Education is paramount
To plan, design, install, operate and maintain fiber-optic networks, managers and engineers involved in telecommunications, video communications and data communications must master the principles of lightwave, electronic and communication technologies, components and systems. Learning these principles while bombarded by a bewildering array of standards, architectures and products mandates a continuous educational process that encompasses a variety of instructional sources, such as publications, seminars, trade shows and courses, among others.
Ongoing training in fiber optics technology is necessary because this field is still a relatively new science that is, therefore, undergoing constant modification. Less than 20 years ago, in 1976, AT&T Bell Laboratories in Atlanta demonstrated an 11-kilometer telecommunications network using a 144-fiber cable. Each fiber could handle 672 telephone calls without repeaters. Technology growth, since then, has been rapid and innovative.
What makes fiber optics technology difficult to learn is that it is a hybrid field. That is, it incorporates other technologies. Although it originated in the optics field, fiber slowly evolved into a cost-effective transmission link by assimilating various aspects of electronics, communications, laser and copper technologies.
Not to worry. A major goal of every issue of Lightwave is educating its readers on fiber optics technology, applications and products. And this month`s special report presents technical articles that make up a primer of relevant fiber optics topics useful for novices and veterans alike.
For example, Dave Watson of Belden Wire & Cable Co. covers fiber-optic cables and accompanying system design rules. Fiber cable designers and planners must deliberate carefully, says Watson, so that currently installed cable plant can be upgraded quickly and conveniently.
One of the widely ignored specialties in the field of fiber optics is how to buy products. Eric Pearson of Pearson Technologies shares his many years of experience in choosing and purchasing optical components. He has assembled 16 proven rules that focus on a common theme: Buy only the product performance needed for the application.
To investigate light transmission through fiber-optic cables, Dan Beougher of Tektronix has formulated a half-dozen tests that yield complete characteristics.
A basic fiber-optic transmission link is rife with noise and distortion effects that torment designers. Hank Blauvelt and Larry Stark of Ortel explain the intricate workings of the required electro-optical components.
Lastly, Don Tolmie of the Los Alamos National Laboratory and Don Flanagan of the Hippi Networking Forum publicize the merits of the ANSI-approved high-performance parallel interface standard. Relatively unknown compared to the Fibre Channel and FDDI standards, Hippi outperforms both of them in delvering fiber-optic networking capabilities.
Compare apples to apples
To the Editor:
Lynn Haber`s article "AT&T advocates dual fiber modes" (see Lightwave, June 1995, page 1) missed the main point by failing to compare the cost and functionality of the two architectures. The statement "deployment of fiber-to-the-curb networks should cost approximately $800 to $1500 per home versus $150 per home for hybrid fiber/coaxial cable networks" makes an "apples and oranges" comparison.
Video-only hybrid fiber/coaxial-cable is relatively cheap, at approximately $200 per home passed, depending on demographics and population density. But the fiber-to-the-curb architecture should be compared with an integrated-voice-and-video HFC cable architecture, which costs significantly more than the video-only HFC. As vendors put together integrated HFC solutions, they are finding that adding voice over HFC to the existing video solution is expensive and somewhat difficult. As a result, the total cost of an integrated HFC solution is often only marginally lower, and sometimes even higher, than the cost of integrated fiber to the curb. And that appears to be a clear rationale for AT&T`s offering both architectures at comparable prices.
At a time when carriers are rethinking large deployment decisions in light of the small difference in costs between the two integrated architectures, providing the right information on costs is critical.
Deepak N. Swamy
Gemini Consulting C4 Lab