Test Report 2

FCC ID: 2ABCB-RPI4B

Test Report

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TEST REPORT Test Report No. : UL-RPT-RP12663640-1616B Customer : Raspberry Pi (trading) Ltd Model No. : Raspberry Pi 4 Model B FCC ID : 2ABCB-RPI4B Technology : WLAN Test Standard(s) : FCC Part 15.407(h)(2) 1. This test report shall not be reproduced except in full, without the written approval of UL VS LTD. 2. The results in this report apply only to the sample(s) tested. 3. The sample tested is in compliance with the above standard(s). 4. The test results in this report are traceable to the national or international standards. 5. Version 1.0 Date of Issue: 10 May 2019 Checked by: Ben Mercer Senior Test Engineer, Radio Laboratory Company Signatory: Sarah Williams Senior Test Engineer, Radio Laboratory UL VS LTD UL VS LTD Unit 1-3 Horizon, Wade Road, Kingsland Business Park, Basingstoke, Hampshire, RG24 8AH, UK Telephone: +44 (0)1256 312000 Facsimile: +44 (0)1256 312001

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 Customer Information Company Name: Raspberry Pi (Trading) Ltd Address: Maurice Wilkes Building Cowley Road Cambridge CB4 0DS United Kingdom Report Revision History Version Issue Date Revision Details Revised By Number 1.0 10/05/2019 Initial Version Ben Mercer Page 2 of 18 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 Table of Contents Customer Information..................................................................................................................2 Report Revision History ..............................................................................................................2 1. Attestation of Test Results ......................................................................................................4 1.1. Description of EUT 4 1.2. General Information 4 1.3. Summary of Test Results 4 1.4. Deviations from the Test Specification 4 2. Summary of Testing.................................................................................................................5 2.1. Facilities and Accreditation 5 2.2. Methods and Procedures 5 2.3. Calibration and Uncertainty 5 2.4. Test and Measurement Equipment 6 3. Equipment Under Test (EUT) ..................................................................................................7 3.1. Identification of Equipment Under Test (EUT) 7 3.2. Modifications Incorporated in the EUT 7 3.3. Additional Information Related to Testing 7 3.4. Description of Available Antennas 7 3.5. Description of Test Setup 8 4. Test Results ...........................................................................................................................11 4.1. Channel Closing Transmission Time and Channel Move Time 11 4.2. Non-occupancy Period 14 Appendix 1. Radar Type 0 Calibration ......................................................................................16 Appendix 2. System Noise Floor Reference Plots ...................................................................17 Appendix 3. Channel Loading ...................................................................................................18 UL VS LTD Page 3 of 18

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 1. Attestation of Test Results 1.1. Description of EUT The Equipment Under Test was a single board computer. It contains a Bluetooth, 2.4 GHz and 5 GHz WLAN module powered from an AC/DC power supply. The antenna is integral. 1.2. General Information Specification Reference: 47CFR15.407 Specification Title: Code of Federal Regulations Volume 47 (Telecommunications): Part 15 Subpart E (Unlicensed National Information Infrastructure Devices) - Section 15.407 Test Date: 11 April 2019 1.3. Summary of Test Results FCC Reference Measurement Note Result (47CFR) Channel Closing Transmission Time and Channel Move Part 15.407(h)(2)(iii) - Time Part 15.407(h)(2)(iv) Non-Occupancy Period 2 Key to Results = Complied = Did not comply Note(s): 1. The manufacturer confirms that the information regarding the parameters of the radar waveforms is not available to the end user. 2. This test is not required for a client without radar detection according to Tables 1 and 2 of KDB 905462 D02, however it was performed to show compliance with KDB 905462 D02 5.1.2 e) and KDB 905462 D03, section (b)(5) and (b)(6). 1.4. Deviations from the Test Specification For the measurements contained within this test report, there were no deviations from, additions to, or exclusions from the test specification identified above. Page 4 of 18 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 2. Summary of Testing 2.1. Facilities and Accreditation The test site and measurement facilities used to collect data are located at Unit 3 Horizon, Wade Road, Kingsland Business Park, Basingstoke, Hampshire, RG24 8AH, United Kingdom. UL VS LTD is accredited by UKAS. The tests reported herein have been performed in accordance with its terms of accreditation. 2.2. Methods and Procedures Reference: FCC KDB 905462 D02 UNII DFS Compliance Procedures New Rules v02 (April 08, 2016) Title: Compliance Measurement Procedures for Unlicensed-National Information Infrastructure Devices Operating in the 5250-5350 MHz and 5470-5725 MHz Bands Incorporating Dynamic Frequency Selection 2.3. Calibration and Uncertainty Measuring Instrument Calibration In accordance with UKAS requirements all the measurement equipment is on a calibration schedule. All equipment was within the calibration period on the date of testing. Measurement Uncertainty No measurement or test can ever be perfect and the imperfections give rise to error of measurement in the results. Consequently the result of a measurement is only an approximation to the value measured (the specific quantity subject to measurement) and is only complete when accompanied by a statement of the uncertainty of the approximation. The expression of uncertainty of a measurement result allows realistic comparison of results with reference values and limits given in specifications and standards. The uncertainty of the result may need to be taken into account when interpreting the measurement results. The reported expanded uncertainties below are based on a standard uncertainty multiplied by an appropriate coverage factor such that a confidence level of approximately 95% is maintained. For the purposes of this document “approximately” is interpreted as meaning “effectively” or “for most practical purposes”. Confidence Level Calculated Measurement Type (%) Uncertainty DFS Channel Shutdown Timing 95% ±0.45 ms DFS Non-Occupancy Timing 95% ±79.25 ms DFS Radar Amplitude 95% ±2.17 dB The methods used to calculate the above uncertainties are in line with those recommended within the various measurement specifications. Where measurement specifications do not include guidelines for the evaluation of measurement uncertainty the published guidance of the appropriate accreditation body is followed. UL VS LTD Page 5 of 18

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 2.4. Test and Measurement Equipment Test Equipment Used: Cal. Asset Date Calibration Instrument Manufacturer Type No. Serial No. Interval No. Due (Months) M2001 Thermohygrometer Testo 608-H1 45041824 06 Jan 2020 12 M1835 Signal Analyser Rohde & Schwarz FSV30 103050 01 Apr 2020 12 Vector Signal G0615 Rohde & Schwarz SMBV100A 260473 08 May 2020 36 Generator Calibrated before A248 Step Attenuator Narda 743-60 01411 - use 8494B & 30801/ Calibrated before A1536 Step Attenuator Hewlett Packard - 8496B 19649 use Calibrated before A465 Step Attenuator Hewlett Packard 8496B 3131P324 - use Calibrated before A1065 Step Attenuator Hewlett Packard 8496B 3308A38165 - use ACC-20130- Calibrated before A2183 Coaxial Circulator AtlanTecRF 120409232 - SF-SF-SF use ACC-20130- Calibrated before A2913 Coaxial Circulator AtlanTecRF 1350504366 - SF-SF-SF use Weinschel Calibrated before A2016 Power Divider 1515 MH084 - Engineering use Page 6 of 18 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 3. Equipment Under Test (EUT) 3.1. Identification of Equipment Under Test (EUT) Brand Name: Raspberry Pi Model Name or Number: Raspberry Pi 4 Model B Test Sample Serial Number: 000000003268236e Hardware Version: V1.0 Software Version: V1.0 FCC ID: 2ABCB-RPI4B 3.2. Modifications Incorporated in the EUT No modifications were applied to the EUT during testing. 3.3. Additional Information Related to Testing Technology Tested: WLAN (IEEE 802.11a,n,ac) / U-NII Type of Unit: Transceiver Modulation Types: BPSK, QPSK, 16QAM, 64QAM & 256QAM Transmit / Receive Frequency 5250 to 5350 MHz Range: 5470 to 5850 MHz Transmit / Receive Channels Tested Channel Centre Frequency Channel ID at 80 MHz Bandwidth setting: (MHz) 58 (Control Channel 52) 5290 3.4. Description of Available Antennas The radio utilizes an integrated antenna of 50 Ω impedance. The maximum gain is shown below: Frequency Band GAntenna (MHz) (dBi) 5250 to 5350 2.3 UL VS LTD Page 7 of 18

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 3.5. Description of Test Setup Support Equipment The following support equipment was used to exercise the EUT during testing: Description: Wireless Dual Band Router (DFS Master) Brand Name: Cisco Model Name or Number: AIR-CAP3702E-A-K9 V04 FCC ID: LDK102087 Serial Number: FJC1938F3G6 Description: Test Laptop Brand Name: Dell Model Name or Number: Latitude E5400 Serial Number: JX19G4J Operating Modes The EUT was tested in the following operating modes, unless otherwise stated: • Operating on the channel selected by the Master device in either band U-NII-2A or U-NII-2C. • The Master device controls the channel bandwidth of the EUT. Both the Master and Client device were set to 802.11ac / MCS0x1 with 80 MHz channel bandwidth to ensure a stable channel loading. • KDB 905462 D02 v02 UNII DFS Compliance Procedures states in Table 2 the EUT should be tested at maximum channel bandwidth (80 MHz for 802.11ac mode). • For the required channel loading of >17% in KDB 905642 D02 7.7 c), a UDP data transfer of 7.5 Mbit/s was performed between a test computer connected to the DFS Master device and the EUT. This gave a channel loading (duty cycle) of 43% at the modulation scheme and bandwidth above. See Appendix 3 Channel Loading for further details. Page 8 of 18 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 Configuration and Peripherals The EUT was tested in the following configuration(s): • The EUT is a DFS Client without Radar Detection capability. It was tested in combination with an FCC approved Cisco DFS enabled router (FCC ID: LDK102087) being used as the Master. A Radar Type 0 was injected to the Master to test the Clients Channel Move Time and Channel Closing Transmission Time after receiving the channel shutdown command from the Master. • All measurements were made using a conducted link. The EUT has one external antenna port fitted for test purposes. System losses for the interconnecting hardware were measured and taken into consideration. • The DFS detection threshold of -61.0 dBm (-62 + 1 dB + 0 dBi) was used at the Master device antenna port. Note this is not dependent on the EUT EIRP, Spectral Density or EUT Antenna Gain, only the antenna gain of the master device, as the EUT does not have radar detection. The Cisco DFS Master test router was configured with an internal setting for a 0 dBi antenna. KDB 905462 D02 Table 3: DFS Detection Thresholds for Master Devices and Client Devices With Radar Detection Maximum Transmit Power Value (see notes) EIRP ≥ 200 milliwatt -64 dBm EIRP < 200 milliwatt and -62 dBm power spectral density < 10 dBm/MHz EIRP < 200 milliwatt that do not meet the power -64 dBm spectral density requirement Note 1: This is the level at the input of the receiver assuming a 0 dBi receive antenna Note 2: Throughout these test procedures an additional 1dB has been added to the amplitude of the test transmission waveforms to account for variations in measurement equipment. This will ensure that the test signal is at or above the detection threshold level to trigger a DFS response. Note 3: EIRP is based on the highest antenna gain. For MIMO devices refer to KDB Publication 662911 D01. • The Master device used for test was set to 17 dBm / 50 mW with TPC enabled. • Plots and data were captured using a Rohde and Schwarz FSV 30 Spectrum Analyser. The number of data points was increased to maximum and the trace data exported so it could be analysed in far greater detail than available on the built-in display. • The Channel Move Time was the time taken from the end of the radar waveform to the time the Client ceased transmissions. The Channel Closing Transmission Time was calculated to the nearest sample from any additional pulses occurring >200 ms after the end of the radar. UL VS LTD Page 9 of 18

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 Test Setup Diagrams Setup diagram for test of DFS Client without Radar Detection: Setup 1 Radar Generator S 6 dB RF Splitter 1 2 Spectrum Analyser 20 dB 1 RF Circulator EUT Master 25 dB 2 3 1 3 5 dB (Client) RF Circulator 2 50 Ω Rationale The setup shown above ensures the waveforms indicated on the spectrum analyser are in order of magnitude. The circulators have typically 18 dB attenuation in the reverse direction. The left-hand circulator directs the radar towards the master, ensuring there is not an overly large radar pulse into the client (EUT) even though there is the more attenuation between the circulator and the master. The right-hand circulator is to give the same path loss between master and client in both directions of the 802.11 communications link. The Radar signal is most predominant on the spectrum analyser, coming straight through a 6 dB splitter. The client is 2nd largest, being attenuated by the 5 dB and 20 dB Attenuators, and the 6 dB splitter. The smallest signal is the master, being attenuated by 25 dB and 20 dB attenuators and approximately 6 dB from the left- hand circulator and 18 dB across the splitter. The RF path from the radar generator to the DFS Master crosses no isolated ports of any splitters or circulators and any change of impedance in load between calibration and test is isolated from any circulators by 50 Ω attenuators which further minimises mismatch. This setup therefore meets the requirements of KDB 905462 D02 clause 7.2 points (A) and (B) whilst providing greater radar generator amplitude headroom and lower radar signal at the client. Page 10 of 18 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 4. Test Results 4.1. Channel Closing Transmission Time and Channel Move Time Test Summary: Test Engineer: Matthew Botfield Test Date: 11 April 2019 Test Sample Serial Number: 000000003268236e FCC Reference: Part 15.407(h)(2)(iii) Test Method Used: KDB 905462 D02 Section 7.8.3 Environmental Conditions: Temperature (°C): 20 Relative Humidity (%): 48 Note(s): 1. The channel move time is the time taken from the end of the radar burst to the ceasing of transmissions of the EUT. 2. The Total Aggregate Channel Closing Transmission Time shown in the table below was measured from 200 ms after the end of the radar burst and compared to the 60 ms limit. 3. Although the EUT and DFS Master device 80 MHz operating channel was centred on 5290 MHz, the spectrum analyser was tuned to zero span at 5260 MHz. The radar was also fired at 5260 MHz. This was the control channel of the DFS Master device, and hence any additional control signals seen would occur in this 20 MHz part of the channel bandwidth, along with any of the wider-band data transfer. 4. The smaller transmissions seen in the plot below -10 dBm come from either the Master device and not from the EUT. These transmissions can be ignored for the below results. Results: Setup 1 - Channel Move Time Channel Move Time Limit Margin Result (MHz) (ms) (ms) (ms) 5290 83.3 10000 9916.7 Complied Results: Setup 1 - Channel Closing Transmission Time Total Aggregate Tx Time Occurring Channel Limit Margin After time Result (MHz) (ms) (ms) [t1+200 ms] (ms) 5290 0.0 60.0 60.0 Complied UL VS LTD Page 11 of 18

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 Channel Closing Transmission Time and Channel Move Time (continued) Results: Setup 1 / 80 MHz EUT to Master Plot showing the full 10 second shutdown limit Zoomed plot showing the first 200 ms after the end of the type 0 radar burst Page 12 of 18 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 Channel Closing Transmission Time and Channel Move Time (continued) Limits: Part 15.407(h)(2)(iii) After a radar's presence is detected, all transmissions shall cease on the operating channel within 10 seconds. Transmissions during this period shall consist of normal traffic for a maximum of 200 ms after detection of the radar signal. In addition, intermittent management and control signals can be sent during the remaining time to facilitate vacating the operating channel. KDB 905462 D02 Table 4: DFS Response Requirement Values Parameter Value Channel Move Time 10 seconds See Note 1. Channel Closing Transmission Time 200 milliseconds + an aggregate of 60 milliseconds over remaining 10 second period. See Notes 1 and 2. Note 1: Channel Move Time and the Channel Closing Transmission Time should be performed with Radar Type 0. The measurement timing begins at the end of the Radar Type 0 burst. Note 2: The Channel Closing Transmission Time is comprised of 200 milliseconds starting at the beginning of the Channel Move Time plus any additional intermittent control signals required to facilitate a Channel move (an aggregate of 60 milliseconds) during the remainder of the 10 second period. The aggregate duration of control signals will not count quiet periods in between transmissions. UL VS LTD Page 13 of 18

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 4.2. Non-occupancy Period Test Summary: Test Engineer: Matthew Botfield Test Date: 11 April 2019 Test Sample Serial Number: 000000003268236e FCC Reference: Part 15.407(h)(2)(iv) Test Method Used: KDB 905462 D02 Section 7.8.3 Environmental Conditions: Temperature (°C): 20 Relative Humidity (%): 48 Notes: 1. This test is not required for a client without radar detection according to Tables 1 and 2 of KDB 905462 D02, however it was performed to show compliance with KDB 905462 D02 5.1.2 e) and KDB 905462 D03, section (b)(5) and (b)(6). Therefore no specified bandwidth requirement is given and so was performed using an 80 MHz channel bandwidth; as used for Channel Closing Transmission Time and Channel Move Time. 2. Radar burst type 0 was detected and the channel was vacated for >1800 seconds. Since the client has no radar detection and is therefore not performing an ‘intelligent’ blacklisting of the channel, the device was shown not to transmit for greater than 30 minutes after its own shutdown time, not the shutdown of the DFS Master. 3. Although the EUT and Master device 80 MHz operating channel was centred on 5290 MHz, the spectrum analyser was tuned to zero span at the centre of the Master device control channel; 5260 MHz. The radar was also tuned to this frequency. This allowed any control signals to be monitored in addition to the 80 MHz data transfer. 4. The noise floor remained below the -21.2 dBm/MHz (74 dBµV/m at 3m) unintentional radiator limit for the 30 minute (1800 second) non-occupancy period. Therefore the EUT is deemed to comply. Page 14 of 18 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 Non-occupancy Period (continued) Results: Setup 1 Channel Non-Occ Limit Margin Result (MHz) (min) (min) (min) 5260 >34.5 30.0 >4.5 Complied Limits: Part 15.407(h)(2)(iv) A channel that has been flagged as containing a radar system, either by a channel availability check or in- service monitoring, is subject to a non-occupancy period of at least 30 minutes. The non-occupancy period starts at the time when the radar system is detected. KDB 905462 D02 Table 4: DFS Response Requirement Values Parameter Value Non-occupancy period Minimum 30 minutes UL VS LTD Page 15 of 18

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 Appendix 1. Radar Type 0 Calibration Radar calibration procedure. The system was configured as shown in section 3.5, but with the spectrum analyser port terminated into a 50Ω load, and a spectrum analyser connected to the master port. The radar was then replayed by the Rohde & Schwarz vector signal generator DFS test system, the waveform captured, and the amplitude adjusted until correct. 12663640 Date:11.APR.2019 16:42:38 Radar Type 0 – full 18 pulse waveform Page 16 of 18 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 Appendix 2. System Noise Floor Reference Plots As required by Section 8.3 d) 3) of KDB 905462 D02, the following plot shows the reference noise floor of the system used during measurement. It also shows compliance with Section 8.3.7 of KDB 905462 D02 when the path loss of the coupling network shown in Section 3.5 Configuration and Peripherals is added to the noise floor. 12663640 Date:11.APR.2019 17:10:04 Noise Floor of Spectrum Analyser UL VS LTD Page 17 of 18

TEST REPORT SERIAL NO: UL-RPT-RP12663640-1616B VERSION 1.0 ISSUE DATE: 10 MAY 2019 Appendix 3. Channel Loading As required by Section 8.3. c) 6) of KDB 905462 D02, the following plot and calculations shows the duty cycle of the channel used during testing. When using an 80 MHz channel bandwidth, streaming representative file types as defined in Section 7.7 a) of KDB 605642 D02 was not found to produce a duty cycle of >17% as required by 7.7 c). It was also found to produce irregular loading due to large video buffers. Therefore an alternative UDP pseudo-random data transfer as defined in 7.7 b) was streamed to simulate data transfer. The duty cycle was calculated over 100 milliseconds. This was captured on a spectrum analyser in the time domain using a 0 Hz span and 32000 sweep points to ensure it included any longer term variations, whilst maintaining accurate to a 375 µs sample size. 12663640 Date:11.APR.2019 17:01:13 The number of samples greater than -30 dBm was compared to the total number of samples to calculate the duty cycle. The EUT and test router were found to be transmitting above this threshold for 43 % of the total, and hence meeting the requirement of greater than 17 % channel loading. --- END OF REPORT --- Page 18 of 18 UL VS LTD


Document Created: 2019-06-24 10:07:54
Document Modified: 2019-06-24 10:07:54
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