THE CHALLENGE

In the earliest FiOS years, Verizon actually shied away from MDUs because of the difficulty of wiring individual apartments, said Bill Belden, director of network solutions for Verizon. “Getting fiber all the way to the living unit was a problem,” he said. “Creating that pathway in existing MDU buildings was a high challenge from a technology perspective and a cost perspective and the perspective of getting the owner's acceptance.”

Compounding the problem was the fact that every building had its own unique design.

“Building architects are like artists. They want to add a special touch to each one to make it different,” Belden said.

Those special touches made each building a challenge. Owners and renters alike expect any cabling to be installed with as little disruption as possible and for the final product to be aesthetically pleasing.

For the FiOS program, that was doubly problematic, Belden said. Installing fiber in tight spaces was difficult because fiber traditionally couldn't be bent to go around corners, and the first optical network terminals (ONTs) were designed to hang on the side of a house, making them too bulky to easily sit inside an apartment, where space is at a greater premium.

Within the last year, however, an increase has occurred in the availability of fiber that can handle sharper angles, sometimes called reduced bend radius fiber.

“The reduced bend radius fiber itself is generally able to be bent; it has a much smaller bend radius than traditional single-mode fiber, without increasing attenuation,” said Trevor Smith, program manger for fiber-to-the-x solutions for ADC Telecommunications. “It's also sometimes called bend-optimized or bend-insensitive. There are a number of technologies that allow you to do that, and a number of glass manufacturers can do it as well. It's not all that new.”

In fact, this bendable fiber has been deployed in fiber-crazy Japan for years, specifically to meet the needs of high-density MDUs prevalent in Japanese cities. But what the Japanese deployed is not backward-compatible with the single-mode fiber that is widely deployed in the U.S. and elsewhere, Smith said.

“Until a year and a half ago, no one was able to manufacture backwards-compatible and small bend radius fiber,” he said. “In Japan, either the building was brand-new or they were willing to pay the premium. Outside Japan, reduced bend radius fiber was used only in very specialty applications as well.”

Companies such as ADC and Corning Cable Systems now sell this bendable fiber in rugged jackets or cabling that make it much easier to install in tight spaces, and they are finding the biggest demand for the new products in the MDU space.

“The first application that appears to hold the most value is in fiber-to-the-premises MDU deployments, particularly for drop cable,” Smith said. “We didn't realize how much this was on their minds until the last three to six months when we started to market this thing. Our customers have said, ‘We've been avoiding MDUs for FTTP because we didn't have a solution.’ This fixes it. It allows us to start addressing that market.”

Corning's ClearCurve fiber cable was designed to handle the rigors of demanding installations — something that potentially makes it a good fit for MDUs.

“Our ClearCurve cable has two fibers, and it's a rugged drop cable for greenfield applications, where the frame is up there and it's a relatively harsh environment,” said Bernhard Deutsch, director of marketing and market development for Corning. “Installers want to treat it like copper cable. They want to bend it in and staple it in, and that's where the really reduced bend rate of five millimeters comes in.”

The fiber cable is self-bend limiting, so it can be bent too far by the installer, Deutsch said. “It's not indestructible, but it is very robust,” he said. “It can make tight 90° bends for a hallway, and it can fit into a very small crown molding — they don't want large pathways for the cable in an apartment.”

The new cabling enables installers to more easily and rapidly take fiber all the way to individual apartments in a building, which cuts installation time and cost, making both the telco and the landlord happy.

Verizon previously had used microducts, which its technicians installed in advance, to maintain the fiber's bend radius so it wasn't bent beyond its limits, creating signal loss, Belden said.

“In a high-rise, we had hallway molding systems, and we used bend radius guides because the typical hallway isn't as straight as it looks,” he said. “We would have to be very careful with the fiber. Now the jacket itself limits the ability to violate that bend radius. We don't have to use microducts. We know it can save a work step, so we know we are more efficient and can hopefully save costs.”

Because of the time and labor efficiencies, Corning has estimated 35% to 40% in cost savings for MDU deployments, even though the fiber itself costs more, Deutsch said.

Next page: THE BIG PUSH