Accommodating Telecom Variety: Design requirements for communications services entrance facilities

Shutterstock / Irina Orlova
Shutterstock / Irina Orlova
Published On
Jul 15, 2021

In October 2020, I discussed data centers in smart buildings and how it could affect the building design, especially when considering the needs of power-user tenants. I briefly mentioned communications services entrance facilities for the building, but they are important enough to take a closer look at their design requirements.

In doing some online research, I discovered many facility planning documents that were more than a bit out of date. Many are from the era when an entrance facility was a location where large pair-count copper cables came into the building and were connected to wires for plain old telephone service around the building using giant punchdown blocks on a plywood board mounted on the wall. That made me wonder if the documents also called for hitching posts out front for horses!

Newer planning documents include fiber optics, but most assume there will be one or two fiber optic cables bringing service into the building, terminating in a rack of equipment that converts the signals to structured cabling for voice and data. Some mention of coaxial cable from a CATV service provider might be included if the building has residential and commercial tenants.

Today’s reality is much more complex. Phone landlines are being abandoned for cellphones. Over the last year or so, many residencies have become home offices where communication services are being used as never before. Today’s home office demands that fast, reliable broadband and cellular service are available throughout the building, similar to an office building.

In my neighborhood, all the new buildings are mixed use—residential, commercial and retail, so one assumes a variety of communication services need to be accommodated in a building entrance facility. This implies that the old-fashioned model of a janitor’s closet with a single 4-inch conduit to the outside world and a plywood board for 66 punchdown blocks is no longer what’s expected.

The design should be for at least four 4-inch steel conduits for incoming cables. Each of those should have multiple ducts, microducts or fabric ducts already installed to allow the installation of multiple cables, as the number of service providers will likely be increasing over time. Those conduits must connect the indoor entrance facility to an outdoor handhole or manhole, where service providers will bring their cables to connect drops into the building. It’s preferable for this outdoor drop point to be a large manhole since it will probably need to accommodate numerous splice closures for drops off service providers’ cables.

The indoor facility needs to be carefully placed in the building. A corner of the basement may not be a good choice because the entrance facility will probably need space to house several racks of patch panels, telecom equipment and backup power supplies.

Consider placing this important facility on a higher level in the building. This facility must be secure and hardened, with special attention paid to all possible disasters: fires, floods, storms, earthquakes, terrorism, etc. Basements are more likely to be a potential problem area for flooding, which has recently become an increasing concern for many areas. One document I read noted that utilities such as water and drains should not be run overhead in entrance facility or data center areas.

For the entrance facility, consider access to the cabling and communications equipment throughout the building, which can be complex in a multitenant building. It may be preferable to place the entrance facility near the building’s center so it is closer to spaces for riser cables, rather than an outside wall. If it’s a multitenant building, provision for making connections to tenants can greatly simplify the cabling in the building.

If the building has a central equipment room (often called a data center today), moving as much equipment as possible into that area may be preferable, because the entrance facility equipment and data center need the same services: conditioned power with backup, independent climate control for the electronics, fire suppression equipment and entrance security. Location in the building should not be a problem because the service providers will be using fiber optic cables, and those can run for longer distances inside the building with indoor/outdoor-rated cables.

I should repeat the need for security in the entrance facility, and only authorized personnel should have access to it. I know of several instances where sabotage damaged a company’s communication facilities. Keyless electronic entry systems and videotaping of all activity at the entrance and inside the facility is a wise investment.

About the Author

Jim Hayes

Fiber Optics Columnist and Contributing Editor

Jim Hayes is a VDV writer and trainer and the president of The Fiber Optic Association. Find him at www.JimHayes.com.

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