to power occurring at the noise diode calibration point.

689 As shown in Figure 7, the NTIA RF front end contains a built-in noise diode, but an external 

690 diode can be used if a different front-end system is used. This built-in diode will be used for the 

691 eNB measurement calibrations. For the UE spectrum measurements, however, a stand-alone 

692 noise diode will be used at the front of the first RF circulator, as shown in Figure 9.

693 9. Statistical Analysis

694 9.1. Relevant Experimental Variables

695  Response Variables: Samples of power spectral density for OOBEs from AWS-3 LTE 

696 signals. Peak and RMS power will be measured at each frequency as described in Section 5. 

697 In addition, all power samples over the specified dwell time will be recorded at each 

698 frequency.

699  Controlled Variables: measurement bandwidth, acquisition center frequency, attenuator 

700 setting, YIG tuning signal, LNA gain, measurement dwell time, LTE transmit settings (RB 

701 allocation and transmit power), experimental location (e.g., shielded room)

702  Uncontrolled Variables: environmental temperature and humidity, spurious emissions from 

703 external sources, heating of UEs due to power dissipation

704 9.2. Potential Sources of Uncertainty

705  Front-end gain 

706  Determined from pre-test calibration with noise diode

707  Frequency dependent

708  Used to scale measured power

709  Front-end noise 

710  RF connector repeatability (estimated from repeat measurements)

711  RF radiated measurement repeatability (estimated from repeat measurements)

712  Attenuator 

713  Inaccurate steps

714  Frequency dependence

715  Bandpass filter (YIG filter)

716  Non-flat passband

717  Error in YIG control signal 

718  Low Noise Amplifier (LNA)

719  Gain should be such that it drives system noise figure
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720  Impedance mismatches

721  Accuracy of power measurement from spectrum analyzer

722  LTE signal traffic

723  Resource Block allocations

724  Transmit power settings

725  Number and geometry of UEs

726  Spurious environmental noise 

727  For radiated measurements:

728  Thermal noise from antenna 

729  Channel variations

730 9.3. Analysis Plan

731 The emitted power P(f), centered at frequency f, will be obtained by adding a gain factor G(f)

732 to the observed power R(f) from the spectrum analyzer, i.e., P(f) = G(f) + R(f), where P(f)

733 and R(f) are expressed in dBm and G(f) is expressed in dB. Alternatively, if P(f) and R(f) are 

734 expressed in Watts, we write P(f) = G(f)R(f), where G(f) is a dimensionless power ratio. To 

735 simplify our notation below, we suppress the frequency dependence.

736 Measurement uncertainty will be assessed by estimating a confidence interval for P at each 

737 frequency. Note that due to the frequency-stepped nature of the measurement method, it is safe 

738 to assume that measurements made at different frequencies will be statistically independent, and 

739 therefore, uncorrelated. We will assume that when P is expressed in Watts, it follows a normal 

740 distribution, and estimate a confidence interval from estimates of P and its variance, denoted 

741 Var(P). The validity of the normality assumption will be checked with quantile-quantile (Q-Q) 

742 plots. In the event that this assumption is not met, resampling (e.g., bootstrapping) will be 

743 applied to estimate a confidence interval. Since the measured power will be reported in dBm, the 

744 confidence interval in Watts will be transformed to dBm. Due to the nonlinearity of this 

745 monotonic transformation, the resulting confidence interval in dBm will be asymmetric with 

746 respect to the estimate of P.

747 We can estimate both P and Var(P) from repeated measurements of G and R. Specifically, 

suppose that we have ngand nr 748 independent samples of G and R, respectively. Then the means 

749 and variances of G and R can be estimated from the sample with the usual unbiased sample 

means and variances, denoted g̅, r̅, sr

2

, and sg

2 750 . Since the gain will be estimated in pre-testing 

751 from independent measurements, it follows that G and R will be statistically independent. Under 

752 this assumption, P̂ = g̅r̅ is an unbiased estimated of P (in Watts), and a formula from [1] yields 

753 an unbiased estimate of Var(P̂), given by

Var ̂(P̂) = g̅

2

sr

2

nr

+ r̅

2

sg

2

ng

−

sg

2

sr

2

ngnr

(1)

754 The frequency-dependent gain factor, G, will be determined via a calibration using the Y-factor 

755 technique, which utilizes a noise diode as a standard noise source. By making repeated 
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756 measurements of G at different attenuator settings, the gain variability in the entire front-end will 

757 be assessed. Remaining measurement uncertainty will be captured by making repeated 

758 measurements of R. It is desirable to acquire repeated measurements in pre-testing, so that the 

759 expected magnitude of uncertainties can be roughly estimated, and to aid planning of the final 

760 experiment.

761 In addition to the above uncertainty assessment, the measurement system will also be 

762 characterized with various secondary measurements in pre-testing, e.g., 

763  System noise figure as function of frequency

764  System frequency response

765  Attenuator frequency response at various settings

766  Assessment of impedance mismatches

767  Assessment of change in UE emissions due to heating

768 If possible, uncertainties for these characterizations will be obtained from repeated 

769 measurements.

770 9.4. Potential Confounding Factors and Their Mitigation

771 Uncontrolled experimental factors include environmental conditions, spurious emissions from 

772 external sources, and heating of UEs due to power dissipation. The severity of these factors will 

773 be evaluated by visually inspecting scatter plots of all recorded power samples versus time.

774 Environmental conditions and spurious emissions can be controlled to a large degree for 

775 conducted measurements by carrying them out in a shielded room. For radiated measurements, 

776 environmental conditions and spurious emissions can be mitigated by using a longer dwell time 

777 and by distributing measurements over a longer time period. Changes in uplink LTE traffic due 

778 to UE power dissipation can be mitigated by shortening the UE transmission interval.

779 10. References

780 [1] Goodman L, “On the exact variance of products,” J. Am Stat. Assoc., Vol. 55, No. 292, 

781 Dec. 1960, pp. 708-713.

782 [2] North American Ericsson Mobility Report, November 2015; retrieved from 

783 http://www.ericsson.com/res/docs/2015/mobility-report/emr-nov-2015-regional-report784 north-america.pdf#page=2&zoom=100,-74,446

785 [3] Counterpoint Research, study results obtained from: 

786 http://www.insidermonkey.com/blog/10-most-sold-cell-phones-in-america-in-2015-

787 370257/

788 [4] Sanders, F.H.; Hinkle R.L.; Ramsey B.J., “Measurement procedures for the radar spectrum 

789 engineering criteria (RSEC),” NTIA Technical Report TR-05-420, U.S. Department of 
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790 Commerce, National Telecommunications and Information Administration, March 2005; 

791 retrieved from http://www.its.bldrdoc.gov/publications/2450.aspx

792 [5] Sanders, G.A.; Carroll, J.E.; Sanders, F.H.; Sole, R.L.; Achatz, R.J., “Emission spectrum 

793 measurements of a 3.5 GHz LTE hotspot,” NTIA Technical Report TR-15-512, U.S. 

794 Department of Commerce, National Telecommunications and Information Administration, 

795 February 2015; retrieved from http://www.its.bldrdoc.gov/publications/2790.aspx

796 [6] FCC Report and Order: “Amendment of the Commission’s Rules with Regard to 

797 Commercial Operations in the 1695-1710 MHz, 1755-1780 MHz, and 2155-2180 MHz 

798 Bands”, paragraph 62. March 31, 2014; retrieved from https://transition.fcc.gov/

799 Daily_Releases/Daily_Business/2014/db0401/FCC-14-31A1.pdf

800 [7] 3GPP TR 36.101 “Evolved Universal Terrestrial Radio Access (E-UTRA); User

801 Equipment (UE) radio transmission and reception;” retrieved from 

802 https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificati

803 onId=2411

804 [8] 3GPP 34.121 “Terminal conformance specification, Radio transmission and reception 

805 (FDD);” retrieved from https://portal.3gpp.org/desktopmodules/Specifications/

806 SpecificationDetails.aspx?specificationId=2362

807 [9] 3GPP TR 36.141 “Evolved Universal Terrestrial Radio Access (E-UTRA); Base Station 

808 (BS) conformance testing;” retrieved from https://portal.3gpp.org/desktopmodules/

809 Specifications/SpecificationDetails.aspx?specificationId=2421
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Appendix A - Phase I Measurements

To support the testing recommended in the Phase II Test Plan (main body of this document), 

Phase I measurements were conducted to shed light on the configurations required for both 

DUTs and measurement hardware. The purpose of the Phase II Test Plan is to define 

measurement methods for OOBE in AWS-3 bands (1755–1780 MHZ uplink and 2155–2180 

downlink). Because AWS-3 (3GPP Band 66) is newly licensed, equipment was not available for 

testing. To determine the test methodologies (subject of Phase I), 3GPP Band 3 equipment was 

used. For Phase I, results are presented for a single UE and a single eNodeB.9 Both the UE and 

eNodeB operate in 3GPP Band 3 also called LTE Band 3 (1710–1785 MHz uplink and 1805–

1880 MHz downlink). Band 3 was chosen because the frequencies are close (the uplink overlaps) 

and the equipment is readily available. Band 3 is not used in North America but it is used in 

other parts of the world.

A.1. RF Preselector Characterization10

In Phase I, a characterization of the RF measurement system was performed. Specific to the RF 

preselector that was used, a vector network analyzer was used to characterize the attenuation and 

impedance of the system.

Specific to the front-end system used in Phase I (described in Section 3.1, and shown in Figure 

A-1), a series of measurements were done. The front end can be switched into several modes. In 

bypass, there is no filter and no LNA, so only the attenuator has an effect. The attenuation was 

measured in bypass mode, but at higher attenuations readings became noisy.

To account for that, measurements were attempted in some of the bandpass modes. These 

include 500 MHz to 1 GHz, 1 GHz to 2 GHz, and 2 GHz to 4 GHz. Each bandpass filter also had 

an LNA. These gave more useful numbers at high attenuation, but less so at low attenuation. 

Each of these measurements were used to characterize the attenuation of the system. These data 

were used in the statistical analysis.

A.2. UE Measurements

A.2.1. UE Measurement Setup 

Figure A-1 shows a block diagram for the conducted UE measurement system. The custom RF 

front end was built by NTIA’s Institute for Telecommunication Sciences. The UE devices being 

measured use OFDM modulation and are frequency domain duplexed (FDD) with their 

controller. The controller was a Rohde & Schwartz Wideband Radio Communication Tester 

 

9 The validity of the test process is not dependent on the identity of the specific manufacturer of Band 3 equipment 

used.

10 Note that this test plan uses the terms “RF Front End” and “Preselector” almost synonymously. The Preselector is 

a function and component of the RF Front End and consists, in the current case, of a tunable YIG Bandpass filter.

See Phase II Test Plan Section 3.1 for details.
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Model CMW-500 running as an evolved Node B (eNodeB). The CMW-500 parameters during 

the emission measurements are shown in Table A-1.

Figure A-1. Block diagram of the UE emission spectrum measurement system.

To isolate the UE signal from the CMW-500 eNodeB signal for the spectrum measurement, the 

measurement system used a pair of directional RF circulators,

11 as shown in Figure A-1. The 

circulators provide about 20 dB of decoupling. The CMW-500 was operated at the lowest 

possible power level that still allows control of the each UE being measured. These expedients 

(RF circulators and minimal CMW-500 power) kept the CMW-500 emissions from 

contaminating the UE emission spectrum measurement results.

The UE and eNodeB signals were thus forced to run in a loop12 between the two LTE units, with 

the UE signal on one side of the loop and the eNodeB signal on the loop’s other side. The 

measurement system takes the UE signal from an RF splitter on the UE side of the loop. The 

splitter has 4 dB of insertion loss; a 4 dB attenuator13 was inserted between the circulators to 

 

11 Meca Electronics, Model # CN-1.400. The manufacturer’s specification is “15 dB typical, 13 dB minimum.” We 

measured the isolation to be greater than 18 dB across the frequency range of interest.

12 The loop is formed by circulator 1, circulator 2, the left side of the RF splitter, and back to circulator 1.

13 The 4dB attenuator was inserted to improve the impedance match between the two circulators.
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ensure balanced RF path loss on both sides of the circulator loop. The measurement system noise 

figure from the input to the RF front end was approximately 8 dB. The gain of the measurement 

system was approximately 24 dB. The measurement system noise and gain are measured 

between the input of the ITS RF Front End (left side of the simplified view block: location “A” 

in Figure A-1) and the output of the Agilent spectrum analyzer (left side of the spectrum analyzer 

block: location “B” in Figure A-1).

Table A-1. Operating parameters of the R&S CMW-500 during UE spectrum measurements.

UE Parameter Parameter Value

Duplexing Frequency Division (FDD) 

RF Modulation Quadrature Phase Shift Keying (QPSK)

Operating Radio Band 3GPP Band 3 (1775 MHz)

UE Uplink Carrier Frequency 1775 MHz

Uplink Resource Block Allocation 50 RB

Commanded Full Cell Bandwidth 10.0 MHz (with 9 MHz actually occupied when 50 RBs 

were running)

Measured Total Output Power at Antenna Port +20.5 dBm (measured with an external power meter 

across full LTE bandwidth of 9 MHz)

Resource Block (RB) Energy Per Resource Element 

(EPRE) -100.0 dBm/15 kHz (indicated by eNodeB)

Full Cell Power -72.2 dBm (indicated by eNodeB)

Physical Uplink Shared Channel (PUSCH) Open Loop +23.0 dBm (indicated by eNodeB)

PUSCH Closed Loop +30.0 dBm (indicated by eNodeB)

Switching packet

State Radio Resource Control (RRC)

Transfer Block Size Index (TBSI) (Downlink) 9

TBSI (Uplink) 6

Start Resource Block 0

Downlink Throughput (50 RBs) 4.795 Mbit/sec

Uplink Throughput (50 RBs) 2.064 Mbit/sec

Protocol Internet Protocol Version 4

Antenna Gain See main body text

In Phase I, the UE used had user accessible RF ports (located underneath the removable back 

cover of the UE). Therefore, a hardline connection was used for most measurements. However, 

in preparation for Phase II UEs that may not have accessible RF ports, a comparison 

measurement was done to demonstrate and verify that a radiated/coupled measurement would 

provide similar results. The radiated/coupled measurement was performed with a UE placed 

immediately in front of the aperture of a dual-ridged horn antenna inside a small anechoic 

chamber. Although the absolute power measurement at f0 was different for the two 

measurements (as expected), the shape of the emission spectrum was the same for the two 

coupling methods (see Figure 5, main body of this document).
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When coupled measurements were done in Phase I, the coupler was physically moved around the 

UE to determine the location where the energy coupled into the measurement system was 

maximized. Maximizing the coupled energy insures that the measurement system has sufficient 

dynamic range to make the measurement.

Figure A-2 shows the CMW-500 (top) used in this measurement. The spectrum analyzer shown 

(bottom) was only used for troubleshooting/verification. 

Figure A-2. The CMW-500 base station emulator (top) and one of the spectrum analyzers used to troubleshoot and 

verify the measurement setup (bottom).

The front-end/preselector and spectrum analyzer used to acquire the data in Phase I are shown in 

Figure A-3. The spectrum analyzer can be seen on the lower right side of the equipment stack 

(underneath the laptop). The three boxes on the left constitute the front-end/preselector. 
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Figure A-3. The spectrum analyzer (bottom right), acquisition laptop (on top of the spectrum analyzer), and RF 

preselector (3 box stack) used for both the UE and eNodeB measurements. 

Figure A-4 shows the hardline connection to the Phase I test UE. Figure A-5 shows the UE 

placed underneath the horn antenna for coupled/radiated testing.

Figure A-4. The UE used in Phase I measurements, shown with the hardline attached to one of the RF ports.
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Figure A-5. The UE placed inside the small anechoic chamber during the coupled/radiated testing. The UE is placed 

on top of foam blocks, and appears as a silver line immediately underneath the horn antenna.

Prior to measuring the UE emissions as coupled into a horn antenna, an attempt was made to use 

a passive inductive coupler, as shown in Figure A-6. Two different couplers were attempted, but 

both suffered from the same issue: the placement of the coupler in relation to the phone was 

extremely sensitive. After trial-and-error testing, it was determined that for the coupler shown in 

Figure A-6, the location of maximum coupling was offset from the phone in both the vertical and 

translation axes. This sensitivity made the use of the couplers impractical. 
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Figure A-6. The Phase I test UE is shown with the passive coupler banded to it.

A.2.2. Phase I UE Measurement Procedure

As the goal of Phase I was to investigate configurations of equipment and DUTs, much of the 

process was done via trial-and-error. The results of these quick measurements led to the 

decisions reflected in the Phase II test plan (main body of this document). The following 

elements were explicitly investigated to determine whether or not they have an impact on the 

final emissions of a UE/eNodeB, or the measurement configuration:

 Positive Peak vs. RMS Average Detectors on the Spectrum Analyzer: Because LTE 

signals vary rapidly with time, we examined the impact of using a positive peak or RMS 

average detector. Ultimately this comes down to the preference of the end-user: both produce 

valid results. The peak detector would show the worst case scenario, but it would give no 

indication of how frequently it occurs. To be complete, we suggest obtaining measured data 

with both detector types because it will give a more complete picture of what is seen on 

average and “worst-case.” Both positive peak and RMS average detectors were examined in 

Phase I. 

 Resolution Bandwidth of the Spectrum Analyzer: Varying the resolution bandwidth 

(RBW) of the spectrum analyzer impacts the “granularity” of the measured spectrum. Wide 

measurement bandwidths may obscure features in the spectrum that may be of interest. 

Narrow resolution bandwidth will provide more data, but take significantly more time to 

acquire. An additional consideration in the decision to use a given RBW is the end use of the 

data. If possible, the RBW of the measurement should match the RBW of the receiver of 
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interest (in this case an AMT receiver). Our understanding is that most AMT receivers use a 

RBW of 1 MHz, thus our suggestion is that most measurements be done with a 1 MHz RBW. 

This will help provide the most accurate picture of what the AMT receiver will “see.” 

Additional measurements are suggested in other RBWs for the purpose of future data 

analyses. In Phase I, RBWs of 100 KHz, 300 KHz, 1 MHz, and 3 MHz were examined. 

 LTE Resource Block Allocations: The OOBE of an LTE device may vary based on the 

resource block allocation of a given frame. Because resource block allocations are made 

dynamically based on the number of users in a sector and their demand for data, we suggest 

measuring several resource block configurations. Previous work has shown that the 

susceptibility of some devices (other than AMT receivers) may be influenced by the spectral 

changes caused by resource block allocations. In Phase I, resource block allocations of 50 

(full set), 25, 12, 5, and 1 were discussed. Only the full set of 50 was measured. The rest 

(25, 12, 5, and 1) will be considered for Phase II. 

 Modulation of Data within the LTE Signal: The modulation of the data used within an 

LTE signal was examined. Two modulations were considered: QPSK and 16-QAM. The use 

of QPSK appeared to result in a slight increase in the OOBE at some frequencies. Increases 

did not exceed approximately 4 dB. Though 16-QAM may end up being more prevalent, we 

suggest conducting measurements using the QPSK modulation. Devices that are operating 

near the noise floor (e.g., edge of a cell) may use QPSK instead of 16-QAM. 

 Output Power of the CMW-500: Ideally, the OOBE of the CMW-500 would have a 

negligible impact on the measurement of the UE’s OOBE. However, if the two are close 

enough in frequency, it may be possible for the CMW’s imperfections to influence the UE’s 

results. To limit this influence, we suggest keeping the output power of the CMW-500 at a 

minimum level. There is more risk of influence in the Phase I measurements because the UL 

and DL frequency bands are in much closer proximity than in actual AWS-3 deployments.

For all measurements performed on UEs, the UE power was maximized by turning down CMW500 power until the UE lost communication, and then bringing CMW-500 power back up by 3 

dB.

For Phase I, the emissions spectra measured were normalized to 0 dB at f0 in 1 MHz resolution 

(IF) bandwidth.

Phase I data were collected by use of the stepped-frequency measurement technique. This 

technique provides a time-domain collection at each measurement step. Each measurement 

frequency step for all collected emission spectra consisted of 1001 data points in the time 

domain. All of these points were recorded. 

A.2.3. Phase I UE Measurement Results

Figures A-7 and A-8 show the measured spectrum of the Band 3 UE. The FCC emissions mask 

is overlaid on the plots to illustrate the difference between the regulatory limit and the actual 

emissions. 
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Figure A-7. Conducted UE emission spectrum measurement. UE was operated at maximum power with all resource 

blocks occupied.

From [A-1], we know that the emissions mask in AWS-3 is similar to limits seen in other bands. 

The required suppression, S, outside the band edges is S [dB] = {43 + 10log(Ptotal)}. Suppression 

is given in dB below the maximum power, Ptotal in watts, that the transmitter is allowed to put 

into its own antenna. Transmitter antenna gain is not a factor in the mask limit. The suppression 

requirement is in units of decibels. The net effect is that the allowed OOBE is independent of 

transmitted power and is simply an absolute power level of -43 dBW or -13 dBm. Note that in 

Figures A-7 and A-8the +23 dBm UE transmit power appears at 0 dB due to normalization and 

the -13 dBm OOBE limit correspondingly appears at -36 dB.

The maximum width of the 95 % confidence intervals shown on these data was found to be 

0.06 dB/MHz. However, this estimate includes the statistical factors analyzed (see Section 9), 

exclusive of the RF measurement repeatability. The confidence interval is so small that it would 

not show in Figure A-7.
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45

Figure A-8. Radiated UE emission spectrum measurement. UE was operated at maximum power with all resource 

blocks occupied. Dashed lines show this uncertainty.

A.2.4. Phase I UE Measurement Conclusions

The UE measurement data shown indicates that OOBE drop off significantly outside the band. 

Though these measurements were done on a Band 3 (uplink 1710-1785 MHz) UE, it is 

reasonable to expect that the shape of AWS-3 (uplink 1755-1780 MHz) UEs’ OOBE, once 

deployed, should resemble this, as a similar type of power amplification and filtering will likely 

be used (but with different cut-off frequencies). Given that the measured UE spectra are more 

than 100 dB below the carrier frequency after +/−70 MHz, the +/−100 MHz suggested for Phase 

II should be more than adequate to capture the OOBE from AWS-3 hardware. 

Again, the data shown here are only roughly indicative of what could be expected in AWS-3. 

The measurements shown above are only for a single UE from a single manufacturer in Band 3. 

However, given that 80% of the Band 3 UE UL band is contained within the AWS 3 UE UL

band, the results may be very similar. 

Once acquired, these data can be used as an input to a more complete coexistence analysis to 

examine the impacts of AWS-3 OOBE on AMT receivers. 

A.3. eNodeB Measurements

Chronologically, the eNodeB measurements were performed after the UE measurements 

described in Section A.2 Therefore, there were few elements to investigate because the 

measurement system was already functioning and configured for LTE measurements. The fact 
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46

that there is already a 3GPP defined eNodeB test mode for the measurement of emissions also 

limits the amount of additional work that needs to be done.

It is important to note that although we used 3GPP eNodeB test mode for these measurements, 

we did not use the 3GPP test method. Rather, we continued to use the high-dynamic range 

measurement method described in this document. 

The LTE specifications found in 3GPP TS 36.141 [A-2] define the eNodeB standalone full-band 

transmission test mode. In this test mode, the eNodeB downlink emissions can be tested without 

the effect of UE uplink transmission. In Section 6.1.1 of the 3GPP document, several E-UTRA 

Test Models have been defined for setting up physical channels on the eNodeB to perform 

transmission testing. The most suitable model for measuring emissions from the transmission of 

an eNodeB is E-UTRA Test Mode (E-TM1.1). The characteristics of this model and its 

recommended usage are specified in Section 6.1.1.1 of 3GPP TS 36.141 [A-2].

A.3.1. eNodeB Measurement Setup

The measurement setup used to measure the eNodeB emissions was very similar to the setup 

used to measure the UE emissions. The output of the eNodeB was set to its maximum allowable 

output power, fed into an attenuator (to prevent burning out the measurement system), and then 

into the front-end/preselector. This setup is shown in Figure 10.Figure A-3. 

Because the eNodeB’s test mode forces the eNodeB to transmit with simulated downlink traffic, 

there is no need for a CMW-500, UE, or emulator of any kind. 

The eNodeB used for Phase I measurements is a Nokia FXED, deployed in late 2014. It runs 

software version FL15A. The eNodeB hardware used in Phase I is shown in Figure A-9, and 

includes a power supply, CPU and remote radio head.
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Figure A-9. The eNodeB hardware used in Phase I. The bottom of the three units is the power supply, the middle the 

CPU, and the top the remote radio head.

Figure A-10. eNodeB connection setup to measure downlink OOB emission.
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A.3.2. eNodeB Measurement Procedure

The eNodeB measurement procedure was the same as the UE measurement procedure. The only 

difference was that the yttrium-iron-garnet (YIG) off-tuning technique was implemented. Error! 

Reference source not found. shows a graph of the YIG off-tuning technique used for the wide 

dynamic range measurements of the eNB. See Section 7 of the main body of this document 

(AWS-3 OOBE Measurements Test and Metrology Phase II Test Plan) for details.

Figure A-11. YIG off-tuning technique used for wide dynamic range eNB emission spectrum measurements. The 

YIG center is offset (∆f) from the measurement system’s tuned frequency up to the limit of the YIG’s 3-dB roll-off 

points, half of the YIG’s flat passband width.

A.3.3. Phase I eNodeB Measurement Results

Figure A-12 shows the emission spectrum measured from the eNodeB. As with the UE 

measurements, the FCC emissions mask is shown for illustration purposes. Note that the same 

compensation for the difference between total and measured emissions discussed in Section 

A.2.4 was applied here as well. Thus in Figure A-12 the +40 dBm eNodeB transmit power 

appears at 0 dB and the -13 dBm OOBE limit appears at -53 dB correspondingly. The maximum 

width of the 95 % confidence interval for the data shown is 0.10 dB/MHz. However, this 

confidence interval does not account for the RF connector repeatability.
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Figure A-12. eNodeB conducted emission spectrum measurement. Transmitter operated at maximum power.

A.3.4. Phase I eNodeB Measurement Conclusions

The eNodeB measurement data shown indicates that OOBE drop off significantly outside the 

band. Though these measurements were done on a Band 3 (downlink 1805-1880 MHz) eNodeB, 

it is reasonable to expect that the shape of AWS-3 (downlink 2155-2180 MHz) eNodeB OOBE, 

once deployed, should resemble this as a similar type of power amplification and filtering will 

likely be used (but with different cut-off frequencies). Given that the measured eNodeB spectra 

are more than 100 dB below the carrier frequency after +/−30 MHz, the +/−150 MHz suggested 

for Phase II should be more than adequate to capture the OOBE from AWS-3 hardware. 

Again, the data shown here are only roughly indicative of what could be expected in AWS-3. 

The measurements shown above are only for a single eNodeB from a single manufacturer in 

Band 3. 

Once acquired, these data can be used as an input to a more complete coexistence analysis to 

examine the impacts of AWS-3 OOBE on AMT receivers. 

A.4. References

[A-1] FCC Report and Order: “Amendment of the Commission’s Rules with Regard to 

Commercial Operations in the 1695-1710 MHz, 1755-1780 MHz, and 2155-2180 MHz 

Bands”, paragraph 62. March 31, 2014; retrieved from https://transition.fcc.gov/

Daily_Releases/Daily_Business/2014/db0401/FCC-14-31A1.pdf
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[A-2] 3GPP TR 36.141 “Evolved Universal Terrestrial Radio Access (E-UTRA); Base Station 

(BS) conformance testing;” ; retrieved from https://portal.3gpp.org/desktopmodules/

Specifications/SpecificationDetails.aspx?specificationId=2421
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4. TITLE AND SUBTITLE

AWS-3 Out of Band Emissions Measurements Test and Metrology Phase II Test Plan

5a. CONTRACT NUMBER

!AA 1603-670-01

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

Arthur Webster, Sheryl Genco, Jason Coder, Brent Bedford, Adam Wunderlich, Jean-Aicard 

Fabien, Frank Sanders, John Ladbury, Azizollah Kord

5d. PROJECT NUMBER

6793000-300

5e. TASK NUMBER

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7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

National Telecommunications and Information Administration, Institute for Telecommunication Sciences

325 Broadway, MS NTIA/ITS.D

Boulder, CO 80305

National Institute of Standards and Technology, Communications Technology Laboratory

325 Broadway

Boulder, CO 80305

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412th Test Engineering Group

Spectrum Relocation Program

307 E. Popson Avenue, Suite 204

Edwards AFB, CA 93524

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Approved for Public Release. Distribution Unlimited.

13. SUPPLEMENTARY NOTES

14. ABSTRACT

Wide dynamic range emission measurements of LTE mobile phones (user equipment, or UEs) and base station hardware (eNodeBs) that will share spectrum with telemetry 

links in the newly available AWS-3 band U.S (designated Band 66 by 3GPP) are needed. These measurement results will be fed into interference analyses for band sharing 

studies. The ultimate goal is to know how much frequency and distance separation will be needed between LTE hardware and telemetry receivers, so as to preclude 

harmful interference from UEs to telemetry links when the band is eventually shared by these systems. This document describes emission measurements that will be 

performed on a variety of LTE UEs and eNodeBs that will be deployed in the AWS-3 band. As a precursor to these measurements, a measurement method is outlined and 

demonstrated for Band 3 hardware (note that the uplink for Bands 3 and 66 overlap).

15. SUBJECT TERMS

Band sharing; band sharing analysis; interference analysis; eNodeB (eNB); emission spectrum; telemetry links; user equipment (UE)

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ABSTRACT

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Sheryl M. Genco, Ph.D a. REPORT

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