1. Measurements of 802.11 behavior in different environments
January 2013
doc.: IEEE /0153r0
July 2016
Measurements of behavior in different environments
Authors:
Date:
Jim Lansford (Qualcomm/CU-Boulder)
Clint Chaplin, Chair (Samsung)

2. January 2013
doc.: IEEE /0153r0
July 2016
Abstract
As a class project, students made measurements of channel occupancy of WLAN traffic in different environments to assess how much time is spent in each of the data rates and overall protocol efficiency.
Jim Lansford (Qualcomm/CU-Boulder)
Clint Chaplin, Chair (Samsung)

3. July 2016
Problem Statement
Use packet capture and analysis tools to analyze the temporal occupancy, packet type distribution, and data rate distribution of deployed systems in the following environments:
High density, unmanaged public retail networks
Managed university network (campus-wide ESS)
Residential unmanaged networks
Jim Lansford (Qualcomm/CU-Boulder)

4. July 2016
Methodology
Most students used Microsoft Network Monitor to capture packets
Has a “monitor mode” to capture packets by scanning across channels (unassociated)
Some students used OmniPeek if they had access
Save as a .cap file so Wireshark can analyze
Students used Excel to create charts
Some wrote custom scripts to analyze packets
Summarize results in reports
Many students submitted captured packet traffic (.cap files) but that was not required
Most students only examined 2.4GHz networks, so that is all that will be summarized here
Jim Lansford (Qualcomm/CU-Boulder)

5. July 2016
Data Capture #1
Microsoft Network Monitor (free) can be used to capture packets in any channel in unassociated mode
- OmniPeek has the same capability, but isn’t free
Jim Lansford (Qualcomm/CU-Boulder)

6. Data capture #2 Wireshark used to sort and classify packet traffic
July 2016
Data capture #2
Wireshark used to sort and classify packet traffic
Jim Lansford (Qualcomm/CU-Boulder)

7. Locations for Measurements
July 2016
Locations for Measurements
Pearl Street Mall (dense retail shops)
Unmanaged networks
University of Colorado Campus
Managed network – ESS
Residential environment
Dorm, apartment, house
Pearl Street Mall
Engineering - University of Colorado at Boulder
Jim Lansford (Qualcomm/CU-Boulder)

8. Results #1: Pearl Street (1/3)
July 2016
Results #1: Pearl Street (1/3)
Jim Lansford (Qualcomm/CU-Boulder)

9. Results #1: Pearl Street (2/3)
July 2016
Results #1: Pearl Street (2/3)
Jim Lansford (Qualcomm/CU-Boulder)

10. Results #1: Pearl Street (3/3)
July 2016
Results #1: Pearl Street (3/3)
WLAN packets were on the air about 3.9 seconds out of a 10 second period
Jim Lansford (Qualcomm/CU-Boulder)

11. Results #2: CU-Boulder (1/3)
July 2016
Results #2: CU-Boulder (1/3)
Jim Lansford (Qualcomm/CU-Boulder)

12. Results #2: CU-Boulder (2/3)
July 2016
Results #2: CU-Boulder (2/3)
Jim Lansford (Qualcomm/CU-Boulder)

13. Results #2: CU-Boulder (3/3)
July 2016
Results #2: CU-Boulder (3/3)
WLAN packets were on the air about 0.8 seconds out of a 10 second period
Jim Lansford (Qualcomm/CU-Boulder)

14. Results #3: Residential (1/4)
July 2016
Results #3: Residential (1/4)
Jim Lansford (Qualcomm/CU-Boulder)

15. Results #3: Residential (2/4)
July 2016
Results #3: Residential (2/4)
Jim Lansford (Qualcomm/CU-Boulder)

16. Results #3: Residential (3/4)
July 2016
Results #3: Residential (3/4)
WLAN packets were on the air about 3.1 seconds out of a 10 second period
Jim Lansford (Qualcomm/CU-Boulder)

17. Results #3: Residential (4/4)
July 2016
Results #3: Residential (4/4)
As expected, Channels 1, 6 and 11 are most popular in 2.4GHz, and 1Mbps packets are most common
Jim Lansford (Qualcomm/CU-Boulder)

18. Summary (2.4GHz) 1Mbps traffic predominates
July 2016
Summary
(2.4GHz) 1Mbps traffic predominates
Beacons
Probe request/response - In congested environment, many more probe responses than probe requests
RTS/CTS
Significant amount of dead time even in congested environments
Roughly 40% temporal occupancy
One student examined retries and found about 35% of packets needed retries in the mall environment
Over 75% of packets were management frames in congested environments
Impact of ax?
All papers are available as well as much of the raw data
Jim Lansford (Qualcomm/CU-Boulder)