Making a Building Fiber-Ready - Broadband Communities

Posted by Brad Randall | Oct 1, 2018 | Magazine Archive, Multifamily, TECHNOLOGY

The case for fiber in the building is clear. Fiber is the most future-proof communications medium available. It attracts residents, and it’s less expensive, easier to install and less intrusive than copper and coax cables.

The question in many building owners’ minds is, “How do I make my building fiber ready?” This article is a condensed version of the white paper of that name published by the Fiber Broadband Association (FBA). For more information, please reference the full paper at the FBA’s website (https://toolkit.fiberbroadband.org/d/do/2639).

If at least one fiber passes or enters each living unit, a building has fiber to the unit. More than one fiber per unit may enable future services or multiple carriers to service the building. To accommodate future requirements, the FBA recommends that the number of fibers in the riser be 1.5 times the number of living units.

The fiber type is critical. Single-mode fiber is recommended for in-building fiber networks, and because buildings contain many corners and bends, bend-insensitive, single-mode fibers are recommended. For risers, fibers meeting or exceeding International Telecommunication Union (ITU) Recommendation G.657.A2 are recommended. For drops down hallways and inside units, fibers meeting ITU Recommendation G.657.B3 are recommended.

Building owners have a choice regarding the scope of their involvement in network preparation. Compared with the construction of an entire building, fiber installation is a very small and inexpensive part. Typically, a building owner fulfills one of two roles:

If a building owner chooses to put in the network, close communication with the service provider is important to make sure the service provider will be able to use the network. For example, connector types must match, conduit sizes must be large enough, and power and cooling requirements for any active components must be met.

A typical architecture of a fiber-to-the-unit MDU network is as follows:

All conduits and cables must meet appropriate flame and smoke ratings. The National Electrical Code (NEC) is a main source of information regarding requirements, although local codes may also apply.

Spaces are needed in a building to house various pieces of equipment and connection points.

Pathways for fiber placement are critical. The fiber pathways needed to new buildings versus already occupied buildings can be quite different from one another. Pathways can be either indoors or outdoors, are typically designated as “riser” or “drop,” and must be large enough to accommodate the cables needed to reach living units. There can be different pathway scenarios for different building designs.

For new buildings, the easiest approach is to place conduits or microducts with pull strings in the riser and to each unit during building construction. The pull strings can then pull cables into place as needed. Typical conduit sizes are 1 inch or 2 inches for risers and ½ inch for drops, but these should be confirmed with the service provider to make sure they are properly sized.

In already occupied buildings, conduit placement is not often possible without extensive renovation, but there are many alternative ways of making pathways, including placing cables above drop ceilings or moldings, mounting small cables on wall surfaces, or running cables up the outsides of buildings into individual units. Fiber optic cables can be very small, and in many cases, the visual impact can be small.

Cables come in different structures and fiber counts. Most fiber optic cables are typically less than 1 inch in diameter, although some cables with hundreds of fibers may be larger. If the building owner is to purchase cables, be sure to discuss the proposed network architecture and fiber and cable types with the service provider to confirm cable and fiber types, fiber counts and the connection plan.

Property owners can choose from a variety of products and techniques to make their buildings ready for fiber services.

Fiber in the unit is connected to the fiber in the hallway (or outside). It is then installed in the unit and typically terminates in an optical network terminal (ONT), which converts the optical signal to an electrical signal. The ONT is typically located near AC power. Other devices supplied by the service provider may include a battery backup unit, a router and/or switch, and TV set-top boxes. ONTs are often either desk- or wall-mounted.

As residents are sensitive to the visual footprint of cables, fiber products used in the unit are typically more aesthetically pleasing than those used in risers or closets. Smaller cables and cords are often used. Fibers meeting ITU G.657.B3 are recommended for this application because of the many bends. Fibers are often installed near the ceiling to reduce incidental contact. Methods of installation include stapling, surface-mounting or track-mounting on walls. It’s best to discuss the in-unit components with the service provider in advance and to coordinate the installation path with the resident so everyone is satisfied with the installation.

The Fiber Broadband Association believes that every building and living unit should ultimately have fiber. Millions of apartments and condominium units have already been wired with fiber, and service providers and manufacturers have developed products and techniques to easily and cost-effectively wire the vast majority of buildings.

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