When you’re
shopping around for an IP-based video surveillance system, you
will need to be particularly cautious about what exactly you’re
looking at and what the individual terms mean. How IP-based video
surveillance works is open to interpretation as far as some video
surveillance and security salespeople are concerned -- not because
they are trying to confuse the issues, but because there is no
genuine consensus on what the term “IP-based” or related
ones such as “networked” or “web-based”
means.
Originally
video surveillance was done based on analog technology -- closed
circuit television (CCTV) and recording on video tapes. This was
fine for recording what was going on, but it didn’t broadcast
actual live information, so it wasn’t practical for monitoring
stores, for instance, from a remote location. It simply provided
what happened after the fact. The picture quality wasn’t
great and it relied on human reliability as well -- someone had
to remember to change the tapes regularly, etc.
Digital
revolutionizes video surveillance
With the Internet
revolution and the ever-increasing presence of Local Area Networks,
technology took great strides in video surveillance in the 1990’s.
Analog camera tubes were replaced with CCD (Charged Coupled Devices)
and digital cameras became affordable for most people.
This combination
meant that video surveillance could do two things: go live over
the Internet or a closed network for surveillance and provide
clearer, crisper images that could be tracked and manipulated
easily. For law enforcement, digital surveillance meant it was
much easier to zoom in on images, track particular scenes and
enhance features.
The
basics of IP-based surveillance
A digital
camera “views” the scene in front of it, broadcasts
the video images as a digitized signal over a LAN line (Local
Area Network) where it’s then transmitted to a computer
or server. The server in turn manages all of this information.
Depending upon the software used to manage the digital images,
it can record, display or retransmit the images to anywhere in
the world.
The software
package can easily be upgraded to allow for analyzing data, selecting
specific “flagged” items to watch for and a host of
other functions, making it a truly customizable security tool.
True IP-based
digital surveillance uses CCD cameras that use signal processing
that send packetized video streams over the LAN through a Cat
5 cable rather than a coax cable network, utilizing greater bandwidth
and standard TCP/IP communication.
It also provides
more intelligent data mining and information retrieval. If security
is an issue, full digital surveillance also offers the added advantage
of data encryption opportunities to protect against image tampering
-- something not possible with analog recording.
Recently,
a few companies such as D-Link and Linksys have also developed
fully digital cameras that actually have completely integrated,
built-in web servers so that no external computers are needed
for operating them. The signal is transmitted directly to the
terminal location for storage or play-back.
Halfway
there…
The “middle
of the road” of video surveillance is upgrading video surveillance
by utilizing a Digital Video Recorder (DVR). A DVR system is not
really fully IP-based, but is step toward the more advanced IP
technology. In actuality, a DVR system uses the same camera and
structures for cabling as the older CCTV analog systems, but the
old VCRs have been replaced with DVR for storage of the data.
The data is converted to digital so that it can be stored on hard
disks, but the quality of the images captured remains analog since
this is how it originated.
When shopping
for a system, be sure to ask if the system is digital based on
the recording (DVR) or on the camera, since many manufacturers
consider a system digital by virtue of the DVR storage system
even if the camera recording the images is still analog.
Going
all the way
Some people
will move to the hybrid models of a CCTV/DVR system when they
first move beyond an analog system because it seems like the next
practical evolutionary step in video surveillance. However, shifting
to this method largely ignores how IP-based video surveillance
works.
With CCTV/DVR
surveillance you have actually simply delayed the inevitable by
adding on a relatively new technology (hard disk, digital storage)
to an old technology (analog video over coaxial transmission lines).
Rather than moving forward into something new, you have prolonged
the demise of the old.
Advantages
of IP-based video surveillance
The leap into
completely IP-based technology is the best bang for your buck
both monetarily and in terms of security by far. Digital surveillance
can be done over a LAN network, of course, but TCP/IP transmittal
of surveillance makes sense for remote monitoring of multiple
locations and for remote recording of data onto back-up servers
and hard disks for long-term storage.
With IP-based
video surveillance, you can connect your surveillance camera or
cameras to any network or wireless adapter, and you are extremely
flexible in your placement of the camera itself. A typical PC-attached
video camera, while providing digital picture image quality, still
has to be within approximately ten feet of the computer itself.
Set-up of
an IP-based video system is easy -- once you’ve set up an
IP address, you’re up and running and it’s extremely
stable and reliable. Because this is the technology of the future,
it is also upgradeable. You won’t be outgrowing an IP-based
video surveillance system any time soon because new developments
are based on improving this market. Therefore, you will be able
to add on and improve this system for years to come while older,
CCTV+DVR hybrids will dead-end and become obsolete.
Comparing
analog and IP-based video surveillance
A better way
to understand the differences between analog and IP-based video
surveillance may be to compare the two and how they work:
Analog
or CCTV+DVR video surveillance
- Easy to
use -- operates like a VCR
- Changing
cassettes and rewinding regularly means human error frequently
interferes with effectiveness
- Image quality
is poor
- Storage
tapes wear out over time
- Broadcasting
images live isn’t practical
- Storage
is bulky
- Uses analog
recording, recording in low-grade picture quality and inability
to search and track easily
- Adding
DVR systems must be done in ‘blocks’ of 16 channels
IP-based video surveillance
- IP-based
recording means instant transmittal of images anywhere in the
world
- Can monitor
multiple cameras from one remote location
- No decrease
in recording quality over time or with repeated replays
- Digital
picture quality far superior to analog
- IP-base
recording is highly compressed for easier storage and can be
transported over a variety of media
Digital images can be encrypted for security purposes
- Updates
and add-ons are relatively inexpensive through software packages
and Internet computer networking
- Adjustable
frame rates
- Remote
or shared viewing may be done over the Internet or a wireless
connection
- Standard
IP video compression techniques are used
- IP surveillance
cameras may be added individually or in groups according to
your needs
If you are
contemplating increased or upgrading video surveillance for your
company or home, understanding how IP-based video surveillance
works will make your decision easier. It is the future of video
surveillance and, although in the short term may be a bit more
expensive, is obviously an investment in superior quality and
flexibility.
