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.
This produces more intelligent data mining and information retrieval. If
security is the matter, full digital surveillance also offers the added advantage
of data encryption opportunities to protect against image tampering — something
not possible with analog recording.
Lately, 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.
The fact is that, the DVR system is not fully IP-based, but a step towards a more advanced IP technology. In fact the DVR system uses the same camera and structures for cabling as older CCTV analog systems, but the DVR is more enhanced in that it convert the data stored into digital data. And the quality of the images captured remains analog since this
is how it originated.
So 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.
