1. OTA Metrics and Methodology
January 2995
doc.: IEEE /1531r0
July 2005
Date:
OTA Metrics and Methodology
Authors:
Name
Company
Address
Phone
Fahd Pirzada
Dell
One Dell Way
Round Rock, TX 78682
Pratik Mehta
Neeraj Sharma
Intel
13290 Evening Creek Drive
San Diego, CA 92128
(858)
Uriel Lemberger
PO Box 1659, Matam Industrial Park, Haifa Israel
Sasha Tolpin
Nir Alon
Amer Hassan
Microsoft
One Msft Way Richmond, WA 98052
(425)
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Fahd Pirzada - Dell
Bruce Kraemer, Conexant

2. Agenda OTA Test Environments
July 2005
Agenda
OTA Test Environments
OTA in Shielded Enclosure
OTA Indoor NLOS
OTA Indoor LOS
OTA Outdoor LOS
OTA Throughput versus Attenuation in Shielded Enclosure
OTA Throughput versus Range in Indoor LOS Test Environment
Conclusion
Throughput versus Attenuation
Throughput versus Range
Fahd Pirzada - Dell

3. OTA in Shielded Enclosure
July 2005
OTA in Shielded Enclosure
Throughput numbers generated by end-to-end measurement tools e.g. using Chariot, Netperf, etc.
Turn-table allows averaging of throughput over various orientations
WLCP base line parameters defined in proposal: Max Tx Power, RTS threshold, QoS, etc.
Fahd Pirzada - Dell

4. Throughput versus Attenuation
July 2005
Throughput versus Attenuation
Total Setup Path Loss = Cable Losses Equipment Losses Free Space Path Loss
Attenuation (dB)
Direction of traffic flow (Downlink or uplink)
802.11a
Maximum Throughput (Mbps)
Minimum Throughput (Mbps)
Average Throughput
(Mbps)
Distance between DUT & Antenna (feet)
Total
Setup Path Loss (dB)
Downlink
19.03
17.87
18.49 32
58.2
Attenuation (dB)
Direction of traffic flow (Downlink or uplink)
802.11g
Maximum Throughput (Mbps)
Minimum Throughput (Mbps)
Average Throughput
(Mbps)
Distance between DUT & Antenna (feet)
Total
Setup Path Loss (dB)
Downlink
17.91
17.04
17.26 32
56.9
Fahd Pirzada - Dell

5. Throughput vs. Attenuation Data Variation
July 2005
Throughput vs. Attenuation Data Variation
Data collected on a off-the-shelf a/b/g NIC
Data collected at three different times with the same DUT
% variation = (Max Throughput – Min Throughput) / Avg. Throughput
Fahd Pirzada - Dell

6. OTA Indoor/Outdoor Test Environment
July 2005
OTA Indoor/Outdoor Test Environment
Traffic Generator
Wireless Counterpart
Device under Test
Upload
Obstruction
(if any)
Download
Turn Table
x meters
y meters
Test Parameters:
DUT test height
Location of DUT and WLCP
DUT lid/LCD angle
In-band noise
DUT XY placement accuracy
Consistent test equipment
DUT spinning
Climate
WLCP test height and orientation
The variability (error margin) between the three test runs is reported for each configuration tested.
This reported error margin should be below 5% for the first value of range (shortest distance between DUT and WLCP)
This reported error margin should be below 15% for the last value of range
Fahd Pirzada - Dell

7. Outdoor Throughput versus Range
July 2005
Outdoor Throughput versus Range
Range (feet)
Direction of traffic flow (Downlink or uplink)
Maximum g Throughput
(Mbps)
Minimum g Throughput (Mbps)
Average g Throughput
LOS or
non-LOS Environment
If non-LOS, details (number/type) about the obstructions 30
Downlink
15.83
13.42
14.39
LOS
Fahd Pirzada - Dell

8. Indoor non-LOS Data Variation (run-to-run)
July 2005
Indoor non-LOS Data Variation (run-to-run)
Data collected on a off-the-shelf a/b/g NIC
Data collected for 3 runs each time
% variation = (Max Throughput – Min Throughput) / Avg. Throughput
Mode
STA x
6 meters*, no obstructions
STA y
41 meters*, 0 walls, and 12 cubes
STA z
58 meters*, 3 walls, and 12 cubes
802.11b – Rx
0.94%
0.48%
0.28%
802.11b – Tx
0.15%
0.54%
0.11%
802.11g – Rx
0.45%
1.72%
1.77%
802.11g - Tx
0.21%
1.96%
1.54%
* Linear distance from the AP
Fahd Pirzada - Dell

9. Outdoor LOS Data Variation (run-to-run)
July 2005
Outdoor LOS Data Variation (run-to-run)
Data collected on a off-the-shelf a/b/g NIC
Data collected for 3 runs each time
% variation = (Max Throughput – Min Throughput) / Avg. Throughput
Mode
10 meters
50 meters
100 meters
200 meters
b - Rx
0.21%
0.07%
0.09%
1.41%
b - Tx
0.05%
0.03%
0.08%
1.74%
g - Rx
0.5%
0.07
5.84%
g - Tx
1.16%
0.10%
12.07%
* Linear distance from the AP
Fahd Pirzada - Dell

10. Conclusion Over-the-air (OTA) environments allows us to:
July 2005
Conclusion
Over-the-air (OTA) environments allows us to:
Evaluate antenna, device and overall system wireless performance
Perform comparisons between various systems
Perform correlation to real-life usage scenarios
We have done detailed testing in indoor/outdoor test environments to correlate our data from the OTA shielded enclosure setup
The results from indoor/outdoor testing provides acceptable level of repeatability within the same test environment
Fahd Pirzada - Dell