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WSD Operations on the 1st Adjacent Channel
Laboratory and Field Measurements
Presentation to OET
28 JULY 2020
2020 TV WHITE SPACES NOTICE OF PROPOSED RULEMAKING
The Commission asks:
• Could more sophisticated computer models, such as Longley-Rice, be used to permit higher power unlicensed
operations on adjacent channels? If so, how? Are they sufficiently precise to identify areas where the desired TV
signal strength is sufficiently high that interference from adjacent channel white space devices is unlikely? What
specific technical parameters would need to be considered or specified in such calculations
• Is there any information available on adjacent channel selectivity and interference rejection capabilities of next
generation TV receivers, such as manufacturers’ specifications or actual measurement results? Is there any
indication that next generation TV receivers will in fact have better adjacent channel interference rejection than
current receivers?
• Are there other factors we can consider or steps that users or white space databases can take to provide for
more widespread use of white space devices near or within the contour of first adjacent television channels?
2
BACKGROUND
What do the FCC Rules and Report & Orders Say About fixed WSD operations on a 1st Adjacent Channel?
• OET-69 Planning Factors (1997 update) for DTV-into-DTV interference
o Desired-to-undesired (D/U) signal ratio on the co-channel: 15 dB to 23 dB [See 47 C.F.R. § 73.616(d)(1)(i)]
o Desired-to-undesired (D/U) signal rate on 1st adjacent channel: -26 dB (above) and -26 dB (below)
• ATSC A/74 Voluntary Standard: D/U = -33 dB when measured in the laboratory (no sideband splatter)
• WSD signals on the 1st adjacent channel have ‘noise like’ behavior as DTV-into-DTV interference: D/U= -33 dB
• Conducted adjacent channel emission limit in the first 100 kHz from the channel edge = Power6 MHz– 72.8 dBm
• DTV Receiver sensitivity: ATSC A/74 (-83 dBm) / FCC (-84 dBm)
• FCC Notice of Proposed Rule Making (2014) - Up to 4W EIRP for fixed WSDs on a channel offset by 3 MHz
• FCC Report and Order (2015) - 40 mW on 1st Adjacent Channel & 100 mW on a 3 MHz offset channel w/ a 10 m AGL limit
3
From the ‘Unlicensed Operation in the TV Broadcast Bands’
SECOND REPORT AND ORDER AND MEMORANDUM OPINION AND ORDER
(November 2008)
LABORATORY AND FIELD MEASUREMENT PROGRAM DESIGN
• Literature Review
• Lab Measurements
o Confirm receiver threshold signal level of select 2019 model ATSC 1.0 and ATSC 3.0 DTVs.
o Confirm D/U ratio on the co-channel, first adjacent channel, and on a channel that is offset by 3 MHz from the
edge of the broadcast channel for different desired signal levels.
• Field Testing
o Demonstrate that a simulated 34 dBm fixed WSD network can operate on the first adjacent channel without
causing harmful interference to select broadcast TV receivers.
o Validate the D/U values measured in the laboratory.
o Validate or disprove FCC 2008 uplink scenario.
4
LABORATORY SET-UP
EQUIPMENT USED• WSD - 6Harmonics 4000 Series Transmitter• ATSC 1.0 Exciter (DEKTEC DTU-315)• ATSC 3.0 Exciter (HITACHI-COMARK Exact V2)• AGWN Signal Generator – Rohde Schwartz• ATSC 1.0 DTV Receivers• ATSC 3.0 DTV Receivers• Video Quality Analyzer - AccepTv
DMOS and VMAF video quality scoring chart
MetricVideo Quality Scoring
Excellent Good Fair Poor Bad
DMOS 0 - 20 20 - 40 40 - 60 60 - 80 80 - 100
VMAF 100 - 80 80 - 60 60 - 40 40 - 20 20 - 0
5
DTVR ID Manufacturer Model Standard Profile Resolution Display Size
RX1 Samsung UN65NU8000 ATSC1.0 TV 4K 65 inch
RX2 TCL 55S517 ATSC1.0 TV 4K 55 inch
RX3 Hisense 40H3080E ATSC1.0 TV 1080p 40 inch
RX4 Samsung UN32N5300AFXZA ATSC1.0 TV 1080p 32 inch
RX5 Insignia NS-24DF310NA19 ATSC1.0 TV 720p 32 inch
RX6 Toshibha 32LF221U19 ATSC1.0 TV 720p 32 inch
RX7 LG OLED55B8PUA ATSC1.0 TV 4K 55 inch
RX8 Leelbox (D-A) ATSC DZ001 ATSC1.0 Set-up Box 1080p -
RX9 iDOO (D-A) Converter-0A ATSC1.0 Set-up Box 1080p -
RX10 Mediasonic (D-D) HOMEWORX HW130STB ATSC1.0 Set-up Box 1080p -
RX11 Lowasis LDA 1100/1200 ATSC3.0 USB Dongle UHD -
RX12 RedZone TVXPLORER BUNDLE ATSC3.0 USB Dongle HD -
ATSC 1.0 and ATSC 3.0 Receivers Selected
RX1 – RX7ATSC 1.0 DTV Receivers w/
integral screen
RX8 – RX10 ATSC 1.0 DTV Receivers w/o
screen
RX11-RX12ATSC 3.0 DTV
Receivers
6
DTV Receiver Type Threshold (dBm)
TV Signal
-43 dBm -53 dBm -65 dBm -80 dBm
D/U (dB)
RX1 -83.79 -40.55 -41.42 -42.19 -40.43
RX2 -87.78 -45.1 -45.01 -43.95 -42.30
RX3 -83.46 -45.97 -45.89 -45.39 -44.32
RX4 -82.52 -41.14 -42.06 -41.93 -40.28
RX5 -87.00 -47.46 -46.75 -45.75 -45.96
RX6 -83.45 -46.58 -45.94 -43.44 -45.87
RX7 -84.09 -44.91 -45.91 -42.78 -46.21
RX8 -86.94 -33.82 -38.75 -42.37 -40.91
RX9 -85.24 -35.76 -36.82 -38.21 -40.64
RX10 -87.18 -38.28 -40.64 -40.38 -40.88
ATSC 1.0 Receivers - D/U Ratio on the First Adjacent Channel
-43 dBm
-53
dBm-65 dBm
-80 dBm
7
DTV Receiver Type Threshold (dBm)
TV Signal
-43 dBm -53 dBm -65 dBm -80 dBm
D/U (dB)
RX1 -83.79 -46.35 -45.71 -45.01 -42.93
RX2 -87.78 -48.78 -48.40 -45.43 -46.07
RX3 -83.46 -49.56 -49.42 -47.87 -47.95
RX4 -82.52 -42.54 -42.06 -41.76 -40.24
RX5 -87.00 -47.46 -48.29 -46.75 -45.96
RX6 -83.45 -54.19 -55.36 -57.62 -56.54
RX7 -84.09 -53.23 -53.47 -52.78 -51.67
RX8 -86.94 -36.95 -46.13 -48.64 -45.58
RX9 -85.24 -47.38 -45.64 -49.03 -46.16
RX10 -87.18 -39.24 -43.21 -47.68 -49.80
ATSC 1.0 Receivers - D/U Ratio on the 3 MHz Offset Channel
-43 dBm
-53
dBm-65 dBm
-80 dBm
8
DTV Receiver Type
Threshold (dBm)
Modulation
TV Signal
-43 dBm
-53 dBm
-65 dBm
-80 dBm
D/U (dB)
UHD
-84.78 QPSK_7-
15_CodeRate -55.78 -56.10 -58.99 -59.61
-81.31 16QAM_7-
15_CodeRate -53.41 -54.06 -55.95 -48.56
-79.55 16QAM_11-
15_CodeRate -49.71 -49.74 -50.02 -39.84
-76.45 64QAM_11-
15_CodeRate -44.50 -45.07 -43.98 -36.49
-78.45 256QAM_7-
15_CodeRate -48.01 -46.84 -47.87 -38.83
HD
-84.78 QPSK_7-
15_CodeRate -61.03 -62.85 -64.18 -63.91
-81.31 16QAM_7-
15_CodeRate -55.07 -57.68 -58.58 -59.45
-79.55 16QAM_11-
15_CodeRate -43.25 -47.12 -47.85 -51.56
-76.45 64QAM_11-
15_CodeRate -45.24 -46.07 -47.29 -49.39
-78.45 256QAM_7-
15_CodeRate -42.91 -49.26 -52.08 -56.35
D/U Ratio for ATSC 3.0
DTV Receivers on the 1st
Adjacent Channel
9
DTV Receiver Type
Threshold (dBm)
Modulation
TV Signal
-43 dBm
-53 dBm
-65 dBm
-80 dBm
D/U (dB)
UHD
-84.78 QPSK_7-
15_CodeRate -59.92 -60.53 -60.36 -63.21
-81.31 16QAM_7-
15_CodeRate -57.09 -58.04 -57.72 -52.84
-79.55 16QAM_11-
15_CodeRate -53.76 -53.86 -54.51 -35.25
-76.45 64QAM_11-
15_CodeRate -49.95 -49.89 -49.48 -40.39
-78.45 256QAM_7-
15_CodeRate -49.87 -51.09 -47.86 -51.16
HD
-84.78 QPSK_7-
15_CodeRate -66.10 -69.00 -68.08 -70.13
-81.31 16QAM_7-
15_CodeRate -59.32 -59.18 -60.20 -61.13
-79.55 16QAM_11-
15_CodeRate -46.88 -47.60 -47.96 -49.05
-76.45 64QAM_11-
15_CodeRate -53.28 -55.07 -52.93 -49.94
-78.45 256QAM_7-
15_CodeRate -54.11 -54.06 -56.33 -52.37
D/U Ratio for ATSC 3.0
Receivers on the 3 MHz
Offset Channel
OBSERVATIONSOver time there has likely been an overall improvement in the D/U ratio on the
1st adjacent channel for DTV receivers – better adjacent channel selectivity
Selected RX4, RX10, and RX12 for the field tests
RX4 : Maximum power in first adjacent channel on the DTV tuner (signal threshold) that will not cause harmful interference
• (-82.5 dBm) – (-42.0 dB) = -40.5 dBm
RX10: Maximum power in first adjacent channel on the DTV tuner (signal threshold) that will not cause harmful interference
• (-87.2 dBm) – (-40.5 dB) = -46.7 dBm
RX12: Maximum power in first adjacent channel on the DTV tuner (signal threshold) that will not cause harmful interference
• (-78.4 dBm) – (-47.3 dB) = -31.2 dBm
Compare with
10
KTWC-LDChannel 34
Crockett, Texas
L-R Plot from RabbitEars.com website in dBu
11
FIELD TESTING
• Grapeland, Texas was established as the measurement area based on:
o a willing broadcast partner and sufficient available channels
o coverage maps using F-curves and Longley-Rice models predict field strength in the
moderate to weak signal range
o availability of a suitable tower within KTWC’s protected contour; and
o a representative community for fixed WSD use.
TEST PROCEDURE
• 24 test points (original test plan more ambitious). The
WSDs operated on channel 35.
• A ‘home’ with an outdoor DTV antenna was simulated
with a van towing a trailer that would allow the Yagi
antenna to be adjusted to 10 meters AGL. At each test
point, the antenna was oriented to maximize the
received DTV signal.
• WSD Base Station(s) on tower at 30, 60, and 85 meters
above level to examine effects of terrain. The WSDs
operated at a conducted power of 23 dBm. A 90-
degree panel antenna with 11 dBi antenna was used.
• A ‘home’ with a WSD CPE was simulated with a van
towing a trailer that would allow the 10 dBi LPDA
antenna to be adjusted to 10 meters AGL. At each test
point, based on the Nominet WAVEdB modeling for
channel 36, the orientation of the CPE was optimized.
12
Grapeland, Texas Test Points and DTV Signal Strength
Test points ranged between 19.5 and 23.8 km away from the DTV transmitter and 0.5 – 3.6 km from the WSD tower.
13
TEST PROCEDURE
Once the site was documented and a background scan completed, the following steps were performed:
• DTV and TVWS system installed as shown in the Block Diagram of Field Test Set-up (slide 15).
• Disabled ATSC 1.0 or ATSC 3.0 DTV signal transmission and performed background noise measurement using a spectrum
analyzer on channel 34 (590 – 596 MHz) and channel 35 (596 – 602 MHz).
• DTV broadcast station operated on channel 34 (590 – 596 MHz). Measured the received DTV signal at DTVR receiver.
• Configured TVWS base station (30m height AGL) on channel 35 (596 – 602 MHz) and associated CPE to complete
application level connectivity.
• Initiated traffic from between CPE and base station in uplink and downlink standalone. Measured the TVWS signal level
at the input of DTVR.
• Quantified video quality on the DTVR.
• Repeated the test combination for antenna height of 60m AGL and 85m AGL.
• Repeated measurement across all DTV receivers supporting ATSC 1.0 and ATSC 3.0 standards.
14
Field Measurement Set Up
15
Predicted DTV Field Strength Using F-Curves and Measured Field Strength at the DTV Antenna
Test Point
Distance
to DTV Tower (km)Predicted Field Strength
at DTV Antenna
using F-Curves
(dBm)
Predicted Field Strength
at DTV Antenna
using Longley-Rice
(dBm)
Measured Field Strength
at DTV Antenna
(dBm)
1 23.5 -38.73 -42.22 -56.6
4 23.8 -38.99 -43.23 -56.3
9 23.0 -38.29 -44.04 -56.1
10 23.0 -38.29 -44.10 -65.3
67 20.6 -36.15 -43.32 -62.4
68 19.5 -35.15 -57.92 -61.8
77 22.5 -37.84 -43.36 -56.8
78 22.5 -37.84 -43.33 -58.7
81 22.5 -37.84 -42.93 -66.7
83 22.0 -37.40 -43.14 -50.1
86 21.9 -37.31 -41.74 -57.2
89 22.5 -37.84 -43.54 -65.8
95 22.2 -37.58 -43.61 -59.3
97 22.4 -37.76 -43.62 -59.7
98 21.9 -37.31 -41.61 -61.7
100 21.9 -37.31 -41.60 -58.3
101 22.0 -37.40 -42.74 -66.8
102 22.9 -38.20 -43.23 -59.0
104 21.4 -36.86 -41.92 -60.9
105 21.4 -36.86 -43.69 -50.7
106 21.4 -36.86 -44.25 -54.2
110 21.2 -36.69 -40.04 -54.8
111 21.6 -37.04 -41.37 -60.8
114 21.1 -36.60 -41.06 -51.4
16
Test Point 4: Farm-to-Market Rd. 228 and El Camino
Terrain Profile of TVWS Link at Test Point 4
for Base Station at 30 m AGL
Terrain Profile of TVWS Link at Test Point 4
for Base Station at 60 m AGL
Terrain Profile of TVWS Link at Test Point 4
for Base Station at 85 m AGL
17
Test Point Distance to TVWS Tower
(km)
Desired DTV Signal at the RX4 and RX10 DTVR
(dBm)
Undesired Downlink TVWS Signal at the RX4 and RX 10 DTVR
(dBm)
1 2.804 -58.6 -76.6
4 3.43 -64.3 -76.3
9 2.361 -64.1 -82.3
10 2.645 -73.3 -83.4
67 2.82 -70.4 -85.0
68 3.588 -69.8 -85.2
77 1.906 -64.8 -80.0
78 2.139 -66.7 -76.1
81 2.048 -74.7 -81.2
83 1.789 -58.1 -80.9
86 1.906 -65.2 -80.9
89 1.653 -73.8 -81.7
95 1.219 -67.3 -81.1
97 1.758 -67.7 -81.2
98 1.029 -69.7 -81.4
100 1.112 -66.3 -76.3
101 1.526 -78.4 -76.6
102 1.565 -67.0 -76.6
104 0.797 -68.9 -69.4
105 0.629 -58.7 -64.7
106 0.462 -62.2 -66.7
110 1.363 -62.8 -76.3
111 1.728 -68.8 -76.3
114 1.304 -59.4 -75.3
Measured Desired and Undesired Signal at the DTV Receiver for RX 4 and RX 10
18
Test Receiver RX4 Receiver RX10
Point DL UL DL UL
1 - - - Impairment at 60m
4 - - - -
9 - - - -
10 - - Impairment at 60m Impairment at 60m, 85m
67 - - - -
68 - Impairment at 60 m - Impairment at 60m, 85m
77 - - - -
78 - - - -
81 - - - -
83 - - - -
86 - - - -
89 - - - -
95 - - - Impairment at 60m
97 - - - -
98 - Impairment at 60 m - Impairment at 60m
100 - - - -
101 - - - -
102 - - - Impairment at 85m
104 - - - -
105 - - - -
106 - - Impairment at 30m -
110 - - Impairment at 30m, 60m, 85m Impairment at 30m, 60m, 85m
111 - - Impairment at 85m -
114 - - Impairment at 60m, 85m Impairment at 60m
Test Points and WSD Heights Where Impaired Video Was Observed for RX4, RX10, and RX12
• 1-minute observation period each
• 360 measurements –o 24 (Test Points) x o 3 (TVWS Base Station Heights) x o 2 (Type of ATSC 1.0 receivers) x o 2 (Uplink and Downlink)
• 22 instances of pixilation • (defined as => 1-pixel loss)
o 20 ATSC 1.0 D-D Set Top Boxo 2 ATSC 1.0 DTV receiver o 0 ATSC 3.0
• DTV receiver pixilation could not be reproduced
• Test point 110 was under power lines.
19
Test Point
Direction Antenna Height
Impairments DMOS3 VMAF4
Duration (s) Frequency Visible on Screen
RX4
68 UL 60m <1 Once Yes - -
98 UL 60m <1 Once Yes - -
RX10
1 UL 60m <1 Once Yes 5.52 93.26
10
DL 60m 1 Once Yes 19.34 80.53
UL 60m <1 Once Yes 9.26 89.55
UL 85m <1 Once Yes 8.23 91.08
68 UL 60m 1 Once Yes 7.68 92.04
UL 85m 1 Once Yes 9.11 89.88
95 UL 60m 2 Once Yes 24.58 71.38
98 UL 60m <1 Once Yes 11.55 87.56
102 UL 85m <1 Once Yes 11.55 87.55
106 DL 30 m 2 Once Yes 24.56 79.82
110
DL 30m >30 Whole Video Yes 83.97 6.88
DL 60m >30 Whole Video Yes 85.21 6.32
DL 85m >30 Whole Video Yes 84.73 6.59
UL 30m 5 Once Yes 69.55 10.23
UL 60m 5 Once Yes 65.22 11.05
UL 85m 4 Once Yes 62.89 11.83
111 DL 85m <1 Once Yes 12.56 84.17
114
DL 60m 3 Once Yes 31.88 72.56
DL 85m 2 Once Yes 29.62 75.17
UL 60m <1 Once Yes 6.55 93.57
Rating DMOS VMAF
Excellent 0 100
Good 20 80
Fair 40 60
Poor 60 40
Bad 80 20
100 0
Image Quality of Impaired Videos
• All impairments were visible on TV screen
• Except for Test Location 110, image pixilation was
observed only once
• Image quality for impairments lasting up to a second is
between good to excellent
• Image quality for impairments lasting between one and
three seconds is fair to good
• Believe the noise from the power lines at TL 110 caused
interference in the D-D Set Top Box
• Believe the remainder of the impairments are caused
by impulse / ambient noise sources in environment
20
• Test Location 95
• D-D Set Top Box (RX10)
• TVWS radio is 60 meters above ground level
• Fair-to-good image quality
21
BREAKPOINT TEST TO VALIDATE D/U RATIO OBTAINED IN LAB MEASUREMENT
RF cable
Ethernet cable
WSD Tower DTV Tower
22
BREAKPOINT TEST
DTV
Receiver
DTV
Signal at
DTVR
(dBm)
WSD
Power
at
DTVR
(dBm)
Visual
Impact
Observed
in the
Field
DTV
Receiver
D/U as
measured
(dB)
Predicted
Maximum
WSD Power
on DTVR
without
causing
visual
artifacts
(dBm)
Difference
Between
Measured Field
and Lab
Maximum TVWS
Level (dB)
RX4 -68.9 -39.9 No
IMPACT
-41.93 -40.5 0.6
-36.4 IMPACT -41.93 -40.5 4.1
RX10 -68.9 -48.3 No Impact -40.83 -46.7 -1.6
-45.4 IMPACT -40.83 -46.7 1.3
RX12 -65.4 -29.3 No Impact -47.87 -31.2 1.9
-65.4 -28.1 IMPACT -47.87 -31.2 3.1
23
16 Meter Uplink Test (from the 2008 2nd R&O)
Test Location DTV Signal at DTVR
(dBm)
TVWS CPE
Conducted Power
(dBm)
TVWS CPE
Radiated Power
(dBm)
TVWS Signal at DTV
Receiver
(dBm)
TVWS Throughput
(Mbps)
Visual Impact Observed in
the Field
105 -68.7 23 33 -70.8 9.6 No impact
-68.8 23 33 -79.5 2.4 No impact
Used DTV and TVWS antennas in their respective trailers to simulate the following geometry
WSD
CPE
DTV
Tower
WSD
BS
---16m--
24
OBSERVATIONS
• The measured DTV field strength at the DTV receiver is considerably lower than that predicted by use of the F-curves and the
free space path loss (FSPL) model. The terrain-based model was still optimistic compared to the measured value but several
dBm less so than the F-Curves and the FSPL model.
• The measured WSD Base Station signal at the DTV receiver is considerably lower than that received by the nearby CPE. Cross-
polarization loss was identified as a potential significant loss mechanism. Depending on the alignment of the DTV antenna
vis-à-vis the WSD tower, there could be significant cross polarization loss between the horizontally polarized DTV signal and
vertically polarized WSD signal. More significant for uplink.
• The D/U ratios for the three receivers established through laboratory experiments were validated in the field.
• For the ATSC 1.0 DTV receiver (with integral display) there was one instance of impairment observed at 2 of the 24 test
points, each lasting a second, which represents 0.02 percent of total measurement time of 8640 seconds. The impairments
could not be reproduced.
• For the ATSC 1.0 Set-Top box, 20 incidences of impairments were observed at 10 test points. Outside of the test point under
the power lines, the recorded video for 10 of the occurrences registered image quality in the good-to-excellent range and 4
of the occurrences registered image quality in the fair-to-good range.
• There were no instances of visual impairment observed with the ATSC 3.0 receiver.
25
2020 TV WHITE SPACES NOTICE OF PROPOSED RULEMAKING
The Commission asks:
• Could more sophisticated computer models, such as Longley-Rice, be used to permit higher power unlicensed
operations on adjacent channels? [YES, LR should be used instead of the F-curves for all fixed WSD
calculations]If so, how? Are they sufficiently precise to identify areas where the desired TV signal strength is
sufficiently high that interference from adjacent channel white space devices is unlikely? [See below] What
specific technical parameters would need to be considered or specified in such calculations [Fixed WSD
antenna information, terrain, cell size]
• Is there any information available on adjacent channel selectivity and interference rejection capabilities of next
generation TV receivers, such as manufacturers’ specifications or actual measurement results? [YES] Is there any
indication that next generation TV receivers will in fact have better adjacent channel interference rejection than
current receivers? [YES]
• Are there other factors we can consider or steps that users or white space databases can take to provide for
more widespread use of white space devices near or within the contour of first adjacent television channels?
[Cross-polarization loss]
26
Proposals for High Power First Adjacent and 3 MHz Offset Channel
1) Downlink TVWS operations only on the first adjacent channel at up to 34 dBm EIRP, bonded to or
aggregated with a bi-directional TVWS channel, within an annular coverage area defined by the
WSDB.
2) Uplink and downlink TVWS operations on a channel that is offset by 3 MHz from the broadcast
channel within the annular coverage area.
3) Uplink and downlink TVWS operations at up to 36 dBm EIRP in any 500-meter by 500-meter cells
identified by the WSDB as permissible using a terrain-based model within the proposed coverage
area. Possibly reduce modeled desired signal level by some amount to compensate for a somewhat
over optimistic model closer to the DTV transmitter.
27
41 dBuDTV Noise Limited Service
48 dBuMinimum Field Strength over Community of License
DTV Transmitter
Strong Desired DTV Signal (> -28 dBm)
90 km
103 km
From 47 C.F.R. § 73.622(f)(8)(i)
Table – Max allowed EIRP and Antenna
Height for DTV Stations on channels 14-
59, all zones
ERP = 1000 kW, HAAT = 365 m
TVWS NetworkRadius = 11 km
Proposal (1): Downlink WSD operations only on the first adjacent channel at up to 34 dBm EIRP, bonded to, or aggregated, with a bi-directional TVWS channel, within an annular coverage area defined by the WSDB.
Not drawn to scale
WSD BASE STATION TRANSMIT ANTENNA (SL12948B)
Vertical Antenna PatternHorizontal Antenna Pattern
29
THANK YOU
For additional questions on the laboratory and field measurements please contact:
Michael Daum ([email protected])
Bryan Mikesh ([email protected])
Vern Fotheringham ([email protected])
30
