1. Simulation results for
January 2015
Simulation results for
Box 5 calibration
Date:
Authors:
Name
Affiliations
Address
Phone
Suhwook Kim
LG Electronics
19, Yangjea-daero 11gil, Seocho-gu, Seoul , Korea
Wookbong Lee
Giwon Park
Jeongki Kim
Kiseon Ryu
HanGyu Cho
Suhwook Kim, LG Electronics

2. January 2015
Abstract
This submission provides updated simulation results for Box-5 calibration
We updated simulator based on 1523r2 which was agreed in November meeting [4]
Suhwook Kim, LG Electronics

3. Box-5 Calibration [1] Box 0, 1, and 2 calibration are almost done
January 2015
Box-5 Calibration [1]
Box 0, 1, and 2 calibration are almost done
Box 3 calibration is now in progress
Box 5 calibration was initially discussed in previous meeting
Box 5: Integrated system simulator calibration
The objective is to align a combination of all PHY and MAC features
Suhwook Kim, LG Electronics

4. Box-5 PHY Details [2] January 2015 PHY parametersBW
All BSSs at 5GHz [80 MHz, no dynamic bandwidth]
Channel model
TGac D NLOS per link
Shadow fading
iid log-normal shadowing (5 dB standard deviation) per link
Data Preamble Type
[5GHz, 11ac], always decoded correctly after successful reception, duration is considered.
STA TX Power
15 dBm per antenna 
AP TX Power
20 dBm  per antenna
AP number of TX/RX antennas
1/1
STA number of TX /RX antennas
AP antenna gain
0 dBi
STA antenna gain
-2 dBi
Noise Figure
7dB
CCA threshold
-70dBm (measured across the entire bandwidth after large-scale fading)
Rx sensitivity
-82dBm (a packet with lower rx power is dropped)
Link Adaption
Fixed MCS =7 (292.5 Mbps)
Channel estimation
ideal
PHY abstraction
RBIR, BCC [1, 5]
Channel correlation
Independent or time-correlated channel per packet
Suhwook Kim, LG Electronics

5. Box-5 MAC Details [2] January 2015 100 drops per simulation
MAC parameters
Access protocol
[EDCA, AC_BE with default parameters] [CWmin = 15, CWmax = 1023, AIFSn=3 ]
Queue length
A single queue for each traffic link is set inside AP/STA sized of 2000 packets
Traffic type
UDP CBR with rate 10^8bps (may not enough to model full buffer)
MPDU size
1540 Bytes (1472 Data + 28 IP header + 40 MAC header)
Aggregation
[A-MPDU / max aggregation size / BA window size, No A-MSDU, with immediate BA], Max aggregation: 64 MPDUs with 4-byte MPDU delimiter
Max number of retries 10
Beacon
Disabled
RTS/CTS
OFF
Traffic direction
UL Only, DL only
Throughput metric
CDF or Histogram of per non-AP STA throughput (received bits/overall simulation time)
100 drops per simulation
1 drop = 5 seconds (+ 1 second for initial running)
Suhwook Kim, LG Electronics

6. 11ac Scenario 6 – OBSS Enterprise [2][3]
January 2015
11ac Scenario 6 – OBSS Enterprise [2][3]
Fixed Location and Association
STA1
(5,-9.5)
STA2
(3.5,7.5)
STA4
(-4.5,0.5)
STA5
(-1.5,6)
STA7
(-9,-5)
STA8
(-8.5,8.5)
STA10
(-3,0.5)
STA11
(-0.5,8)
STA13
(-4,-4)
STA14
(7.5,-1)
STA16
(8,-6)
STA17
(0,-7.5)
STA19
(-2.5,-4.5)
STA20
(0.5,-2)
STA22
(0,-4.5)
STA23
(-1.5,7)
STA25
(3.5,-5)
STA26
(9,9.5)
STA28
(-8,-5.5)
STA29
(1.5,3.5)
AP A
(0,0)
AP B
(40,20)
AP C
(-40,-20)
STA3
(7.5+xb, ‑9.5+yb)
STA9
(7+xb, -7.5+yb)
STA15
(3+xb, -0.5+yb)
STA21
(-6.5+xb, -3+yb)
STA27
(‑6+xb, 2.5+yb)
STA6
(-5.5+xc,4.5+yc)
STA12
(7+xc,7+yc)
STA18
(10+xc,0.5+yc)
STA24
(3+xc,2.5+yc)
STA30
(9.5+xc,3.5+yc)
Suhwook Kim, LG Electronics

7. Traffic Flow Model [2][3]
January 2015
Traffic Flow Model [2][3]
DL/UL traffic assigned for each STA
STA DL UL
STA1 y
STA23 n
STA2
STA25
STA4
STA26
STA5
STA28
STA7
STA29
STA8
STA3
STA10
STA9
STA11
STA15
STA13
STA21
STA14
STA27
STA16
STA6
STA17
STA12
STA19
STA18
STA20
STA24
STA22
STA30
Suhwook Kim, LG Electronics

8. Updated simulator Take the whole preamble as a standalone sub-frame
January 2015
Updated simulator
Take the whole preamble as a standalone sub-frame
Preamble decoding modeled as a sub-frame decoding
Preamble is legacy + VHT in Data frame and only legacy in Control frame
Legacy + VHT: decoding depends on VHT-SIG-A
Legacy only: decoding depends on L-SIG
RBIR-based PHY abstraction
Each MPDU is decoded individually by weakest link (Option 2)
Control frame
Opt 2: decoding error modeled as a sub-frame decoding
Take the whole control frame as a standalone sub-frame
For calibration, MCS0 is used for control frames
Suhwook Kim, LG Electronics

9. Updated simulator - continued
January 2015
Updated simulator - continued
Receiver will be locked by the first-arrived packet, and later-arrived packets are considered as interference
i.e. window size = 0 (for calibration)
If preamble passes, the receiver continues to receive the rest part of the packet, i.e., to decode each MPDU;
If successfully decoding of a control frame, defer for NAV;
Otherwise, set CCA to busy for the entire PPDU duration if rx power higher than rx sensitivity (=CCA-SD)
If preamble fails, the receiver terminates current reception
The entire PPDU fails
The receiver is unlocked again and CCA-ED threshold is used to determine if the medium is busy.
Suhwook Kim, LG Electronics

10. One BSS Test Result BSS B (STAs 3, 9, 15, 21, 27)
January 2015
One BSS Test Result
BSS B (STAs 3, 9, 15, 21, 27)
UL only & DL only, UDP CBR with rate 10^8bps
Total Tput
UL: Mbps
DL: Mbps
Suhwook Kim, LG Electronics

11. One BSS Test Result Comparison with old version result January 2015
DL only
UL only
Old version simulator
New version simulator
STA3
50.58
51.05
(+0.47)
36.63
36.83
(+0.20)
STA9
50.59
50.97
(+0.38)
42.11
39.86
(-2.25)
STA15
50.64
51.11
48.67
48.95
(+0.28)
STA21
50.46
50.70
(+0.24)
44.74
42.00
(-2.74)
STA27
50.56
51.10
(+0.55)
45.80
39.01
(-6.79)
Sum
252.83
254.93
(+2.10)
217.95
206.66
(-11.30)
Suhwook Kim, LG Electronics

12. One BSS Test Result BSS B (STAs 3, 9, 15, 21, 27)
January 2015
One BSS Test Result
BSS B (STAs 3, 9, 15, 21, 27)
Mixed DL&UL, UDP CBR with rate 10^8bps
Total Tput:
Mbps
UL: Mbps
DL: Mbps
Suhwook Kim, LG Electronics

13. January 2015
Observations
New DL throughput results show very similar with old version
Major change is receiving procedure in collision, however, there is no collision in DL only case
Mixed DL&UL looks simply addition and scaling of DL only and UL only
DL throughput: Mbps → Mbps (87%↓)
UL throughput: Mbps → Mbps (19% ↓)
note: 5/6=0.83, 1/6=0.17
Suhwook Kim, LG Electronics

14. January 2015
Observations
On the other hand, some STAs show different UL throughput from old version
Location of each STA may be key factor of this difference
All STA can be hidden from others because of channel variation
Following parameters may be useful to analyze collision events
# of Interferer frames transmitted by STAi
pd, i =
x 100
# of total frames transmitted by STAi
# of success subframes transmitted by STAi
psucc, i =
x 100
# of Interfered frames transmitted by STAi
# of total subframes transmitted by STAi
pr, i =
x 100
# of total frames transmitted by STAi
Suhwook Kim, LG Electronics

15. January 2015
Observations
Throughput
pd, i
pr, i
psucc, i
STA3
36.83 Mbps
6.30 %
6.27 %
60.6 %
STA9
39.86 Mbps
5.93 %
5.90 %
63.6 %
STA15
48.95 Mbps
4.55 %
4.58 %
70.2 %
STA21
42.00 Mbps
5.53 %
5.49 %
64.5 %
STA27
39.01 Mbps
6.07 %
6.16 %
62.6 %
All station occasionally suffers from interference caused by hidden terminal
Generally probability is higher as distance is longer
Direction also affects the interference probability
Suhwook Kim, LG Electronics

16. Three BSSs Test UL only January 2015 BSS C Total Tput: 148.61 Mbps
BSS B
Total Tput:
Mbps
BSS A
Total Tput:
83.84 Mbps
Suhwook Kim, LG Electronics

17. Three BSSs Test DL only January 2015 BSS B Total Tput: 178.01 Mbps
BSS C
Total Tput:
Mbps
DL only
BSS A
Total Tput:
15.87 Mbps
Suhwook Kim, LG Electronics

18. Three BSSs Test Result Comparison with old version result January 2015
UL only
DL only
Old version simulator
New version simulator
BSS A
61.88
83.84
(35% ↑)
75.22
15.87
(79% ↓)
BSS B
99.29
112.87
(14% ↑)
117.24
178.01
(52% ↑)
BSS C
115.47
148.61
(29% ↑)
110.15
172.28
(56% ↑)
Sum
276.64
345.32
(25% ↑)
302.61
366.16
(21% ↑)
Suhwook Kim, LG Electronics

19. Observations In UL only case, all BSS shows better performance
January 2015
Observations
In UL only case, all BSS shows better performance
Especially, BSS A shows the largest performance enhancement
In DL only case, all BSS except BSS A shows better performance
BSS A has very poor performance (almost 80% degradation)
Areal performance is improved by at least 20% from old version
Following parameters will be used for analysis
total idle time sensed by APi
# of total frames transmitted by APi
It, i =
x 100
Nt, i =
total simulation time (500 sec)
total simulation time (500 sec)
# of subframes transmitted by APi
# of success subframes transmitted by APi
x 100
AVERf, i =
psucc, i =
# of frames transmitted by APi
# of total subframes transmitted by APi
Suhwook Kim, LG Electronics

20. Observations In DL only case
January 2015
Observations
In DL only case
BSS B and C are frequently divided spatial domain
Between BSS B and C, channel is almost BUSY whenever AP A senses channel, so AP A couldn’t get TXOP easily
Number of subframes in one AMPDU is smaller in BSS A
It affects the throughput performance
Also direction (location) of stations is consideration factor
Throughput
Nt, i
It, i
AVERf, i
psucc, i
BSS A
15.87 Mbps
67.2
0.74 %
28.5
64.7 %
BSS B
Mbps
598.7
3.73 %
31.8
82.3 %
BSS C
Mbps
600.4
3.61 %
31.6
74.8 %
Suhwook Kim, LG Electronics

21. January 2015
Conclusion
In this submission, we provided updated simulation results for Box 5 calibration
Suhwook Kim, LG Electronics

22. Reference [1] 11-14/0571r5 Evaluation Methodology
January 2015
Reference
[1] 11-14/0571r5 Evaluation Methodology
[2] 11-14/1177r2 Box5 Calibration Discussion
[3] 11-09/0451r16 TGac Functional Requirements and Evaluation Methodology
[4] 11-14/1523r2 Offline Discussion Minutes of SLS Calibration
Suhwook Kim, LG Electronics