Wireless Communication Testbed

Purdue University and the University of Michigan have been jointly developing a testbed with support from the Defense University Research Instrumentation Program (DURIP) that became available in 1995. This testbed is to be used to study wireless communication systems, particularly satellite links used in such systems. The planned operation of the communications testbed is from any terminal connected to the Internet to open, for example, two X-Windows. One window would control the transmitter at Purdue and the other would examine (at Purdue) how the signal looks when it is received via satellite at Michigan. This is possible because the display at Michigan is passed via the Internet back to Purdue to appear as the second X-Window on the local display. Not only can the display be returned to Purdue, but samples of the received signal can be loaded onto disk at Michigan and the file of samples can be sent by Internet back to Purdue for later off-line studies to determine how other forms of modulation and coding would have performed.
This now makes it possible, for example, when visiting a laboratory to demonstrate results with actual signals by simply logging on to a terminal running X-Windows that is connected to the Internet. The testbed focuses on the development of spread-spectrum communication systems for developing digital cellular and personal communication systems as well as satellite communications using devices that are developed as part of a solid state research program. Between the universities, information is being shared about setting up the equipment and the testbed to reduce the time burden on any one faculty member and to allow faculty to focus on basic research at the same time they communicate via papers and the testbed to industry and the military. The useful transmission of information that guides research into the universities from military and industrial partners promises to greatly improve programs at the schools.