FOA Guide 

Introduction To Broadband

In less than half a century, fiber optics has revolutionized communications and in many ways, society in general. Broadband, what many today call high speed Internet access, has become a necessity for everyone, not a luxury. The technology that makes broadband possible is fiber optics, connecting the continents, cities, and just about everybody. Even fiber to the home (FTTH) brings broadband to hundreds of millions worldwide.

How did we get from an era when communications was just making a telephone call or sending a telegram to today’s world where every piece of information – and misinformation – is available at the click of a mouse or touch on a screen? How did we get from a time when a phone was connected on copper wires to being able to connect to fiber optics at home or practically anywhere on a handheld wireless device?

How does all this broadband work? Without fiber optics it would not work. These web pages will explain not only how fiber broadband works, but how it was developed. It is perhaps as much about history as technology.

What Is Broadband?

Ever wonder about the origin of "broadband"? If you look at some of the millions of links you get from an Internet search for “broadband,” almost every link has a different definition according to their viewpoint. Here’s the “first-hand” story from some of the people who participated in the beginnings of broadband. 

In February 1997 in the suburbs of Boston, Massachusetts, the first consumers were connected to the Internet with what we call "broadband" today. 

Up to that point, most users connected to the Internet with "dial-up" modems on a POTS (plain old telephone service) copper line. Dial-up connection speeds at the time were mainly 14.4 kilobits per second or 56 kilobits per second. Yes, kilobits per second - thousands of bits per second. The only alternatives for digital phone connections was T1 service at 1.544 megabits/second  and thousands of dollars per month connection fees. ISDN (Integrated Services Digital Network) over copper phone wires had been announced but was rarely available and faded quickly.

The innovation that introduced "broadband" Internet access to the consumer was the Cable Modem, developed in the Boston, Massachusetts area by Rouzbeh Yassini at Applitek.  Yassini turned Applitek into LanCity to manufacture the cable modem for CATV companies.

The original Applitek design was a networking system using coax cable and FM (frequency modulation), a technique then called "broadband". Yassini realized the commonality of design with CATV systems and developed a system to put data on spare channels of a CATV system and the cable modem as created. It became the industry standard, DOCSIS, Data Over Cable Service Interface Specification.

The actual LanCity hardware is shown in the photo below. The engineer is holding the first LanCity cable modem installed in homes in 1997. The large PC case is one of the original prototypes. The video gives an insider's story of the development.

Lancity cable modem box

Gene O'Neill tells the story of working with Lancity to develop the cable modem. The big box was the prototype tested on a school I-Net (institutional network) coax cable TV system. The smaller gray box he is holding is what was installed in the first homes by Continental Cablevision in February 1997. Watch the Video on YouTube.

The T1 line from the phone company and most other networks like Ethernet were AM (amplitude modulation) systems commonly called "baseband" systems. When a broadband network like CATV with cable modems became the source of high data rate Internet access, broadband became synonymous with high bandwidth. Today broadband refers to any high bandwidth network. Fiber broadband is probably redundant since no high bandwidth network runs without fiber optics.

CATV companies were already making another revolutionary change. The scientists at Bell Labs developed a new type of laser, the distributed feedback (DFB) laser that was capable of reproducing CATV signals optically. CATV companies began replacing their coax backbones with fiber optics in what they called a hybrid fiber-coax (HFC) network. The HFC network was more reliable (a problem of coax CATV networks) and allowed CATV networks to cover larger areas.

The combination of the large numbers of homes already subscribers to CATV and the technologies of HFC networks and cable modems made broadband a reality to many subscribers very quickly. This allowed CATV companies to dominate the Internet provider market for decades.

The telcos tried to match cable modem speeds over their twisted pair wires but with little success. The development of digital subscriber line (DSL) lasted through more than 20 generations of standards and still has advocates today, although most major telcos have abandoned it in favor of fiber to the home (FTTH.) DSL was never going to be able to keep up because of the physics of transmitting electrical signals over the telco twisted pair wires.

Fiber to the home (FTTH) became economically feasible in the early 2000s with the development of the passive optical network (PON) using inexpensive  optical splitters to replace expensive electronic switches. Today, hundreds of millions of subscribers worldwide are connected on FTTH.


Here are two techs installing an early FTTH system on a home.

Fiber to the home is considered the ultimate solution to provide broadband for today and the foreseeable future, but the CATV companies have not been standing still. From the original cable modem speeds of 4 Mb/s, they have developed new cable modem technology that can now do gigabit speeds for downloads but are more limited in upload speeds. Most CATV companies have experimented with and are prepared to move to FTTH when necessary.

Today, the term “broadband” has become synonymous with high-speed Internet, but few know that it comes from the technology behind our first high-speed, always-on Internet.

Fiber Broadband Jargon

The key to understanding any technology is understanding the language of the technology – the jargon. We’ve started this book with an overview of fiber jargon to introduce you to the language of fiber broadband  and help you understand what you will be reading about in the book.

What is Broadband?
Broadband today means networks that offer high-speed always-on Internet access, provided by fiber to the home (FTTH), CATV cable modems or wireless networks like 5G. The term broadband comes from the early networks that used coax cable because of its higher bandwidth capability and sent signals on frequency channels. Over time, it came to mean any high-speed always-on Internet network.

Fiber Broadband means broadband delivered on fiber optics. Fiber broadband offers much more bandwidth for broadband that other options. But in fact, all communications are based on fiber optics; even the wireless options use fiber optics for all connections except the final short link to the user’s smartphone, tablet or other wireless device.

What Is A Network?
A network is a communications system shared among many users. The phone system and the telegraph system before that were networks. A CATV system in a network. The Internet developed from the earliest attempts to connect computers at many locations.

What Is The Internet?
That’s not easy to define in a short paragraph, but the Internet is the worldwide communications system used today to allow voice, data and video communications.

What Is Fiber Optics?
Fiber optic communications means sending signals from one location to another in the form of modulated light guided through hair-thin fibers of glass or plastic. These signals can be either analog or digital and transmit voice, data or video. Fiber can transport more information longer distances in less time than any copper wire or wireless method. It’s powerful and very fast - offering more bandwidth and distance capability than any other form of communication! That also makes it the most economical means of communication.

fiber vs copper    

This photo from the late 1970s shows copper and fiber optic cables of equal capacity at that time. It illustrates the advantage of fiber so well. The bandwidth and distance capability of fiber means that fewer cables, fewer repeaters, less power and less maintenance are needed. Even when fiber was first being deployed, the cost of communications on fiber optics was only a few percent of the cost on copper wires or wireless.

bandwidth of broadband technologies

This graph comparing the relative bandwidth available in various communications media shows how fiber provides much higher bandwidth than any other option. The bandwidth and distance capabilities of fiber optics makes it the medium of choice for every communications network, from connecting homes to spanning continents.

Earth with fiber optic cables

For more information on fiber optics in general, go to the FOA Guide section on Basic Fiber Optics.

More FOA Resources On Broadband

FOA Guide To Fiber Broadband

FOA Guide To Fiber BroadbandHow does broadband work? Without fiber optics it would not work; even wireless has a fiber backbone. This book is not the typical FOA technical textbook - it is written for anyone who wants to understand fiber broadband or fiber optics or the Internet. It's also aimed at STEM teachers who want to include communications technology in their classes. This book will try to explain not only how fiber broadband works, but how it was developed. It is intended to be an introduction to communications technology appropriate for a communications course at almost any level (junior high, high school or college,) for managers involved with broadband projects, or for anyone who just wonders how all this stuff works.

The Fiber Optic Association Guide To Fiber Broadband   Paperback ($12.95) and Kindle ($9.95) versions available from Amazon or most booksellers. Kindle version is in color!

The Fiber Optic Association Fiber To The Home Handbook

FOA FTTH Handbook
For Planners, Managers, Designers, Installers And Operators Of FTTH - Fiber To The Home - Networks
This book is a compilation of all the FTTH materials from the FOA Guide and FTTH CFOS/H certification curriculum with additional materials covering project design and management. The FOA materials come from almost two decades of experience with FTTH including developing training curriculum for training techs for the earliest commercial installations of FTTH and consulting with many diverse FTTH projects.

This handbook is written to provide the technical information that can help a service provider understand how to start a FTTH project or a local organization decide if they want to create a do-it-yourself FTTH project run by their local government, electrical coop or a public-private partnership.

The Fiber Optic Association Fiber To The Home Handbook
Available in paperback or as an eBook on the Amazon Kindle  Available direct from, local booksellers and other distributors.

Technical Information on FTTX  From The FOA Online Guide
FTTH Introduction  

Training & Certification
Fiber U Online FTTx Self Study Program (free)

Internet Resources For Broadband  

Table of Contents: The FOA Reference Guide To Fiber Optics


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