### TPS13-020_rev1.2_Section-6-WiFi-Network-Optimization

```Altai Super WiFi
Altai Super WiFi
Altai Certification Training
WiFi Network Optimization
Professional Services
Altai Technologies Limited
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Not for Distribution – Altai Confidential
Module Outline
•
•
•
•
Altai Super WiFi
Altai Super WiFi
Problem
Coverage
Channel Usage and Capacity
Noise and interference
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Customer complain item
•
•
•
•
Altai Super WiFi
Altai Super WiFi
No coverage
Cannot connect
Low Throughput
Easily to lose the connection
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Reason
Altai Super WiFi
Altai Super WiFi
• Coverage issue
• Channel Usage and Capacity
• Noise or interference
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Altai Super WiFi
Altai Super WiFi
Coverage
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Coverage issue
Altai Super WiFi
Altai Super WiFi
How to find out
- Coverage mapping (drive test)
- Customer complain
- AP MCS statistic
Solution
- Adjust antenna direction, tilt or height to focus on
weak coverage location
- Adding C1n-C1n back to back pair
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AP MCS Statistic (Good)
Altai Super WiFi
Altai Super WiFi
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MCS Throughput Table
Altai Super WiFi
Altai Super WiFi
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Altai Super WiFi
Altai Super WiFi
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Coverage issue
Altai Super WiFi
Altai Super WiFi
How to find out
- Coverage mapping (drive test)
- Customer complain
- AP MCS statistic
Solution
- Adjust antenna direction, tilt or height to focus on
weak coverage location
- Adding C1n-C1n back to back pair
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Altai Super WiFi
Altai Super WiFi
• Increase antenna down tilt to focus on the nearby region and coverage.
• Scenario 1 (h =500m)
Original down tile = 500m, h = 80m
 =9
d = 500m, d1 = 290m, d2 = 1,479m
 =9 
h
Increase down tilt to 15
d = 298m, d1 = 198m, d2 = 500m
d
d1
d2
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Altai Super WiFi
Altai Super WiFi
• Increase antenna down tilt to focus on the nearby region and coverage.
• Scenario 1 (h =500m)
Original down tile = 500m, h = 80m
 =9
d = 500m, d1 = 290m, d2 = 1,479m
15
h
Increase down tilt to 15
d = 298m, d1 = 198m, d2 = 500m
d
d1
d2
Not for Distribution – Altai Confidential
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Coverage mapping result
Altai Super WiFi
Altai Super WiFi
Coverage
hole
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C1n back to back diagram
Altai Super WiFi
Altai Super WiFi
C1n back to back is that one C1n work as CPE (station) mode to connect to the
A8n/A8-Ein which maybe far away, then other C1n which will work as AP connect to the
C1n CPE via Ethernet cable and PoE adaptor provide the WiFi for the area where the
A8n/A8-Ein can not cover.
A8n/A8-Ein
C1n CPE
C1n AP
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C1n-C1n corner shop
Enhance coverage
Altai Super WiFi
Altai Super WiFi
Connect with A8Ein in tower
C1 CPE
C1 AP
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Altai Super WiFi
New A8Ein vs C1n CPE-C1n AP Altai
Super WiFi
New site configuration
Coverage
Increase total network capacity
Remote AWMS management
Site requirement
Backhaul
Power requirement
Hardware cost
Installation cost
Large
Yes
Yes
C1n CPE -C1n AP
Medium (Stree level)
No
Yes
Low (Corner shop or
High (Rooftop or tower)
lamp post)
Yes
No
Yes
Yes
Normal
Low
Normal
Low
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Altai Super WiFi
Altai Super WiFi
Channel Usage and Capacity
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Channel Usage from A8Ein
Altai Super WiFi
Altai Super WiFi
Tx + Rx < Busy %
The other AP and client occupy part of radio air time
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Channel Usage
Altai Super WiFi
Altai Super WiFi
How to find out
- From A8Ein Channel Usage Statistic
Continuous high channel usage (>90%) leads to low
user throughput, high latency.
The channel usage is by AP itself or other AP.
- AP itself -> capacity issue
- Other AP -> channel usage issue
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Channel Usage
Altai Super WiFi
Altai Super WiFi
Solution
- Change the frequency
- Adjust antenna direction, tilt or height to limit the
exposure of antenna from of AP traffic
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Frequency Scanning Result
Altai Super WiFi
Altai Super WiFi
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Capacity
Altai Super WiFi
Altai Super WiFi
Solution
- Adding new A8Ein in the same site
- With smaller coverage and focus on high user
density area
- AirFi
- It will increase the overall base station
throughput but not making every client happy
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Adding new A8Ein in same tower
Altai Super WiFi
Altai Super WiFi
35m
25m
New A8Ein to focus on smaller area to absorb traffic
200m
500m
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Altai Super WiFi
Altai Super WiFi
Noise and Interference
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Noise and Interference
Altai Super WiFi
Altai Super WiFi
2.4GHz is sharing band
Noise level increase as number of WiFi AP and
client increase. No particular source.
Interference is coming from particular source, e.g.
high power transmitter (non-standard compliance
device)
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Noise Level
Altai Super WiFi
Altai Super WiFi
Noise level is available from A8Ein Web GUI or
AWMS.
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Frequency Scan
Altai Super WiFi
Altai Super WiFi
Frequency scan to retune the frequency
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Interference
Altai Super WiFi
Altai Super WiFi
• Interference is coming from particular source, e.g. high
power transmitter (non-standard compliance device)
• Interference is very rare case. Nearly all cases in
undeveloped countries that many high power nonstandard compliance transmitter existed.
• Need to find out the interference source to eliminate or
avoid it.
• Handheld spectrum analyzer to locate the source.
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Normal 802.11n spectrum
Altai Super WiFi
Altai Super WiFi
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Spectrum for
audio video transmitter
Altai Super WiFi
Altai Super WiFi
3 peaks narrow band signal. Constant transmitting.
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Spectrum for
microwave oven
Altai Super WiFi
Altai Super WiFi
Very wide band and mountain shape. Continue for a few minutes.
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Interference - Solutions
Altai Super WiFi
Altai Super WiFi
Illegal transmitter or malfunction transmitter
- ask the owner to turn it off and fix it
Interference source cannot b eliminated -> avoid it
• turn AP antenna direction back to the interface
source
• metal grid between AP antenna and interference
source
• Move the antenna sites to other location
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Altai Super WiFi
Altai Super WiFi
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10.119.4.103
Altai Super WiFi
Altai Super WiFi
10.119.4.124
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Altai Super WiFi
Altai Super WiFi
Thank You
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QPSK and Phase relationship
Altai Super WiFi
Altai Super WiFi
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BPSK 16QAM
Altai Super WiFi
Altai Super WiFi
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Bit rate for modulation
Altai Super WiFi
Altai Super WiFi
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Altai A8Ein and C1n Rx Sensitivity
2.4 GHz
11b
MCS
11g
11b/g/n,
HT20,
SGI
0 (BPSK ½)
1 (QPSK ½)
2 (QPSK ¾)
3 (16QAM ½)
4 (16 QAM ¾)
5 (64QAM ½)
6 (64QAM ¾)
7 (64 QAM 5/6)
8 (BPSK ½)
9 (QPSK ½)
10 (QPSK ¾)
11 (16QAM ½)
12 (16 QAM ¾)
13 (64QAM ½)
14 (64QAM ¾)
15(64 QAM 5/6)
Data rate
1
2
5.5
11
6
9
12
18
24
36
48
54
7
14
22
29
43
58
65
72
14
29
43
58
87
116
130
144
Throughput
0.7
1.2
3
5
2
3
4
7
9
13
18
20
4
9
13
17
26
35
39
43
9
17
26
35
52
69
78
87
A8n Rx Sensitivity
-95
-94
-92
-90
-93
-93
-93
-92
-89
-85
-81
-80
-94
-93
-90
-87
-84
-81
-79
-77
-91
-90
-88
-84
-81
-78
-76
-74
C1n Rx Sensitivity
-96
-95
-94
-91
-94
-94
-94
-93
-90
-87
-83
-81
-94
-93
-91
-88
-85
-81
-79
-77
-93
-91
-88
-85
-82
-78
-76
-75
Not for Distribution – Altai Confidential
Altai Super WiFi
Altai Super WiFi
Higher the data rate,
Higher RX sensitivity
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Tools
Altai Super WiFi
Altai Super WiFi
• InSSider – Free, mapping and DL RSSI checking
• Fluke AirCheck
– Check DL Noise and SNR
– Check channel usage (incl. non-WiFi usage)
• MetaGeek Chanalzer
– For locating interference, very rare to use in
real operation
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```