By Patrick McLaughlin
The Fiber Optic Association (FOA) recently published two textbooks for use as reference guides to fiber optics and textbooks for training and certification. The books cover fiber-optic network design and outside-plant construction.
The FOA Reference Guide to Fiber Optic Network Design was authored by FOA president Jim Hayes. It focuses on the concepts of designing a fiber-optic network and how the entire process must be planned from idea through installation, operation and documentation. The FOA says the book is aimed at network designers, contractors, supervisors as well as management personnel responsible for communications and information technology (IT) departments, construction and facilities management. “Anyone whose responsibilities include communications systems will benefit from the information in this book,” the FOA said. “It is also the textbook used for the FOA CFOS/D Fiber Optic Design Certification.”
The FOA Outside Plant Fiber Optic Construction Guide was authored by Joe Botha of Triple Play Fibre Optic Solutions of South Africa. It is a detailed guide to the construction involved in the installation of OSP fiber-optic cable plants. Included are aerial and underground construction techniques, safety procedures, permitting processes and many other details involved in the construction of fiber-optic cable plants. Botha is a Fiber Optic Association Master Instructor.
Within the Network Design Guide, Hayes explains, “The Internet has always been based on a fiber-optic backbone. It started as part of the telephone network when it was primarily voice, and data traffic was mixed into the total traffic. But data has become the largest communications network as data traffic has outgrown voice traffic. The Internet now transmits user communications, e.g. requesting and downloading web pages or email, peer-to-peer transmissions, streaming video and massive data transfers between data centers. Large Internet providers are moving toward dedicated Internet networks that do not have the high overhead of telco networks.”
On CATV networks, he writes, “Most CATV systems are using fiber backbones. CATV companies use fiber because it gives them greater reliability and the opportunity to offer new services, like phone service and Internet connections. CATV used to have a terrible reputation for reliability, not really with service but with network topology. CATV uses very high frequency analog signals, up to 1 GHz, which has high attenuation over coax cable. For a city-wide system, CATV needed many amplifiers (repeaters) to reach the users at the end of the system; fifteen or more were common. Amplifiers failed often, meaning that subscriber downstream of the failed amp lost signal. Finding and fixing failed amps was difficult and time-consuming, causing subscriber complaints.
“The development of highly linear distributed feedback (DFB) lasers allowed CATV systems to be converted to analog optical systems. CATV companies ‘overbuild’ with fiber. They connect their headends with fiber and then take fiber into the neighborhood. They lash the fiber cable onto the aerial ‘hardline’ coax used for the rest of the network, or pull it in the same conduit underground. The fiber allows them to break their network into smaller service areas, typically fewer than four amplifiers deep, that prevent large numbers of customers from being affected in an outage-making their network more reliable and easier to troubleshoot, providing better service and customer relations.
“The fiber also gives CATV operators a return path, which they use for Internet and telephone connections, increasing their revenue potential. Most current CATV systems still use AM (analog) systems, which simply convert the electrical TV signals into optical signals. Look for them to convert to more digital transmission in the future. CATV is even developing its own version of fiber-to-the-home over a PON [passive optical network] called RF over glass (RFOG). This uses an interface at the home that is like a cable modem but with an optical input that uses the same analog radio frequency (RF) signals that are used throughout the HFC network.”
Because there is such a large variety of OSP installation, it is difficult to generalize about what is involved in an OSP design, Hayes points out. “OSP installations of fiber-optic cables can be much more diverse than premises installations,” he explains. “OSP installs may include installing aerial cable, direct-buried cable, underground cable in conduit or installing conduit or innerduct and then pulling cable, or placing cable underwater. A single link may include several types of installation, for example aerial in one section, pulling in conduit on a bridge crossing and burying the rest of the cable.
“Cables may end when pulled into buildings or terminated at the top of poles where surveillance cameras or wireless access points are located. Splices where cables are concatenated can be placed in pedestals, buried underground or hung in aerial splice closures.”
In the preface to the Outside Plant Fiber Optics Construction Guide, the FOA said, “This textbook is a guide to outside plant fiber-optic construction-basically the process of installing the fiber-optic cable plant including the work necessary before the fiber-optic techs begin splicing, terminating and testing the cable plant. This book was written by Joe Botha as a textbook for classes he teaches on construction. Joe created the course to fill a need for training OSP construction crews. The book covers topics which are rare in textbooks-practical solutions to designing and installing the fiber-optic cable plant. It is an extremely valuable reference book for all owners, designers, supervisors and installers of fiber-optic OSP networks.” The 64-page book covers more than 100 topics related to OSP construction.
Both books are available direct from the FOA eStore or Amazon, as well as local booksellers and other distributors.
Patrick McLaughlin is our chief editor.