The market is being whipped into a frenzy by buzz about IP,
yet studies show that only 10-15% of systems sold include IP cameras. What’s
the deal?
One firm was recently retained by a new client to provide a
strategic review on the electronic security industry. This client was focused
on CCTV, and inevitably the topic of IP-based CCTV systems was high on their
list. They had studied all of the market data they could find and were
disappointed to discover that — depending on the estimates — only 10-15% of the
systems being sold today are considered IP systems. “How can this be?” they
asked. “Aren’t all systems today essentially IP based systems?”
They were right. Unless you are using a videocassette-based
system or an extremely low-end DVR, all systems are IP based. Why? Because the
recording is handled by a DVR, and that DVR virtually always includes client
software that allows you to remotely access live or recorded video. So, if all
systems are IP eventually, why is there so much discussion as to the pros and
cons of IP based systems?
Close to the Edge
The real question is how far out to the edge do you go with
IP. An IP system converts an analog video signal to a digital stream that can
be transmitted over a conventional Ethernet network. But it can do this in a
number of places.
If an IP camera is used, the signal is converted at the
camera itself — this is what is commonly referred to as an IP-based system. An
analog camera can also be used, and the signal can be fed into an IP encoder
that converts the signal to a digital stream. The IP encoder can be located in
a more convenient location, and multi-channel encoders are available to convert
multiple cameras from one box. Or the camera can remain analog all the way to
the recording device, which then converts the signal to store it. In that case,
the recorder is also serving as an encoder, and the signal is generally
available as an IP signal streaming from the recorder.
So, which system should you use? In general, we recommend
that analog cameras be fed to IP encoders unless megapixel resolution is
required. We base this on a number of factors, including cost, ease of
installation and appearance.
1. Cost — In general, the cost of an analog camera
plus an encoder is generally the same price or less than the cost of an IP
camera, and technically the signal quality is identical. In fact, if
multi-channel encoders are used the cost of the analog/encoder pairing drops
significantly below the IP camera cost.
The true savings come in when you look at replacement cost.
Edge devices fail or get damaged from time to time. One of our clients had a
faulty camera installation and the outdoor IP camera filled up with water
during a storm. Replacement cost was $900, but it would only have been $300 if
an analog camera had been used and connected to an encoder that was safely
installed in a closet or other weatherproof space.
2. Ease of Installation — An IP
camera has some installation limitations that can drive costs up significantly.
Primarily is cable distance — IP cameras are limited to 100 meters (328 feet)
unless special converters, repeaters, or fiber optic cable is used. Analog
cameras can run for great distances before being converted to IP — over a mile
if the proper UTP (unshielded twisted pair) baluns are used. The same cabling
can be used, so cable cost isn't an issue, and the convenience of locating
equipment where conditioned space is available often outweighs other concerns.
Other installation factors include the sensitivity of IP
cameras to power fluctuations, the difficulty in getting environmentally
hardened IP equipment, and the limitations in size and form factor for IP base
products.
Finally,
analog cameras can be plugged into a portable monitor for setup, focusing, and
field of view adjustments. While some IP cameras also include analog outputs to
allow this, many do not. This makes installation far more difficult, involving
a computer, extra network port (if power-over-Ethernet is used) and added time
and complexity when installing.
3. Appearance — We are currently in the golden age of analog
cameras in that the variety of sizes, shapes, features and performance levels
available at low price points has never been better. This gives the designer or
installer tremendous flexibility in matching cameras, housings, lens types, and
other specification features to capture exactly the image that is needed. Too
often, IP cameras require aesthetic or performance compromises that do not go
over well with end users.
While these and other advantages make us lean in this
direction, nothing trumps technical requirements. If your application makes IP
cameras advantageous, feel free to mix and match or use whichever makes the
most sense. As far as which type of device to use, keep both in your toolbox
and remember the old adage; if the only tool you have is a hammer, pretty soon
everything looks like a nail.