Feel more secure with wired cameras? Here's why it's safe to consider cutting loose
Written by Neil Sutton, on Thu-February-2008
Wireless networks transport signals through thin air, but that doesn’t mean camera security has to be lightweight.
In theory, a wired camera install should be more secure than wireless, since the signal travels within given physical parameters. Wireless information is necessarily more exposed, but this needn’t make it any less secure, according to experts in the field.
Wireless: Where to deploy it
There are three scenarios in which wireless is preferable to wired,
says Jeff Johnson, president of Videocomm, based in Oakville, Ont.
• An area where it’s physically impossible to run cable, like across a
busy street or in a historic building where drilling or cabling would
not be permitted
• An area that would make cable too expensive, like covering a parking lot with security cameras
• An area where you want to maintain a clean appearance, i.e., no unattractive wires
Johnson says his end users tend to be schools, property managers,
facilities, and parking lot operators. He has also sold to military,
law enforcement, and even dentists.
For the technology to operate, it requires line-of-site. Unimpeded,
wireless signals can travel for miles. Johnson says that 801.11n
signals using orthogonal frequency-division multiplexing (OFDM) — an
802.11 end format, which allows us to transmit real-time video at high
definition quality — might be able to travel as far as 64 km.
But most deployments won’t be a best-case scenario. Trees, buildings
and other obstacles are bound to get in the way, at least over long
distances. Indoors, Wi-Fi signals have to overcome barriers like
furniture and office walls. Johnson says he can’t really predict how
far a signal might travel without first assessing the situation – every
deployment is different and comes with different challenges – but
wireless signals are not unlike sound waves, he says.
“If you were singing happy birthday at the top of your lungs and I was
in the office next door to you, I could probably hear the words. Three
offices down the hall, I could hear you singing but not necessarily
make out the words. Ten offices down the hall I could probably hear a
noise but not know whether it’s singing or anything,” he says. The same
is true of wireless signals.
Pipe down: bandwidth considerations
The main drawback to wireless camera installations continues to be bandwidth limitations.
“Video is notorious for consuming large amounts of bandwidth – two to
three mbps using MPEG 4 per stream. That adds up quickly,” according to
Michael Martin, a senior managing consultant at IBM Canada who has
helped design wired and wireless networks (and those that integrate
both).
Piping in Gigabit Ethernet is not a problem using more conventional
wired security systems, he says. But with current Wi-Fi standards, “we
might only get 26 mbps of net payload.”
The good news is that wireless networks are beginning to catch up.
Where previous wireless protocols (such as 802.11b and 802.11g) have
been met with severe limitations, 802.11n promises to level the playing
field and could be the technology that allows users to move beyond
Ethernet LANs.
Development of 802.11n slowed down last year due to patent issues, but
experts believe it should be a workable standard sometime in 2009. The
promise of 802.11n is “significantly better bandwidth – up to six to 10
times greater than 11g,” says Martin. “As a result we might see
bandwidth in the neighbourhood of 300 to 800 mbps.”
Until we reach that threshold, however, conventional wireless
transmission means are still more than enough for some users, depending
on their requirements. For example, 802.11g can still yield a maximum
throughput of 54 mbps using OFDM (orthogonal frequency-division
multiplexing).
Network security revisited
As previously mentioned, security is not necessarily an impediment to
wireless CCTV. Provided the appropriate precautions are taken, it need
not be any less secure than the majority of wired systems.
“The security issue used to be totally in favour of wired, but that’s
becoming less of a concern because the IEEE and the IETF (Internet
Engineering task Force) and other bodies have worked very hard to
develop secured wireless,” says Martin.
Provided that an installer takes the time to set up the network
properly and encrypts the video data, the security of that data should
not come into question, he says. Network data is secured through
firewalls, encryption and network address translations. The same
techniques can be used to secure wireless information.
“The problem we have, is that when we visit sites and look at
installations, many of them don’t manage the (network) security very
well or manage it at all. If you have the security and you don’t use
it, it’s of little value,” explains Martin, adding that the same is
true of wired, as well as wireless, networks.
“Obviously it (security) needs to be there up front and then you maintain it over the lifespan of the network.”
The health of the network also depends on how it is being used. If
video traffic is being run on a separate network, its security can be
micromanaged without concerns about how other systems are affected. But
if video traffic shares a network with other applications, like e-mail,
then it can be delicate balancing act.
E-mail is an example of “bursty traffic” – data is sent in periodic
bursts. Video, on the other hand, is contiguous. “It’s like Niagara
Falls, it’s a humungous amount of volume and it’s coming at you 24x7,”
says Martin. “Depending on how much volume there is, it can be done
well, but the video can also be like an 800 lb gorilla and it can
impact your traffic.”
At this point, the lines between IT manager and security manager tend
to blur – a situation which can make both camps start to feel uneasy.
“We have a world where we have IT directors teaming up with directors
of security and the two have never really worked as a team before. They
each their own perspectives and so there’s been some issues that have
to be resolved – particularly the nature of video on a network,” says
Martin.
But the reality is that physical and IT security are beginning to
merge, particularly as wireless begins to become the preferred mode of
camera surveillance.
Installations are becoming “more IT heavy than screw driver-, volt meter heavy,” cautions Johnson.
“As the technology advances, you’ll need to have an IT background to
install and execute some of the devices,” he says. “If you hook up a
wireless or Wi-Fi data bridge that you want to access remotely over the
Internet, well now you’ve got to call your IT guy, who needs to open up
ports and firewalls and give you IP addresses – all kinds of things
that even someone like myself might have trouble with.”
Best of both worlds
Wireless is bound to become more dominant over time, particularly as
bandwidth shortcomings are addressed, says Martin. But wired technology
isn’t about to disappear. More likely, we’ll see the emergence of more
hybrid networks that utilize both, depending on cost parameters and
project-specific needs.
“You shouldn’t think of wired and wireless as mutually exclusive,” says
Martin. “I’ll use wireless as the last mile and wire an optical fibre
as my distribution layer and my core network layer. To me, I look at
what’s the right tool for the right job.”
