doc.: IEEE 11-14/0112r1

Submission

Mar. 2014

Minho Cheong (NEWRACOM)Slide 1

Wi-Fi interference measurements in Korea (Part II)

Date: 2014-03-17

Authors:

Name Affiliations Address Phone emailMinho Cheong NEWRACOM 193 Moonjiro,

Yuseong-Gu, Daejeon, Korea

+82-42-860-5635 minho.cheong@newracom.com

Hyoung Jin Kwon NEWRACOM 193 Moonjiro, Yuseong-Gu, Daejeon, Korea

+82-42-860-1698 hj.kwon@newracom.com

Jae Seung Lee ETRI jasonlee@etri.re.kr

doc.: IEEE 11-14/0112r1

Submission

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.

Mar. 2014

Slide 2 Minho Cheong (NEWRACOM)

doc.: IEEE 11-14/0112r1

Submission

Additional Path-loss due to Human Body Blockage [1]

• In super-dense scenarios, in addition to general indoor (from 802.11n/ac channel model) or outdoor (from WINNER or ITU model), we need to consider the following environments as well

Slide 3 Minho Cheong (NEWRACOM)

AP

My STA(smart phone)

Mar. 2014

doc.: IEEE 11-14/0112r1

Submission

• Measurement schedule & Measurement spot– Seoul Express Bus Terminal (indoor) in Seoul in January 2014

• Equipment– AirMagent Wi-Fi Analyzer Pro, Mobile AP, Jperf 2.0.2 Server

• Measurement done on 2.4GHz (channel 9) by 802.11g– Measured DL PHY data rate from Laptop to mobile AP

– Measured & analyzed DL MAC packets from Laptop to mobile AP

Measurement Campaign

Mar. 2014

Slide 4 Minho Cheong (NEWRACOM)

Mobile AP

Jperf server (wired)Laptop

doc.: IEEE 11-14/0112r1

Submission

• 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

Measurement Campaign (2)

Mar. 2014

Slide 5 Minho Cheong (NEWRACOM)

doc.: IEEE 11-14/0112r1

Submission

• 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)

PHY Measurement results of DL traffic

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. 1496.18 1384.01 296.25

Mar. 2014

Slide 6 Minho Cheong (NEWRACOM)

Mobile AP

Jperf server (wired)Laptop

doc.: IEEE 11-14/0112r1

Submission

MAC Measurement results of DL traffic

Mar. 2014

Minho Cheong (NEWRACOM)

• 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 % 6 % 6 %

Slide 7

Retry rate 0.05 people/m2 0.25 people/m2 0.5 people/m2

Retry rate 11 % 12 % 24 %

doc.: IEEE 11-14/0112r1

Submission

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)

Mar. 2014

Slide 8 Minho Cheong (NEWRACOM)

doc.: IEEE 11-14/0112r1

Submission

References

• [1] 11-13-1113-00-0hew-channel-modeling-for-dense-Wi-Fi-environments

Mar. 2014

Slide 9 Minho Cheong (NEWRACOM)