Tset Report 5GHz DFS

FCC ID: 2ABCB-RPI3BP

Test Report

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TEST REPORT SERIAL NO: UL-RPT-RP11913492-2416C

VERSION 1.0 ISSUE DATE: 28 FEBRUARY 2018

1. Customer Information
Company Name: Raspberry Pi (Trading) Ltd
Address: 30 Station Road,
Cambridge.
CB1 2JH
United Kingdom

Page 4 of 24 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP11913492-2416C

VERSION 1.0 ISSUE DATE: 28 FEBRUARY 2018

4.2. 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 form 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 Radar test platform used was a SMBV100A Vector Signal Generator.
• The DFS detection threshold of -56.0 dBm (-62 + 1 dB + 5 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 5 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 power spectral density < 10 dBm/MHz -62 dBm
EIRP < 200 milliwatt that do not meet the power spectral density -64 dBm
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 1 dB 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 Signal Analyser. The number of
data points was increased to maximum and the trace data exported so it could be analysed in
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 24

TEST REPORT SERIAL NO: UL-RPT-RP11913492-2416C

VERSION 1.0 ISSUE DATE: 28 FEBRUARY 2018

Setup diagram for test of DFS Client without Radar Detection: Setup 1

Radar Test
Signal
Generator

3dB RF
Splitter

Signal
Analyser

1
LAN RF
Circulator
30 20
2 3 1 3 dB
Master Device dB RF Client
Circulator Device
(EUT)
2

50Ω
PSU PSU

Rationale
The setup shown above ensures the waveforms indicated on the signal 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 same attenuation between the client and the radar generator. The radar signal should be
approximately 26 dB smaller at the client antenna port than at 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 signal analyser, coming straight through a 3 dB splitter. The
client is 2nd largest, being attenuated by the 20 dB, and the (typically 18 dB) isolation from the directional
splitter. The smallest signal is the master, being attenuated by 30 dB from the attenuator and approximately
18 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 24 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP11913492-2416C

VERSION 1.0 ISSUE DATE: 28 FEBRUARY 2018

Applicability of DFS requirements prior to use of a channel
Requirement Operational Mode

Master Client Client
Without Radar With Radar
Detection Detection
Non-Occupancy Period Yes Not required Yes
DFS Detection Threshold Yes Not required Yes
Channel Availability Check Time Yes Not required Not required
Uniform Spreading Yes Not required Yes

Applicability of DFS requirements during normal operation
Requirement Operational Mode

Master Device or Client with Client Without Radar
Radar Detection Detection
DFS Detection Threshold Yes Not required
Channel Closing Transmission Time Yes Yes
Channel Move Time Yes Yes
U-NII Detection Bandwidth Yes Not required

Additional requirements for devices Master Device or Client with Client Without Radar
with multiple bandwidth modes Radar Detection Detection
U-NII Detection Bandwidth and
All BW modes must be tested Not required
Statistical Peformance Check
Channel Move Time and Channel Test using widest BW mode Test using the widest BW
Closing Transmission Time available mode available for the link
All other tests Any single BW mode Not required
Note: Frequencies selected for statistical performance check (Section 7.8.4) should include several frequencies within
the radar detection bandwidth and frequencies near the edge of the radar detection bandwidth. For 802.11 devices it is
suggested to select frequencies in each of the bonded 20 MHz channels and the channel center frequency.

Interference Threshold values, Master or Client incorporating In-Service Monitoring
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 spectral
-64 dBm
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.

UL VS LTD Page 11 of 24

TEST REPORT SERIAL NO: UL-RPT-RP11913492-2416C

VERSION 1.0 ISSUE DATE: 28 FEBRUARY 2018

DFS Response requirement values
Parameter Value
Non-occupancy period Minimum 30 minutes
Channel Availability Check Time 60 seconds
Channel Move Time 10 seconds See Note 1.
200 milliseconds + an aggregate of 60
Channel Closing Transmission Time milliseconds over remaining 10 second period.
See Notes 1 and 2.
Minimum 100% of the U-NII 99% transmission
U-NII Detection Bandwidth
power bandwidth. See Note 3.
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.
Note 3: During the U-NII Detection Bandwidth detection test, radar type 0 should be used. For each frequency step the
minimum percentage of detection is 90 percent. Measurements are performed with no data traffic.

Short Pulse Radar Test Waveforms
Radar Type Pulse Width PRI Pulses Minimum Minimum
(Microseconds) (Microseconds) Percentage of Trials
Successful
Detection

0 1 1428 18 See Note 1 See Note 1
Note 1: should be used for the detection bandwidth test, channel move time and channel closing time tests.

Page 12 of 24 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP11913492-2416C

VERSION 1.0 ISSUE DATE: 28 FEBRUARY 2018

5. Measurements, Examinations and Derived Results
5.1. General Comments
Measurement uncertainties are evaluated in accordance with current best practice. Our reported expanded
uncertainties are based on standard uncertainties, which are multiplied by an appropriate coverage factor to
provide a statistical confidence level of approximately 95%. Please refer to Section 6 Measurement
Uncertainty for details.
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.

UL VS LTD Page 13 of 24

TEST REPORT SERIAL NO: UL-RPT-RP11913492-2416C

VERSION 1.0 ISSUE DATE: 28 FEBRUARY 2018

5.2. Test Results
5.2.1. Channel Closing Transmission Time and Channel Move Time
Test Summary:

Test Engineer: Max Passell Test Dates: 12 February 2018 to
14 February 2018
Test Sample Serial Number: Not marked or stated (Conducted Sample)

FCC Reference: Part 15.407(h)(2)(iii)
Test Method Used: KDB 905462 D02 Section 7.8.3

Environmental Conditions:

Temperature (°C): 22 to 23
Relative Humidity (%): 35 to 37

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. Radar burst type 0 was detected and channel move occurred.

Results:

Channel Frequency Channel Move Limit Margin
Result
(MHz) Time (ms) (ms) (ms)
5530 47.4 10000 9952.6 Complied

Total Aggregate
Channel Frequency Channel Closing Limit Margin
Result
(MHz) Time after first (ms) (ms)
200 ms (ms)
5530 0.0 60 60.0 Complied

Page 14 of 24 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP11913492-2416C

VERSION 1.0 ISSUE DATE: 28 FEBRUARY 2018

5.2.2. Non-occupancy Period
Test Summary:

Test Engineer: Max Passell Test Date: 15 February 2018
Test Sample Serial Number: Not marked or stated (Conducted Sample)

FCC Reference: Part 15.407(h)(2)(iv)
Test Method Used: KDB 905462 D02 Section 7.8.3

Environmental Conditions:

Temperature (°C): 24
Relative Humidity (%): 41

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)(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. The noise floor remained below the -27 dBm/MHz spurious limit for the 30 minute (1800 seond) non-
occupancy period. Therefore the EUT is deemed to comply.

UL VS LTD Page 17 of 24

TEST REPORT SERIAL NO: UL-RPT-RP11913492-2416C

VERSION 1.0 ISSUE DATE: 28 FEBRUARY 2018

Non-occupancy Period (continued)
Results:

Channel Non-Occ Limit Margin
Trial Result
(MHz) (min) (min) (min)
5530 1 >34.4 30 >4.4 Complied

40

30

20

10
dBm

0

-10

-20

-30

-40
-30 270 570 870 1170 1470 1770 2070
Time / s

Level (dBm) End of Channel Move Time Non-occupancy Limit

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

Page 18 of 24 UL VS LTD

TEST REPORT SERIAL NO: UL-RPT-RP11913492-2416C

VERSION 1.0 ISSUE DATE: 28 FEBRUARY 2018

6. 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 of the measurand
(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 Calculated
Measurement Type Range
Level (%) Uncertainty
DFS Radar Amplitude 5.15 GHz to 5.825 GHz 95% ±2.17 dB
Channel Shutdown Timing 5.15 GHz to 5.825 GHz 95% ±0.45 ms
Non-Occupancy Timing 5.15 GHz to 5.825 GHz 95% ±79.25 ms

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.

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TEST REPORT SERIAL NO: UL-RPT-RP11913492-2416C

VERSION 1.0 ISSUE DATE: 28 FEBRUARY 2018

7. Report Revision History
Version Revision Details
Number Page No(s) Clause Details
1.0 - - Initial Version

UL VS LTD Page 21 of 24

Document Created: 2018-02-28 18:00:10
Document Modified: 2018-02-28 18:00:10

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