Rate Adaptation Classifier (RAC)

This is the Rate Adaptation Classifier (RAC) which passively listens to data traffic between wireless stations. Based on the observed traffic, RAC performs logging and statistics. The final output of the application can be used to classify the rate adaptation algorithm used by the observed wireless device. RAC can be used on any platform which exports the correct headers to user-space through the PCAP framework. RAC has the ability to listen and analyse any IEEE 802.11b/g wireless network and contains code to perform basic statistics on IEEE 802.11n.

RAC captures and logs the important pieces of observed data traffic and is not affected by the encryption used by the wireless network. RAC is only interested in the Physical (PHY) and some Link-Layer information exported by the monitor interface.

Enter the src directory and type:

For a debug build, type:

This will build the application without the ui.

USAGE: ./rac

NB: The application need to be ran as root.

On exit, the application writes the following files to /tmp/

• losses.dat: Log of estimated lost frames. This is losses to the capture process, not necessarily losses between the station and the access point. The file contains two columns, the first is unix time, the second is the estimated number of lost frames.
• rate_changes.dat: This file contains the rate changes seen during the capture process. First column is unix time, second is the new bit-rate and the third is the sequence number on the first frame seen with this bit-rate.
• rates80211bg.dat: This file contains the number of frames seen for the different 802.11 legacy bit-rates. First column is the bit-rate, second is the number of frames and the last is the frame count in percent to the total of frames. rates80211n.dat: This file contains the distribution of IEEE 802.11n frames seen. The file has five columns. The first is the MCS index. The second and third column is the number of captured frames for the long Guard Interval (GI) frames in 20MHz and 40MHz channel widths. Column four and five represents the number of frames received for the short GI, 20MHz and 40MHz channel widths.
• retries.dat: This file contains captures retransmission rates. The file contains the time, the original bit-rate and the bit-rate of the retransmitted frames. First column is unix time, second is the total number of retransmissions, third column is the original frames bit-rate and the rest of the column is the bit-rate of every retransmission. If a frame has been retransmitted four times, there will be four columns following the three first.
• samples.dat: This file contains captured samples. The file structure is unix time in the first column and the bit-rate of the captured sample in the second.
• statistics.dat: This file is a dump of the statistics kept by RAC. The statistics kept are: * Number of captured frames * Estimated lost frames * Captured retransmits * Loss ratio * Total number of rate changes * How many rate changes which change more than one rate step * Maximum rate changes per second * Minimum time between rate changes * Minimum number of frames between rate changes * Total number of samples * Sampling ratio * Minimum number of frames between samples * Number of RTS frames * Number of CTS frames * Maximum number of retransmissions for a single frame