The Light Fantastic: The Advantages of Fiber

This primer covers the key economic and technical issues surrounding fiber to the home. It explains why we believe you will agree that:

• FTTH - that is, Fiber to the Home - is the only technology that will deliver enough bandwidth, reliably and at a low enough cost, to meet the consumer demands of the next decade.
• FTTH is affordable now, which is why hundreds of companies using hundreds of different business cases worldwide are racing to install it in thousands of locations.
• FTTH is also the only technology that will meet the needs of the foreseeable future, when 3D, "holographic" high-definition television and games (products already in use in industry, and on the drawing boards at big consumer electronics firms) will be in everyday use. Think 20 to 30 Gigabits per second in a decade.
• FTTH will enable products that we have yet to conceive of, but that we are certain will become necessities for living well and working well in the decades ahead. Look what just the past few years has brought: Mobile video, iPods, HDTV, telemedicine, remote pet monitoring... and thousands of other products.

The key concept is this: Fiber optic cable carries information by carrying pulses of light.
The pulses are turned on and off very, very fast. Multiple streams of information can be carried on the same fiber at the same time by using multiple wavelengths - colors - of light.

The pulses of light are created by lasers. The equipment to do that keeps getting faster, so the same old fiber can be used to carry ever more information. New equipment is just slipped in.

The ability to carry information is called bandwidth. Lots of bandwidth allows lots of information to be carried. Three of the biggest advantages of fiber are:

1. Signals travel a long distance inside fiber cable without degradation - 20 km (12 miles) or more under some circumstances. The closer fiber gets to a building, the faster the service that is available to the building's residents and businesses. Service providers have been bringing fiber closer and closer for years, and now they are bringing it inside end users' buildings.

2. Fiber cable is thin. It can, in fact, be made thinner than a human hair. It can be carried on a thin ribbon, or inside a "microduct" of hollow plastic only an eighth of an inch wide. One typical fiber cable configuration with about 200 superthin strands is about the thickness of a standard coax cable. That fiber cable could theoretically carry enough bandwidth to handle all the information being sent on Earth at any one time today. The bottom line: Fiber can be "hidden" easily on the surfaces of walls in old construction.

3. Once installed, fiber is upgraded by changing the electronics that creates the light pulses, and not by replacing the cable itself. The fiber is amazingly reliable. Nothing hurts it except a physical cut, or the destruction of the building it is in. Passive optical networks, or PONs, are the most common type of network. They use a minimum of electronics. In fact, there are no electronics at all between the provider's central office and users. This vastly improves network reliability.

Now, as we noted above, bandwidth providers are increasingly bringing fiber optics all the way to customer premises. That technology, FTTH or fiber to the home (also called FTTP, for fiber to the premises or FTTx for fiber to everyplace) is the "gold standard." But in cases where the population density is too low, or where high-quality coaxial cable or copper networks exist, it may make sense under some circumstances to bring fiber only partway to the customer. The fiber is then connected to the existing copper for the last jump to users' premises.

As time goes on, fiber is moved closer and closer to the customers, to provide more bandwidth. That approach is called FTTN for fiber to the "neighborhood" or "node" or (for greater bandwidth) fiber to the curb (FTTC).

Today, the looming bandwidth needs are so large, and FTTH construction prices so reasonable, that going straight to FTTH makes more economic sense.

In the US until now, single-family homes have been the easiest to equip with FTTH. Apartment buildings and other multiple-dwelling-unit (MDU) structures in the US started to be served with FTTH in really large numbers only in 2006. MDU fiber service is already common in Europe and Asia, however. Thus, there is no "technology risk" in specifying FTTH now, in any circumstance.