doc.:11-14-1199-01-00ax

Submission

Sept 2014

Slide 1

Effect of CCA in residential scenario part 2

Date: 2014-09-15

Name Company Address Phone email Gwen Barriac Qualcomm 5775 Morehouse Drive

San Diego

Simone Merlin Qualcomm 5775 Morehouse Drive San Diego

George Cherian Qualcomm 5775 Morehouse Drive San Diego

Qingjiang Tian Qualcomm 5775 Morehouse Drive San Diego CA

Authors:

doc.:11-14-1199-01-00ax

Submission

Indroduction

• Multiple IEEE presentations have looked at the effects of CCA levels

– Several presentations have noted that higher CCAs have higher mean and 5% tputs than lower CCAs

• Note: Baselines of both CCA = -82 and CCA= -92 have been used

• At the June IEEE meeting, we presented results for various CCA levels using a reuse 1 residential scneario

– document 11-14-0846– We found that higher CCA levels were often harmful for the 5% point

• In this presentation we look at the residential scenario for reuse 3 and 6

September 2014

QualcommSlide 2

doc.:11-14-1199-01-00ax

Submission

Simulation Setting I• Residential Scenario

– IEEE residential scenario baseline• Less apartments modelled for faster run times

– Expect conclusions will not change

– 2x5x3 apartments– 30 APs

• 150 STAs (5 STAs per AP)

– Pathloss as specified in 11ax Simulation Scenarios document

– Reuse-3: 3x80 MHz channel– Reuse-6: 6x40MHz channel

• Note: all results are generated by simulating 80MHz BSS and then are appropriately scaled

– Results averaged over multiple random drops of APs and STAs locations

September 2014

QualcommSlide 3

Floor 1

Floor 2

Floor 3

Example of one drop

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Submission

Simulation Setting II

September 2014

QualcommSlide 4

• Simulation Details:– UL only Data traffic (+ DL ACKs)– Full buffer UDP– Default Tx Power: 20 dBm per antenna (AP), 15 dBm ( STA) – Antenna Gain: 0 dBi APs, -2dBi STAs– Rate Control:

• MCS per link chosen to maximize long term goodput – MAC modelling

• MAC is fully modelled• Deferral according to 11ah CCA rules

– OBSS packets deferral only if RSSI > ED (assume BSS ID (color) in PPDU• ED level controls deferral on a network level

• Nodes on the same 80 MHz channel have the same primary channel– PHY modelling

• Pathloss, shadowing, (pathloss as in SS document, shadowning w sd 5dB)• no fading. • Long term PER curves based on AWGN

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Submission

Reuse 3(Three channels: Red, Blue and Green)

• Channel Coloring: – No two APs that have the same

channel share a floor/wall

– For each AP, there are no more than 3 other APs that have the same channel and are within 2 (wall/floor)s penetration.

• Red Channel– AP =

[2,5,8,10,13,16,19,21,24,27]

• Blue Channel– AP =

[0,3,6,9 ,11,14,17,22,25,28]

• Green Channel– AP =

[1,4,7,12,15,18,20,23,26,29]

September 2014

QualcommSlide 5

2

5 8

10 13

16 19

21 24

27

0 3

6 9

11 14

17

22

25 28

1 4

7

12

15 18

20

26

23

29

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Submission

Reuse 3 results

• 5%ile• 3x improvements vs -92dBm

• 4x improvements vs -82dBm

• Mean• 30% increase vs -92dBm

• No gain compared to -82dBm

September 2014

QualcommSlide 6

UL 5 STAs per AP

CCA 5%tile 50%tile 90%tile mean

-52 1.58 35.61 78.82 38.72

-62 2.75 34.60 74.80 38.52

-72 3.88 36.44 82.21 39.79

-82 0.84 30.09 84.02 39.22

-92 1.21 18.23 80.03 29.57

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Submission

Reuse 3 results cont.

September 2014

QualcommSlide 7

• 5%ile– 7x increase vs CCA= -92dBm

– 3x increase if baseline is -82dBm

• Mean – 76% increase vs CCA= -92dBm

– 20%increase vs -82dBm

UL 1 STAs per AP

CCA 5% 50% 90% mean

-52 6.77 45.15 67.46 42.34

-62 7.42 46.62 67.53 43.36

-72 9.75 47.98 67.53 44.97

-82 3.12 35.57 67.31 37.50

-92 1.34 23.66 51.80 25.63

Note: Results in the table are divided by 5 so they can be compared to the 5 STA per AP case

doc.:11-14-1199-01-00ax

Submission

Reuse 6 (Six channels: Red, Blue, Yellow, Purple, Green and Gray)

• Channel Coloring:– No two APs that have the same

channel are within two floors/walls penetration

• Red Channel– AP = [6,9,10,13,27]

• Blue Channel– AP = [1,4,17,20,23]

• Green Channel– AP = [0,3,16,19,22]

• Yellow Channel– AP = [2,15,18,21,24]

• Purple Channel– AP = [5,8,12,26,29]

• Gray Channel– AP = [7,11,14,25,28]

September 2014

QualcommSlide 8

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Submission

Reuse 6 results

September 2014

QualcommSlide 9

UL 5 STAs per AP

• 5%ile– No gain if baseline is -82

– 4x gain if baseline is -92

• Mean: no difference

CCA 5% 50% 90% mean

-52 10.54 28.12 50.76 30.03

-62 10.34 27.50 51.86 29.80

-72 11.37 29.56 49.19 30.54

-82 12.49 29.49 49.25 30.73

-92 3.54 26.96 56.75 29.67

6 40 MHz channels

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Submission

Reuse 6 results cont.

• 5%ile – Significant improvement possible

compared to -92dBm baseline• In this scenario, some STAs suffer from the

‘exposed terminal’ issue when -92dBm is used

– No gain if baseline is CCA=-82dBm

• Mean– 20% gain by going from CCA=-92dBm to

anything else

• No gain if baseline is CCA -82dBm

September 2014

QualcommSlide 10

CCA 5% 50% 90% mean

-52 20.66 33.15 33.78 30.51

-62 20.90 33.67 33.79 30.67

-72 21.03 33.74 33.81 31.44

-82 20.95 33.74 33.80 31.94

-92 1.11 28.01 33.74 24.42

UL 1 STAs per AP

6 40 MHz channels

Note: Plots are obtained with 80MHz simulations, then result in the table are scaled to emulate 40MHz. Further they are divided by 5 just for easier comparison with the 5STA per AP case

doc.:11-14-1199-01-00ax

Submission

Conclusions

• For residential scenario reuse 1: – Increasing CCA can be harmful for the 5% throughput (from 11-14-0846)

• For residential scenario reuse 3:– Gains with increased CCA depend on what is assumed as baseline

• 5 STAs

– 5%ile: 3x improvements vs -92dBm; 4x improvements vs -82dBm

– Mean: 30% increase vs CCA=-92 to CCA= anything higher; No gain compared to -82dBm

• 1 STA

– 5%: 7x increase vs CCA= -92; 3x increase if baseline is -82

– Mean: 76% increase vs CCA= -92; 20%increase vs -82 dBm

• For residential scenario reuse 6– No gains by increasing CCA (except one special case)

• All CCA levels have good reuse

• Effects of changing the CCA levels is highly scenario and parameters dependent

September 2014

QualcommSlide 11