Network serves research and education projects

Communications News, April, 1986 by Alan Blatecky

Network Serves Research and Education Projects

The Microelectronics Center of North Carolina (MCNC), a nonprofit corporation located in Research Triangle Park, was established as a unique national resource for integrated microelectronics research and development. It serves as a neutral education and research center where all parties addressing the future of microelectronics can work together to meet the technical challenges that lie between basic research and manufacturing reality.

The center offers industry participation in all phases of advanced integrated-circuit manufacturing technology, including the basic and applied research performed at its Central Laboratory and six participating institutions: Duke University, North Carolina A&T State University (NCA&T), North Carolina State University (NCSU), University of North Carolina at Chapel Hill (UNC-CH), University of North Carolina at Charlotte (UNC-C), and the Research Triangle Institute (RTI).

MCNC provides an industrial-type research center for use by the university community and industry, coordinates a variety of university support programs, and conducts a coherent integrated program of research in microelectronics. The center supports interdisciplinary research and education and structures joint university-industry projects. A 10,000-square-foot ultraclean fabrication facility is being developed to process and fabricate submicron microelectronics chips for utilization in advanced manufacturing research and testing.

Objective: National Leadership

The center's primary objective is to develop national leadership in the area of high technology and microelectronics. Its working relationships bridge the gap between the industrial production environment and basic research being conducted by the university community. Whereas ordinary university centers do basic and applied research and industry is concerned with design and manufacturing aspects of production, MCNC, along with its industrial affiliates, fills this gap between research and production. Its program speeds the transfer of information and technology from the research community to high-technology industry.

To permit timely participation in research and education projects throughout the consortium, the center has installed an extensive communication network that provides transmission services for video, audio and data traffic. The MCNC communications system interconnects the six participating institutions with the Central Laboratory so that participants can interact through videoconferences, teleclasses and data exchange.

The primary functions of the system are to provide videoconferencing, teleclasses, voice interaction and digital communications throughout the MCNC community. The network has been designed to provide real-time, interactive capabilities. The network extends from NCSU at Raleigh westward to UNC at Charlotte, a distance of 152 miles. The network also interconnects Duke in Durham, UNC at Chapel Hill, NCA&T in Greensboro and RTI in Research Triangle Park.

In addition to the existing network, a project to extend the network to include UNC Asheville, Winston-Salem State University, Bowman Gray School of Medicine and the Center for Communications Signal Processing at NCSU is under way, with projected completion by the summer of 1987.

The network provides extensive video and data capabilities. Two duplex analog television channels are shared among all the institutions. The digital channel of 16 Tl channels provides substantial capabilities for computer networking, data transmission and research. The digital bandwidth has been allocated among many services, including Tl compressed video, and these channels will enable the network to provide more video services beyond that of the two analog channels.

The MCNC communications system consists primarily of microwave hops between the participating institutions and the Central Laboratory. Harris (Farinon Division) DM2-16-25 digital microwave radios are used for the digital transmission path. The vendor's M1-2 multiplexers break out the 25-Mb/s data path into 16 individual Tl (or four T2) circuits, and its broadcast video transmitters provide the video channels between the participating institutions and the laboratory.

The video is transmitted via narrow-band FM (10-MHz bandwidth) in the 6-GHz OFS (operational-fixed service) band. The data is transmitted via 2-GHz OFS frequencies using 10 MHz of bandwidth. Network specifications are based on a 54-dB signal-to-noise ratio for the video transmissions from end-to-end (RS 250B), and a 99.99-percent reliability. The digital transmission of 25 Mb/s is standby-protected and was designed to provide a maximum bit-error rate of 10(-6) from end-to-end. Actual testing has indicated a performance in excess of 10(-10). The RTI-MCNC microwave link is a 23-GHz M/A-Com system that consists of a full-duplex analog video channel and a T2 (four Tls) digital microwave channel.

While the backbone network utilizes microwave technology, the network uses fiber-optic links to interconnect the laboratory facility to the primary microwave tower in the research park. The interconnect is a Siecor-FiberLAN mono-mode 28-fiber optic cable and associated fiber-optic drivers and receivers. Each analog video signal uses a separate fiber for transmit and another for receive. Since nine video signals come into the laboratory (two from each of the four primary microwave hops and one for the RTI microwave link) and go back out, 18 fibers are used for the video interconnect alone. The digital circuits are multiplexed into a 45-Mb/s signal and transmitted over a pair of fibers.