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GNU Radio
GNU Radio is a free software development toolkit that "provides the signal processing runtime and processing blocks to implement software radios using readily-available, low-cost external RF hardware and commodity processors. It is widely used in hobbyist, academic and commercial environments to support wireless communications research as well as to implement real-world radio systems." Here is a list of my docs about GNU Radio.
IEC61850 GOOSE development kit
IEC61580 is a recent and developing communication protocol for power substations. GOOSE is a time-critical message type in IEC61850. For research purpose, we developed a GOOSE toolkit in Linux, including a loadable kernel module (based on version 2.6.32) and user-space libraries.
A simple and raw kit is avaliable at
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Misbehavor in a WiFi network
Misbehavior in WiFi networks is a recent topic in wireless security. By performing misbehavior, a selfish user can achieve unfair resource access among all WiFi users. It also is related to our backoff-misbehavior paper published in INFOCOM 2010.
Why? In a nutshell, WiFi is based on CSMA/CA. which requires users to considerately wait a random time for others before they transmit their own data. We surely can reduce the random wait time to gain unfair access to the wireless channel. The idea is: everyone is considerate except for me..
How? We need Linux and the Madwifi driver. Madwifi features a command line to modify parameters of a network interface card:
- iwpriv dev param traffic mode value
dev is usually ath0, ath1, wlan0, wlan1, depedent on your computer.
param is what we need to modify, including cwmin and cwmax
traffic includes four types from 0 to 3.
mode indicates AP (0) or station (1).
value is the intended value we want. Default values for cwmin and cwmax are: 4/5 and 10, respectively.
Now, we can use (with sudo), for example,
- iwpriv ath0 cwmax 0 1 1
- iwpriv ath0 cwmin 0 1 1
to achieve the most selfish backoff-misbehavior in WiFi networks.
We here give an example of parameter manipulation in WiFi cards. We neither encourage nor support such misbehavior in WiFi networks.