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Experiments are being conducted in the newly constructed ground plane laboratory. As seen at left, Professor Butler is assisting a graduate research fellow in inserting a probe which is used to measure the current on an antenna. Notice the electromagnetic absorber on the surrounding walls. |
The newly completed Fluor Daniel Engineering Innovation Building houses wireless communication systems and networks at Clemson University. Wireless communications research is conducted in four laboratories: the Holcombe Laboratory for Digital Communications, the Barnes Telecommunications Laboratory, and the ITT Laboratory for Spread Spectrum Communications. In addition, facilities are shared with other research groups in several other laboratories.
The Holcombe Laboratory contains a high-speed Sun SPARC computational server with 20 processors that is used for research on mobile spread-spectrum communication systems and networks. The workstations are equipped with communication system simulation packages that permit computer simulation of key elements of radio communication systems and networks. One software package is the Signal Processing Worksystem, a high-end simulation environment that enables the simulation of wireless communication links over a variety of channels in conjunction with a highly detailed specification of the transmitter and receiver hardware. Extensive use is made of OPNET for simulation of mobile, distributed, wireless communication networks. New simulations are being developed for direct-sequence spread spectrum networks with distributed protocols. The workstations are also equipped with C and FORTRAN compilers that are used for more specialized analysis and simulations of wireless communication subsystems and systems.
The computer system employed by the Wireless Communications Program for the most computation-intensive research consists of twelve DEC Alpha processors operating at 667 MHz. In addition, twelve older DEC Alpha processors are part of the system. The processors employ the Tru64 operating system (a variant of Unix) and include DEC's Load Sharing Facility (LSF), DEC FORTRAN, and Parallel Virtual Machine (PVM). DEC LSF allows large jobs to be load balanced across the cluster of processors, while PVM provides an easy-to-use message passing facility for writing coarse-grain parallel programs that utilize all of the processors.
The processors are connected via a DEC Gigaswitch crossbar switch that allows transfers between any two processors at speeds up to 100 Mbits/sec. This allows sufficient communication throughput among the processors in the current configuration to support efficient parallel processing. The Gigaswitch also allows sufficient throughput to the campus network backbone for transfer of data to remote workstations for programming, visualization, and data analysis.
This facility is used for both sequential and parallel computational electromagnetics programs, simulation of wireless communication links and networks, parallel satellite data analysis programs, and experimental systems software which is designed to simplify the task of scientific and engineering programming on a distributed cluster of computers. Access to the facility is limited to the faculty and students of the Wireless Communication Program and two other faculty members and their students.
The Sun workstations and Alpha processors are complemented by a variety of Macintosh and Pentium-based personal computers that are housed in the ITT Laboratory and the Computational Electromagnetics Laboratory. These computers are equipped with FORTRAN software and also serve as additional terminals for the high-speed processors.
