The National Science Foundation and several major companies plan to announce today that important sections of a coast-to-coast network used to transmit computer research data will be upgraded so that information can travel 28 times faster than now possible, according to those familiar with the plan. It would be the first public research network to achieve such speeds.

MCI Communications Corp. will provide new cable links between eight major research centers on the network later this year to allow transmission of 45 million bits of information per second, the equivalent of 1,400 single-spaced typed pages of text. International Business Machines Corp. will provide certain equipment and software.

The program would lead toward a separate project that NSF announced last week to begin research into the feasibility of an "information highway" capable of rushing data at 1 billion or more bits per second. In essence, what the developers are doing is trying to widen the pipe through which this information travels.

"This is one more step toward achieving that ultimate objective," said Douglas E. Van Houweling, chairman of Merit Computer Network in Ann Arbor, Mich., which runs the existing system. Many analysts believe that building an ultra-high speed transmission network of this sort is a key to the future competitiveness of the U.S. economy.

The existing system, known as NSFNET, links 1,500 university, industry and government labs, allowing researchers to transfer data between computers at the comparatively slow speed of about 1.5 million bits of information per second. This means that researchers must wait hours or even days as the system transmits to them research results that may number in the billions of bits. Lawrence Bouman, a senior vice president at MCI, said the new system would speed up their work by allowing them to transfer data more quickly.

Research centers near the eight sites will have the option of upgrading their links to the sites to accommodate the new speed. Even if they don't, however, benefits will accrue, said Van Houweling, because lines coming out of high-traffic sites such as the Massachusetts Institute of Technology, which serve many sites simultaneously, will not become clogged as quickly.