Premises Security (part 12) Summary

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Premises Security (part 12) Summary

So the sensors are chosen, the cameras are installed. The recording system has been chosen. Power has been assured for an acceptable length of time.
Let's do a final summary:

Part 1 discussed the different types of security systems.

Part 2 explained the differences between Local and Monitored alarms and Perimeter vs. State-change detection along with a look at some different video security surveillance cameras.

Part 3 looked at wireless vs. wired security systems.

Part 4 looked at setting up a video security installation.
Part 5 covered remote monitoring of the video installation and security risks associated with that. It also considered using Motion Detection.
Part 6 Began an overview of NON-video surveillance devices.
It covered;
The “closed loop”, Micro/Magnetic Reed/Thermatic & Pressure Mat switches
Part 7 Continued the overview of NON-video surveillance devices.
It covered detection of environment change rather than physical switch operation
It considered;
Pulsed Infra-red beams, Passive Infra-red (PIR) movement detectors, Proximity detection
Part 8 Completed the overview of NON-video surveillance devices.
We considered that security is more than just Intruder Detection so then looked at Temperature and Light/Darkness security sensors such as;
Thermal Fuses, Thermistor or semiconductor temperature monitors, LDR or Semiconductor light sensors.
Part 9 Considered the two points raised in Part #1 of this series.

The first point was the trade-off of cost & size vs functionality, risk and aesthetics. That led into the discussion in Parts #2 thru #8, of the various types of security system and the devices used.

The second point was the possibility of having the "best of both" in a small easily installed surveillance system AND
extended power coverage by use of a "UPS" as a power backup.
Parts #10 & #11 talked about battery life, working out run-time calculations and the different types of UPS. It also touched on power quality and preferred brands of UPS.

So that wraps up a very high-level view of premises security using digital video surveillance.
I will gladly discuss any specific questions which this series of articles may have either left untouched or perhaps stimulated.

In my next post, I'll start to look at some of the forgotten aspects of security of computer data, caused by corruption, theft or malicious intrusion by virus or hacking.

Premises security (part 3) Wired or Wireless ?

Last installment we looked at a couple of different cameras which can be installed to give fairly good picture quality.

One thing I forgot to mention was that the light-handling ability of some of the cheaper cameras is VERY poor.
I have returned several indoor cameras because they simply wash-out the scene when it becomes brightly lit - such as in full sunshine.
The moral here is to check before destroying the packaging !

Today I want to look at the first of the topics you should consider if you've decided to give Do-It-Yourself surveillance a go.
This topic is Should I Use Wireless or Wired security?

First of all, it needs to be said that no matter what type of system you install, they are all susceptible to intentional disruption.

There are a number of wireless based home security systems on the market.
Most reputable wireless units have jamming detection built into them, which will dial a monitoring service if radio-based interference is detected.
One I have personally found to be quite adequate for my purposes on small security installations, is the LYNX security system from ADEMCO.

Differences between the two types
The major differences between a wired and a wireless installation are that the sensors all need regular battery maintenance and that intrusion can be effected without having to actually enter the premises.

Obviously wireless installations lend themselves to difficult sites and also for speed and ease of installation. On the other hand the cost of the sensors is greater as too are battery maintenance costs.

Wired installations are conversely more difficult to interfere with because physical access is necessary. They also support cheaper sensors, although this can easily be offset by the cabling costs.
Wired installations also have the benefit of a central power source rather than having to maintain relatively expensive long-life batteries (often Nickel Metal Hydride) in a dozen different and often difficult-to-access places.

Special considerations for video installations
Where video surveillance is concerned, there are some additional issues which need to be considered.
The cameras still need a power source so they are NOT truly wire-less!

Because the publicly available wireless cameras operate on a public radio channel shared by many other devices and users, general non-malicious interference can cause such severe signal degradation as to render the image(s) useless. Also, because the signal is usually NOT encrypted, anyone within 100m can view what is being "seen" by the cameras.

Take care what the camera "sees"
This latter point may not be so bad in outside settings where no pattern of traffic is obvious nor anything of value visible. Within a building however, to monitor your heirlooms cabinet or your $10,000 home theatre equipment is rather like putting signs out within 100m of your premises to advertise what you have that's worth stealing!
Another thing that is forgotten when using wireless monitoring, is that your patterns of movement can be very accurately recorded so thieves know when you are likely to not be in a room or building.

Image Quality and Distance to Cameras
Picture quality and reliability is significantly superior with a cabled video system but does have distance limitations without signal repeaters.
Image quality is often more "noisy" with radio and also has distance limitations which are harder to overcome than with cable extenders.
My own experience with wireless cameras has shown that while 100m is possible with clear line-of-sight between the camera and the receiver, ANY obstacle will drastically degrade the distance/quality of transmission

Next installment I'll start talking about monitoring the devices and how they may connect.

If there is anything you disagree with me on, or want clarification about, please feel free to add comments