The effect of using directional antennas on adjacent channel interference in 802.11a: Modeling and experience with an outdoors testbed

We present an outdoors 802.11a testbed based on off-the-shelf components that we used for multi-radio node experimentation. This is the first such testbed, to our knowledge, equipped with directional antennas. With it we conducted a thorough and systematic set of measurements, in medium range outdoors links, to examine how the physical separation of the antennas, the output power of the interfaces, and the channel separation of the links affect throughput. For the setup of the testbed and to estimate the induced ACI we utilized a theoretical model, already verified on an in-lab wireless testbed emulator [Angelakis, 2008]. We discuss how the model needs to adapt and propose to create a tool for the design of large scale multi-radio wireless networks.