Facts You Should Know About

Wired Intercom Systems for Your

Business

How to Choose the Best Wired Intercom System For Increased

Productivity Without Worry About Choosing the Wrong System.

By:

IntercomsOnline.com LLC
8161 Highway 100, #194
Nashville, TN 37221
888-298-9489

www.IntercomsOnline.com
sales@intercomsonline.com

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Summary
In this guide you'll find information about the different types of intercom systems you'll see
while searching for a system. It discusses technology used, types of wire required, and the
advantages and disadvantages of each type. After reading it you'll be able to better define what
type of system will be best for your application.

Thank you,
David Onslow, Marketing Director
www.IntercomsOnline.com
david@intercomsonline.com

Introduction
As you scroll through the online search results for intercoms, no doubt you've seen a confusing
array of choices for wired intercoms. You are faced with decisions of whether to purchase wired
or wireless; 2-wire, or Cat-5; video or voice only; full-featured or basic features only. You can
even purchase systems that transmit and receive over your house or business power lines.

You're likely reading this because your business has a communication problem and you have the
task of solving it. Also likely is that intercom systems are probably not your area of expertise and
you don't have a lot of time to become an expert.

But the last thing you want to do is spend a bunch of money and waste time on a solution that
won't solve your communication issue. People are no doubt counting on you to get this right.
Their productivity depends on it and the last thing you want is to listen to complaints of
coworkers about the system you choose.

In this guide we'll give you the facts you need to know before you go shopping for the right
system for you. Finally you'll be able to stop the shouting and unnecessary walking to deliver
messages that could be delivered instantly via an intercom system.

Full Duplex or Half Duplex

In voice communications there are half-duplex and full-duplex methods of transmission and
receiving. Half-duplex communication is like push-to-talk "walkie-talkie" radios or CB radios.
When you want talk to someone else with a compatible device, you have to press a button to talk,
let go, and then wait for a reply. The person on the other end does the same to respond to you.
Neither party can talk at the same time.

Full duplex communication is what a telephone uses. Both parties on the call can speak at the
same time.

Wired intercom systems come in both half and full-duplex. As a general rule, most wired base
station-type intercoms that sit on a desktop use half-duplex. Intercoms that use telephone-style

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handsets are usually full duplex. Video intercoms often use full-duplex, but some also can be set
for push-to-talk at the master station.

Door telephone systems that ring your business telephones provide full-duplex communications.
The visitor simply presses a button on the outside door unit and it rings all the inside telephones
on the same incoming telephone line.

Wire Types
There are really only two main wire types used for intercoms. Shielded and unshielded twisted
pair Category 3, 5e, or 6 as defined below.

Shielded Cable
Some intercoms require a cable with a shield around the internal wires. This shield is either a
metal foil or braided wire that keeps outside electrical signals from
interfering with the voice transmission. If you've ever hear a buzz on
an intercom, it probably came from nearby electrical wires that were
running near the intercom wires. To help eliminate this problem,
never run intercom wires in parallel with other electrical wires. If
you have to cross them, make sure it's at a 90 degree angle. The shield will also keep radio
frequency interference of your intercom system.

CAT3, CAT 5e, or CAT 6 cable

Category 3 cable, commonly known as Cat 3 or station wire, is an unshielded twisted pair (UTP)
cable designed to reliably carry data up to 10 Megabits/sec. The data speeds for Cat 5e is 100
Megabits/sec, and Cat 6 is 500 Megabits/sec. Cat3-6 cables are a part of a family of copper
cabling standards defined jointly by the Electronic Industries
Alliance and the Telecommunications Industry Association.

Category 3 was a popular cabling format among computer network

administrators in the early 1990s, but fell out of popularity in favor
of the very similar, but higher performing, Category 5 cable
standard. Since the early 2000s most new structured cable installations are built with Cat 5e or
Cat 6 cable. Cat 3 is currently still in use in telephone systems or low speed Ethernet data
systems.

UTP cable does not require a shield because it has a twist in the wire that cancels out any noise it
picks up along the way.

Types of Wired Intercoms

Below are examples of wired intercom systems you'll find on the market.

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Power Line Carrier Systems
Power Line Carrier (PLC) intercom systems communicate using a very low FM frequency over
your building's existing 110 volt AC house wiring that supplies power to receptacles and light
fixtures. These intercoms are typically passed off as "wireless"
intercoms since you do not have to install wiring between locations
even though they communicate over wire. You just plug them in
anywhere you have an outlet and they're ready to go.

While they sound like the ideal solution for basic applications, most
users are typically not happy with these intercom systems, at least not
for long.

These units are very susceptible to interference from both inside and outside the house or
business. You may experience buzzing, poor audio, or they may work perfectly well for you.
They are very low featured, but they are also very inexpensive. These systems are not
recommended for most applications. Sometimes they work fine until you plug in something like
a laptop computer nearby to charge or some other new piece of electronic equipment like a high
definition flat screen TV. Then you get nothing but static. There are lots of devices that could
interfere with these intercoms, especially in a business environment.

The other issue these intercoms have is that they don't always work in different parts of a house
or business. The electricity in a building comes in as 220 volts and is then split into two phases
of 110 volts each. Half of your building will be on one phase and the other half on the other
phase. The intercom signal traveling over one phase doesn't always make it to the other.

Master and Substation Systems

Some systems like the system shown here have one station that is considered a "master" station,
which means that it allows you to make calls to multiple
substations. The substations can only make a call to a master
station and not to other substations. In some cases you can add
more master stations that can call each other, but then you have
to install cable that has more pairs of wires to accommodate
multiple channels of communication. Other systems have
stations that would all be considered master stations enabling
you to call anywhere, but these are usually Cat 5-type systems.

Cat 5 Systems
Intercom systems that use Cat-5 wiring may communicate digitally
between stations and therefore usually offer more features. Cat-5e
wire is readily available in building supply stores as home builders
routinely install it for computer and telephone networks.

The systems available for CAT 5 are usually residential systems

that may not have the features needed for a business installation.
The one pictured here has been used in business applications but it
does not have enough volume for noisy locations.

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If you need all station-to-station communication for your business like a Cat 5 system can offer,
then it may make more sense to look into purchasing a telephone system with intercom
capabilities.

Voice Over IP Systems

A new category of intercoms uses the Voice over Internet Protocol (VoIP). This protocol is what
services like Skype or Vonage use to deliver telephone calls over the Internet. With a VoIP
system you could literally make intercom calls across the world if you have a good enough data
connection. VoIP systems usually require virtual private networks (VPN) to give the quality of
service (QoS) required to give acceptable performance. VoIP intercom systems are usually used
on a businesses' private Local Area Network (LAN).

VoIP systems can consist of not only hardware like desktop or wall mounted intercoms, but also
software on a computer that can talk to them.

Installation of VoIP systems is much more complex and will likely require trained networking
staff to install. VoIP systems are also much more expensive as well.

Video Systems
In their most basic form a video intercom has an audio only substation with a camera that goes at
the door or entry, and a master station with a video monitor that goes inside. You can also get
systems that support multiple doors and multiple inside stations.

There's a big difference in the price range of these units. If all you need is a simple picture of
who is at the door, you can get black and white monitor units very cheaply. If you need
something that's vandal-proof and fully featured, the price goes way up.

Some features you may want to consider: image picture memory or video capture to record who
visits, video to DVR output for security video purposes, wide 170 degree angle view, vandal
resistant camera, higher image quality, and digital camera pan/tilt/zoom.

If you are mounting the camera and monitor at a school, you may want a unit with the tilt feature
since the visitors are going to come in all sizes. The viewers will have to raise the tilt for an adult
and lower it for a child. Going with a vandal-resistant camera would also be wise in this
instance.

Video intercoms typically only require a 2-wire installation. The wire types vary from CAT 5 to
non-shielded, solid 2 conductor.

The distance between the camera and the monitor is usually limited to around 300-400 feet. One
unit has a range extender that enables it to go to 660 feet.

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What to do Next?
If you still have questions about choosing the right system for your business, call
IntercomsOnline.com at 888-298-9489 to request a free consultation with one of our product
experts. We'll listen to your communication problem and then try to come up with the best
solution for it, whether that's products we offer, or those we recommend from somewhere else.

We've helped businesses save thousands of dollars of expense from choosing the wrong intercom
and we've helped countless businesses to improve their communication, and therefore their
productivity. We're pretty sure we can help your business too. Thanks for reading this guide!

Partial List of IntercomsOnline.com Customers

1&1 Internet, Inc. Alaska Dept of Fish and Game Alcoa Fastening Systems
Amazon.com American Embassy Ball Corporation
BASF, The Chemical Company Bayer Cropscience Bausch & Lomb
Boston Scientific Chevron Products Company Chevron Corporation
CITGO Petroleum CN Railroad Coca-Cola Enterprise Bottling Co.
Costco Dow Chemical Fairchild Communications
Federal Aviation Administration Federal Bureau of Investigations (FBI) Frito-Lay, Inc
GAP Inc. (gapinc.com - clothing) General Dynamics General Motors Powertrain Global HQ
Georgia-Pacific Goldman Sachs Gorton's
Harley-Davidson Financial Services, Inc Harvard University IKEA Furniture
Internal Revenue Service (IRS) Jos. A. Bank Clothiers, Inc. Kohl's Distribution Center
Level 3 Communications Lockheed Martin Marriott Hotels
Mayport Naval Station Monsanto NASA Goddard Space Flight Center
National Park Service National Weather Service, Alaska Nissan Trading Corp
Ohio State University Owens Corning Parker Hannifin-TechSeal
Pepsi Bottling Group Pine Bluff Arsenal Procter & Gamble
Sea World Florida Social Security Administration Target Corporation
The Boeing Company The Ritz-Carlton The Wackenhut Corporation
Toshiba America Information Systems Toyota Technical Center Tyson Foods, Inc.
U.S Coast Guard U.S. Air Force U.S. Army
U.S. Army Special Operations U.S. Army, Camp Marmal, Afghanistan U.S. Border Patrol
U.S. Forest Service (USFS) U.S. Navy U.S. Post Office
U.S. Secret Service University of Iowa University of Michigan
USAF Space Surveillance USDA Forest Service Verizon
Veterans Administration Virginia Tech University Whole Foods Market
Yosemite National Park Service Zatarain's

What Our Customers Are Saying

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"I want to thank you, and your company, for this invaluable service you continue to provide. You have been much more than just
"normally" available and supportive. As soon as we realized that a device wasn't responding like it had been, I was confident in

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the knowledge that you would be available to answer questions if they were within your realm. That is a valuable service, and all
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"Before ordering a pair of intercoms for elderly relatives, we called customer service and got excellent help and the advice we
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would recommend IntercomsOnline.com to anyone who is looking for intercoms. I will certainly use them again. The Call
Forwarding Controller was exactly what I needed. It did take a bit of time to work out the technical details but everything worked
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your excellent service." Maria Pineda, Miramar, FL

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