Workin’ Those Connections

When working to deliver FTTx to MDU residences, the devil is in the details. The ideal solution is to develop a design that meets not only your delivery needs, but also works with the unique requirements of the MDU. It’s important to keep in mind that the tenant’s interface with the technology should take priority as this can increase both demand for new services as well as improve the value of the property itself. Unfortunately, it can also be the source of most service problems.

A Typical Mid- to High-Rise Greenfield Installation
Whether a greenfield or a brownfield MDU, systems for either can be easily housed and managed within an enclosure or cabinet, such as a structured wiring enclosure. The ONT handling the incoming fiber and the distribution modules handling the home’s copper wiring should be located in close proximity, ideally in the same enclosure or cabinet. (See Figure 1.)

Another popular configuration places the ONT and distribution device in separate enclosures, either in the same stud bay or immediately next to it for separation of the wiring access. This enclosure is called a sister cabinet. (See Figure 2.) In addition to providing a central location for servicing and wiring access, it protects the equipment in a dedicated space, keeping it enclosed and out of sight. Of course, the enclosure should be UL-rated and provide proper power and grounding options for active elements.

Fiber to Copper: The Hand-Off
Where fiber meets the living unit’s copper wiring there must be some form of optical-to-electrical signal conversion as well as a physical distribution point. It is here that one signal is split or multiplied to several in order to serve the home’s many outlets. In most cases, the incoming fiber is fed through a protective flex tube and enters the ONT or ONT enclosure. (See Figure 3.)

Once the optical signal is converted to an electrical one, the voice, data, and video signals are transported over twisted pair, CAT5e or CAT6 preferably, and coax. As the ONT has a limited number of outputs, distribution to the home’s outlets requires some additional premise distribution equipment.

Wiring at the Living Unit
Another consideration is how the resident is ultimately served from the ONT through connections made to the jacks and then ultimately the customer’s multimedia devices. Given that we are living a highly connected lifestyle, end users today rely on the Internet for access to vast amounts of information, entertainment, and social networking. And as expected, the number of consumer electronics devices requiring network connections is now staggering. This, of course, is making home connectivity solutions more critical than ever before. For this reason, builder/developers and building owners are now providing generous connectivity options to their residents.

Getting new fiber to each living unit is the time consuming task. As is typical of medium to large MDUs, a fiber distribution hub (FDH) is located in the basement or in a common equipment room. A fiber feeder cable from the central office services the FDH which, in turn, organizes and administers fiber optic cables and passive optical splitters.

Because the FDH is indoors, it does not require the environmental protection that an outside-plant FDH would require. Here, the FDH is located at the utility entrance of the building with fiber distribution cables going to fiber distribution terminals (FDTs) on each floor. The FDT manages dedicated fiber drop cables to individual customer living units. The fiber is then fed to the ONT either at each unit or in the central wiring closet.

In a new building, for example, high-speed Internet, video, and phone wiring is most often managed within each unit via a structured wiring enclosure that distributes wiring to outlets or consumer electronics. In an overbuild situation, new fiber may be brought into the residents’ home and an entry coat closet may take on a second role as a wiring closet.

Fiber to Copper and Distribution
The devices that distribute the wiring to multiple outlets are called distribution devices or modules. The most common building method today places these devices or modules in a recess or wall mounted enclosure (Note: This enclosure can be called the structured wiring cabinet/panel, common wiring panel, or media panel. This enclosure provides a clean, efficient, and serviceable location for moves, adds, changes, or repairs to the network.

Once the fiber is terminated to the ONT, the incoming optical signal is then converted into an electrical signal and must then be distributed throughout the living unit. In this case, all three services (phone, Internet, and video) are run from the ONT cabinet to the adjacent structured wiring cabinet where each service is then connected to the appropriate distribution module which, in turn, splits or multiplies their respective signal to all wallplates throughout the residence. (See Figure 4.)

To ensure the residential network can be utilized to its full potential, the cable runs and outlets have been configured robustly. Each cable drop is made up of 2 CAT5e cables for phone or Internet, and 2 RG6 coax cables for video. There are multiple wallplates in every room and each location has 1 phone jack, 1 data jack, and 2 video connectors.

KISS: Following the Guidelines and Standards
The primary industry resource for wiring standards best practices is the TIA standards group. These standards define the best practices for design and implementation of copper and fiber cabling systems for commercial and residential dwellings. They deliver specific information on cabling types, distances, connectors, installation requirements, performance characteristics, and testing.

It is important that The National Electrical Code (NEC) is followed for all installations because a copper network can carry electrical current in the case of a lightning strike. It is also very important that the products selected comply with Underwriters Laboratory (UL). This ensures that the selected product has been tested and meets applicable industry standards since the equipment is located inside a wall in many circumstances.

TIA-570-B (Residential Infrastructure Cabling) Standards are divided into two grades:

Grade 1. This cabling meets the minimum requirements for basic telecommunication services. It supports basic services including telephone, satellite, CATV, and data service. Briefly, it outlines:

• One 14" (or larger) enclosure from which to star-wire the home, with a surge protected electrical outlet.
• One CAT 5e (or CAT 6 recommended) and one coax cable and connectors to every outlet in the home.

Grade 2. This is a better cabling system that meets minimum requirements for basic services plus advanced telecommunication services including high-speed Internet access and video services. Briefly, it outlines:

• One 28" (or larger) enclosure from which to star-wire the home with an surge-protected electrical outlet required.
• Two CAT 5e (or CAT 6 recommended) and two 75Ω coax cables and connectors to every outlet in the home.

Conclusion
If the goal of the service provider and the property owner is to grow the average revenue per user (ARPU), the end user's experience and facilitating broadband usage in the MDU is critical. It's no long The Last Mile that is the problem, it's the Last 50 Feet which can make or break that experience. However, with proper planning, the service providers along with the MDU builder/developer can both reap profits by delivering an in-home network that delivers on the promise of what fiber can bring.
 

About the Author
Jay Kilby is Director of Marketing at Suttle, a provider of wall-to-wall connectivity solutions for delivery of Triple Play services to the residence. In his previous position he was responsible for developing the SOHO Access™ brand of residential structured wiring now deployed within several major service providers. You can reach Jay at 800.818.8531 or jayk@commsysinc.com.

Suttle provides a variety of wall-to-wall solutions for delivery of Triple Play services to the residence. Product information and technical specification sheets are available at www.suttleonline.com or 800.852.8662.

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