Wireless Trace Analysis Suyong Lee and Renata Aryanti Advisor: Prof. Suman Banerjee With assistance of : Vladimir Brik and Michael Blodget Fall 2007

What we are doing …  Analyzing the wireless traffic traces in Helen C. White College Library building, located in 600 N. Park St, Madison, WI. 1. Contention 2. APs’ Popularity and Traffic Distribution Among APs 3. Mobility Pattern 3. Users’ Connection Trend (length and number of APs the user usually connect in a day) 4. Data Rate Distribution 5. Download VS Upload Stream 6. Traffic Distribution Among APs 7. Control Packet Distribution

HCW AP location

Network Usage Of all the wireless traces collected in HCW College Library: –86% is using UW-Net- Helen-C-White network –6% is using other UW network, such as: Memorial Union, Memorial Library, Science Hall, or Water Science network. –8% are using foreign network.

Contention  We will show the number of nodes connected on each AP over time. Each color on the diagram represent different APs.  The data is taken from the AP logs on May 15 th – 17 th, This is the final exam week of Spring 2007 term.  The busiest time (when many nodes are connected) for 1 st – 3 rd floor is shown to be evening, around 7pm – 1am.

Contention – 1 st floor On May 17 th, the number of nodes connected to the 1 st floor AP did not go up in the evening (as it did in May 15 th and May 16 th ), as people tend to move up to the 2 nd and 3 rd floor (there are larger space to study in 2 nd and 3 rd floor).

Contention – 2 nd floor

Contention – 3 rd floor

Contention – 4 th floor The busiest time in 4 th floor tends to be in the afternoon, between 9am – 3pm. The 4 th floor is used as offices, so most nodes are connected during business hour.

AP Popularity -- Association, Disassociation, MaxRetries, and Roaming May 15 th, 2007 In the first and second floor, the users are not distributed very well among AP. In the third to fifth floor, the distribution of the users among AP are better. 1 st Floor: 1200 is the least popular AP 2 nd Floor: 2191a is extremely popular and 2257 is the least popular 6 th and 7 th floor: only 1 AP is dominant on each floor.

Association, Disassociation, MaxRetries, and Roaming (Continue) May 16 th, 2007 –The trend is similar to May 15 th. –In the first floor, the users are not distributed very well among AP, 1200 is the least popular AP. –In the second floor, 2191a is the most popular AP and 2257 is the least popular. –In the third floor, the distribution of the users among AP are better. –3191d and 3205a are the most popular. - In the 4 th floor, 4191a is the most popular - In the 5 th the difference among APs are not very significant. - In the 6 th – 7 th floor, only 1 AP is dominant in each floor.

Association, Disassociation, MaxRetries, and Roaming (Continue) May 17 th, 2007 We have slightly different trend of AP popularity on the 1 st – 3 rd floor. 1 st floor : is no longer the least popular is the most popular 2 nd floor: is the most popular, instead of 2191a as in the previous 2 days. 3 rd floor: 3205 and 3215 are the most popular 4 th – 7 th floor: only 1 AP is dominant on each floor.

Traffic Distribution between APs  The traffic go pass each APs

Mobility  Analyze the prevalence of each user.  Prevalence : the fraction of length each user connected on each AP compared to the whole connection time to the whole network.

Prevalence  May 15 th, 2007  40.2 % users are staying in 1 location.  36% users are moving around but are dominant in 1 location (0.8 1) May 15 th, 2007

Prevalence May 16 th, 2007  May 16 th, 2007  50 % users are staying in 1 location.  26% users are moving around but are dominant in 1 location

Prevalence May 17 th, 2007  May 17 th, 2007  61 % users are staying in 1 location.  16 % users are moving around but are dominant in 1 location

Users’ Connection Pattern  The data is taken from the AP logs May 15 th – may 17 th  We are looking at these trends: How long each user connected to the network every day. How many APs the users usually connected to in a day.

Length of Connected for users  May 15 th – May 17 th 2007  ~ 40% users were connected less than 1 hr.  20%- 30% users are connected between 1-3 hrs a day.

Number of APs users get connected in a day  May 15 th – May 17 th  ~ 70% of users are connected to 1–2 APs everyday.  ~ 25% of users are connected to 3 APs – 5 APs everyday.  Only about 5% of users are connected to more than 6 APs.

Data Rate Distribution  Only a few packets are sent using higher data rate, such as 54Mbps and 48Mbps.  The dominant data rate is 11Mbps.  The reason is that DoIT tries to force the data rate to be 11Mbps when there are a lot of users connected at the same time. This way they can share the bandwidth even though there are many users connected.

Download VS Upload Stream  Analyze the download VS upload stream for each AP.

Control Packet Traffic Distribution  CTS is dominating the control packet sent through the network.  CTS >> RTS

- END - Thank you !!