1. Power Consumption Measurement
doc.: IEEE /0008r1
January 2006
Power Consumption Measurement
Date: January, 2006
Authors:
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Alexander Tolpin, Intel
Alexander Tolpin, Intel

2. doc.: IEEE /0008r1
January 2006
Abstract
This document introduces the description of Power Consumption Measurement methodology and metric for performance testing of wireless LAN devices.
This presentations corresponds to the document t-Power-Consumption-Measurement-Proposal-Text.doc.
Alexander Tolpin, Intel
Alexander Tolpin, Intel

3. Summary Purpose Measurement Setup Operation States
doc.: IEEE /0008r1
January 2006
Summary
Purpose
Measurement Setup
Operation States
Measurement procedure
Example of measurement results
Conclusion
Alexander Tolpin, Intel
Alexander Tolpin, Intel

4. January 2006
Purpose
The basic measure of the average amount of a power that WLAN NIC consumes from the power supplier or the battery in different operation states.
This test is applicable to an infrastructure BSS client configurations as well as to standalone clients.
This is primary metric since impacts the end user experience such as battery life time.
Alexander Tolpin, Intel

5. January 2006
Test Setup
The setup for the measurement should be performed on one of two setups already defined in TGT draft [4] for throughput measurement.
The first is “Throughput versus attenuation in a conducted environment” described in [4] section 6.2. In this case the attenuation should be set in order to achieve the maximal TPT.
The second is the ”Throughput versus range in an OTA environment” already described in [4] section 6.6. In this case the range and orientation should be selected to achieve the maximal TPT, and the rotation of DUT should be omitted.
In both cases the entire system is suitably isolated from external interference and other unwanted signals.
Traffic Generator and Analyzer is used to measure TPT during the test and make sure the target TT is achieved.
The Digital Oscilloscope is used to measure voltage and average current in order to calculate average power consumption.
if DUT has more than one consuming line, each line shall be measured separately
each consuming line should be extended to allow connection of voltage and current probe
The Test Controller is connected to DUT, WLCP and Digital Oscilloscope for
Traffic generation and TPT measurement
Control of measurement of voltage, current and power consumption.
Alexander Tolpin, Intel

6. Power Consumption Measurement setup
January 2006
Power Consumption Measurement setup
Alexander Tolpin, Intel

7. Scheme of connection of voltage and current probes
January 2006
Scheme of connection of voltage and current probes
Alexander Tolpin, Intel

8. Operation States List Device Disabled. Idle unassociated.
January 2006
Operation States List
Device Disabled.
Idle unassociated.
Idle associated.
Wireless Disabled
Data Transfer RX
Data Transfer TX
Alexander Tolpin, Intel

9. Operation States Definition
January 2006
Operation States Definition
Device Disabled.
DUT is plugged in and installed on the platform but disabled by device manager.
Idle Unassociated.
DUT is enabled but it is not associated to any BSS or IBSS.
Represents the use case where DUT is turned on but so far there are no desired APs around.
Depends on how often and how long DUT performs scanning
Idle Associated.
DUT is associated to AP but there is no data exchange between AP and DUT except required management frames.
Represents the use case where a DUT is connected to an AP but not actively doing anything other then staying associated and ready to exchange data.
Alexander Tolpin, Intel

10. Operation States Definition (cont.)
January 2006
Operation States Definition (cont.)
Wireless Disabled.
DUT was already active and associated with AP but the radio of DUT currently is disabled.
Represents the use case where radio is turned OFF on the platform by GUI or special switch (a.k.a. HW RF-Kill)
HW RF-Kill isn’t always supported by platforms
Need to make sure this mode is supported and enabled.
Data Transfer RX.
DUT is associated to AP and mostly busy with receiving data
Represents the use case where DUT is fully loaded by running downstream at highest rate per band (54Mbps .11a/g & 11Mbps .11b)
Data Transfer TX.
DUT is associated to AP and mostly busy with transmitting data
Represents the use case where DUT is fully loaded by running upstream at highest rate per band (54Mbps .11a/g & 11Mbps .11b)
Alexander Tolpin, Intel

11. Measurement Procedure
January 2006
Measurement Procedure
The measurement procedure depends on the operation state; in general it looks as follows:
Set up DUT according to base configuration using initial test parameters with the best attenuation or the best range
Move DUT to the desired operation state
Generate the appropriate traffic if required; measure and report TPT
Measure voltage (V) simultaneously for each consumption line
Measure average current (I) simultaneously for each consumption line by the digital oscilloscope during 100Sec
Calculate the average power consumption as P=V*I for each consumption line separately
Combine results and report.
Alexander Tolpin, Intel

12. Example of current loops for 1.5V, 3.3V Main, and 3.3V AUX
January 2006
Example of current loops for 1.5V, 3.3V Main, and 3.3V AUX
Alexander Tolpin, Intel

13. Example of attachment of current probes to measure current and voltage
January 2006
Example of attachment of current probes to measure current and voltage
Alexander Tolpin, Intel

14. doc.: IEEE /0008r1
January 2006
Example of Power Consumption measurement results for different NICs in W
State
Band
TPT achieved (MBps)
NIC A (W)
NIC B (W)
NIC C (W)
NIC D (W)
Device Disabled
0.033
0.623
0.362
0.026
Idle Associated
0.070
0.810
0.354
0.073
Idle Not Associated
0.052
0.769
0.806
0.041
Wireless Disabled
0.035
0.027
Data Transfer Tx
11a 21
1.217
1.630
1.150
1.237
11g
1.117
1.705
0.960
1.086
11b 6
1.300
1.690
1.195
1.050
Data Transfer Rx
1.115
1.514
1.082
1.080
1.550
0.841
0.967
1.100
1.465
0.853
0.950
Alexander Tolpin, Intel
Alexander Tolpin, Intel

15. January 2006
Example of the chart of Power Consumption measurement results for different NICs in W
Alexander Tolpin, Intel

16. Conclusion The Power Consumption Measurement has been proposed
January 2006
Conclusion
The Power Consumption Measurement has been proposed
The proposal contains:
Purpose of the measurement
Descriptions of equipment and test setup
Description of operation states
Baseline, modifiers and test parameters
Calibration and precision requirements
Measurement Procedures
Reporting results requirements
Example
Recommendation:
Recommend TGT to adopt the content of document 11-06/0007r0 into the P draft.
Alexander Tolpin, Intel