Why is everyone so stoked about fiber-optics? Clearly in this world of more HD, capacity is its biggest calling card. High-speed Internet and high-definition video are pushing bandwidth requirements to 20-25 Mbps for each user, and it's anticipated that it could increase to 50-60 Mbps per user by 2010. Although more efficient compression schemes, such as MPEG-4 and VC-1, and new technologies, such as switched digital (which treats all programming like video-on-demand) are helping cable deal with the bandwidth required for more HDTV content, many cable networks are currently strained to capacity, unable to offer more HD without cutting back on other services, such as analog channels. That's why the theoretically nearly limitless bandwidth of fiber-to-the-home (FTTH) networks, such as that employed by Verizon, is so appealing. Although FTTH is much more expensive to deploy than systems that use fiber in only parts of the distribution system, it currently provides about four times more bandwidth of those other systems, with unshared data streams up to 100 megabits per second (Mbps).
"In the last 20 years in data communication, there's been one axiom: the amount of bandwidth people are consuming today will be materially less than what they'll want tomorrow," says Brian Whitton, executive director of technology for Verizon's Access Network Design and Integration Group. And because fiber-optic pipes can carry so much data, he says, when Verizon wants to mine more bandwidth from its network, all they need to do is change the lasers on the end points of that fiber cable. "That's important because of simple economics: Labor will be more expensive tomorrow than it is today, and a laser will be cheaper. When we need to increase the productivity of that fiber, we can simply upgrade the network on both ends without using labor."
Still, the cost of building a completely fiber network can be staggering. For example, Verizon anticipates spending $23 billion on its network through 2010. But because the system is passive - more on that later - there are no active or powered elements between the main office and the customer. Result: Operational costs, including maintenance, are dramatically lower than copper-based systems, which require multiple RF amplifiers along the line. The active elements can not only add noise and distortion to the signal, they're also subject to mechanical failure.
In addition, according to Whitton, many of the elements in Verizon's fiber-optic system are self-diagnostic, enabling the company to proactively monitor the network, thereby boosting reliability. "The devices in our networks have processors in them, and they've been designed from day one to sound an alarm if something goes wrong so the customer isn't impacted," he says. Often, he says, issues can be resolved remotely, without a service technician being called in, whereas "cable companies find out there's a problem when their customers call in and tell them." That type of efficiency can also yield financial benefits: Verizon expects to recoup $5 billion of its investment in lower operating costs through the end of the decade.
There are several other advantages to fiber. For one, unlike electrical signals sent over copper wire, light pulses aren't susceptible to the same kinds of electrical interference or crosstalk between channels, which can impair video quality. There's also less signal loss, particularly when traveling over long distances, and since electricity doesn't pass through the wires, fires are less of a concern. And fiber optic cables are smaller, lighter and more flexible than copper-based cables, making them more efficient to pull and distribute.
Copyright © 2013 Bonnier Corp. All rights reserved. Reproduction in whole or in part without permission is prohibited.