1. Wi-Fi interference measurements in Korea (Part II)
May 2013
doc.: IEEE /xxxxr0
Mar. 2014
Wi-Fi interference measurements in Korea (Part II)
Date:
Authors:
Name
Affiliations
Address
Phone
Minho Cheong
NEWRACOM
193 Moonjiro, Yuseong-Gu, Daejeon, Korea
Hyoung Jin Kwon
Jae Seung Lee
ETRI
Minho Cheong (NEWRACOM)
Osama Aboul-Magd (Huawei Technologies)

2. Mar. 2014
Abstract
This presentation gives set of additional measurement results of Wi-Fi interferences in Seoul metropolitan area, especially depending on the deployment density of Wi-Fi devices, which will be helpful for problem setting of HEW.
Minho Cheong (NEWRACOM)

3. Additional Path-loss due to Human Body Blockage [1]
Mar. 2014
Additional Path-loss due to Human Body Blockage [1]
In super-dense scenarios, in addition to general indoor (from n/ac channel model) or outdoor (from WINNER or ITU model), we need to consider the following environments as well AP
My STA
(smart phone)
Minho Cheong (NEWRACOM)

4. Measurement Campaign Measurement schedule & Measurement spot Equipment
Mar. 2014
Measurement Campaign
Measurement schedule & Measurement spot
Seoul Express Bus Terminal (indoor) in Seoul in January 2014
Equipment
AirMagent Wi-Fi Analyzer Pro, Mobile AP, Jperf Server
Measurement done on 2.4GHz (channel 9) by g
Measured DL PHY data rate from Laptop to mobile AP
Measured & analyzed DL MAC packets from Laptop to mobile AP
Mobile AP
Jperf server (wired)
Laptop
Minho Cheong (NEWRACOM)

5. Measurement Campaign (2)
Mar. 2014
Measurement Campaign (2)
Limitations on Measurements
So many moving people at all times
Not able to measure for a long time
because mobile AP used cannot hold large traffics
“AirMagnet Wi-Fi Analyzer”
can gather all the Wi-Fi data
Overall or per specific SSID or MAC address
can analyze all the statistics of Wi-Fi signals
Minho Cheong (NEWRACOM)

6. PHY Measurement results of DL traffic
Mar. 2014
PHY Measurement results of DL traffic
Measured DL packets from mobile AP to Laptop
Distance between them is 10m (in the middle of many people)
3 conditions tried per population density
all the other conditions same
0.05 people/m2 (very few), 0.25 people/m2(some people), 0.5 people/1m2 (crowded)
Mobile AP
Jperf server (wired)
Laptop
Average Rate
0.05 people/m2
0.25 people/m2
0.5 people/m2
PHY rate (Mbps)
15.045
6.281
1.391
# of packets/sec.
296.25
Minho Cheong (NEWRACOM)

7. MAC Measurement results of DL traffic
Mar. 2014
MAC Measurement results of DL traffic
3 conditions tried per population density
all the other conditions same
0.05 people/m2 (very few), 0.25 people/m2(some people), 0.5 people/1m2 (crowded)
The higher population density, the more controls & the less data frames
In addition, retry rate is highly sensitive due to different level of contentions
Packet types
0.05 people/m2
0.25 people/m2
0.5 people/m2
Control frame, ACK
36 %
57 %
63 %
Probe req./response
4 %
6 %
8 %
Data frame
55 %
31 %
23 %
Beacon & others
5 %
Retry rate
0.05 people/m2
0.25 people/m2
0.5 people/m2
11 %
12 %
24 %
Minho Cheong (NEWRACOM)

8. Mar. 2014
Conclusions
Measurements and analysis are done on dense Wi-Fi environments according to different level of population density
As population density goes high, performance of Wi-Fi goes extremely degraded
Due to much more contentions with devices near by
Due to additional path loss by human-body blockage for my signal
Solutions to dense Wi-Fi environments are strongly required so that we could also manage to use Wi-Fi in the future (explosion of number of Wi-Fi devices)
Minho Cheong (NEWRACOM)

9. Mar. 2014
References
[1] hew-channel-modeling-for-dense-Wi-Fi-environments
Minho Cheong (NEWRACOM)