1. Discussion on MAC Calibration Power Saving Test
July 2014
doc.: IEEE /xxxxr0
March 2015
Discussion on MAC Calibration Power Saving Test
Date:
Authors:
Yanchun Li (Huawei Technologies)
Osama Aboul-Magd (Huawei Technologies)

2. March 2015
Recap: Test 5 U-APSD
U-APSD which is suitable for bi-directional transmission has been selected by test 5 (Power Saving MAC Calibration) [1]
The scenario is revised in 2015 Jan meeting.
Yanchun Li (Huawei Technologies)

3. Theoretical Calculation of time in each state - STA Tx/Rx Time
March 2015
Theoretical Calculation of time in each state - STA Tx/Rx Time
Theoretical Calculation of time in each state - STA Tx/Rx Time
STA
Tx Time = 304us /40ms=0.76%
1 Data MSDU (236us) in each 40ms
ACK= 68us
Rx Time = Tx Time=0.76%
Operation
Value
MSDU
Data
120 bytes
MAC PDU
+ MAC Header 30 bytes
150 bytes
PHY SDU (A-MPDU: 1 MPDU per PHY SDU)
Ceiling((16 bit (Service Field)+ 4*8bit(Delimiter) + 150*8bit (MPDU)+ 2bit (Padding)+6bit (CC))/6.5e6,4e-6)
196 us
PHY PDU
+ 11ac PHY Header 40 us
236 us
Yanchun Li (Huawei Technologies)

4. Theoretical Calculation of time in each state - STA Tx/Rx Time
March 2015
Theoretical Calculation of time in each state - STA Tx/Rx Time
STA’s listen time per 40ms (217.5us/40ms= %)
100us (ProbeDelay)+( 34us(AIFS)+9us*15/2 (Backoff)+16us(SIFS) )*2 =335us
ProbeDelay
100 us
335 us (Listen Time per 40ms)
Channel Deferral
AIFS
34 us
117.5us in Total x2
=235 us
Random Backoff
9*15/2 us
SIFS
16 us
Yanchun Li (Huawei Technologies)

5. Theoretical Calculation of time in each state - STA Sleep Time
March 2015
Theoretical Calculation of time in each state - STA Sleep Time
STA Sleep Time
40ms (period)-304us (Tx Time)-304us(Rx Time)-335us(Listen Time) = 39057us
39057us /40ms=97.64%
Yanchun Li (Huawei Technologies)

6. Simulation results Simulation results matches the theoretical analysis
March 2015
Simulation results
Simulation results matches the theoretical analysis
MAC throughput: 29.6 kbps in both DL/UL, PER = 0%
Breakdown of percentage of time
STA (%)
AP (%)
time precentatge
Listen RX TX
Sleep
< Power Save Mechanism > On
Theoretical
0.84%
0.76%
97.64%
98.48%
0.00%
Simulation
< Power Save Mechanism > Off
*AP listens to the channel all the time (except TX and RX)
Yanchun Li (Huawei Technologies)

7. Breakdown of Power Consumption
March 2015
Breakdown of Power Consumption
Power consumption
STA (%)
AP (%)
Power Precentage
Listen RX TX
Sleep
< Power Save Mechanism > On
Theoretical
12.65%
22.96%
64.30%
0.09%
94.46%
1.46%
4.08%
0.00%
Simulation
< Power Save Mechanism > Off
- Energy Efficiency Ratio:
=0.0635
Yanchun Li (Huawei Technologies)

8. March 2015
Conclusions
Our MAC calibration test 5 U-APSD’s simulation results match with the theoretical analysis.
The energy efficiency ratio of U-APSD for delivering 120byte MSDU per 40ms in both UL and DL in ideal case is
Yanchun Li (Huawei Technologies)

9. Reference [1] 11-14-0980-06-00ax-simulation-scenarios.docx (2015 Jan)
March 2015
Reference
[1] ax-simulation-scenarios.docx (2015 Jan)
Yanchun Li (Huawei Technologies)

10. Recap: Power save test parameters in [1]
March 2015
Recap: Power save test parameters in [1]
Power save test parameters
AIFS=DIFS=34us
RTS/CTS [ OFF ]
MCS = [ 0 ]
Beacon is not transmitted in U-APSD test
Max SP Length = [ 4 ]
ProbeDelay = 100µs
Output:
MAC throughput
Percentage of time spent in each power state during the course of the simulation
Percentgae of energy consumed in each power state during the course of the simulation
Yanchun Li (Huawei Technologies)