Alarms ? wired or wireless

[bernardgreen]

It is a pity that every time this question is asked personalities rise up into conflict and the answer to a valid question is lost in personal attacks.

All burglar alarms can be comprised to the point they are no longer effective as a burglar alarm. The amount of skill, ability, equipment and time needed to render an alarm ineffective will vary depending on the quality of the alarm system's design and installation.

In all attacks on an alarm system ( other than destroying the external siren box before it can make a noise ) it is necessary to intercept one or more of the communication links between modules of the system ( sensor, keypads, control box, sirens, bell boxes ) and create false signals of "no intruder detected" or block signals of " intrusion detected ". Or create false dis-arm signals to turn the system off.

With a wired system the attacker has to get access to the wiring to intercept the signals between modules. This means in almost all cases the attacker has to gain entry at some time to the building to be able to work on the wiring.

With a wireless system access to the building is not necessary to intercept the signals between modules. They can be intercepted and falsified from a location as far as a hundred yards from the protected premises.

Many wireless systems have jamming detection, very few have jamming avoidance.

Jamming detection will only provide at most an alarm indication that the system has been compromised by jamming. While this is happening the system is un-likely to be able to respond correctly to a intruder entering the premises.

Some wireless systems do not have jamming detection and these systems can be completely inhibited by jamming without giving any indication that the premises are no longer protected.

Jamming avoidance will provide an indication that jamming is occuring and at the same time re-configure its radio communications to avoid the jamming source. This invariably requires a change of radio frequency in all modules to a frequency that is not being jammed. This makes all modules complex, expensive and the use of additional frequencies is not permitted by the "licence free" use of radio communications in domestic burglar alarm systems.

 

[Europlex]

Jamming detection will only provide at most an alarm indication that the system has been compromised by jamming. While this is happening the system is un-likely to be able to respond correctly to a intruder entering the premises.

Some wireless systems do not have jamming detection and these systems can be completely inhibited by jamming without giving any indication that the premises are no longer protected.

From one of the 'personalities'

Thanks for the above, couple of paragraphs, they totally vindicate all the comments from the 'personalities' don't they?

Who in the DiY market (end user) would know the difference between DiY Radio systems Jamming Detection and the more professional Jamming Avoidance systems, care to name one?

Fit a wired system from an Approved company with all the backup that is included - The END


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[Atilla]

wireless has failed - ask yourself this simple question .........
if you had to save someones life and both were available would you use your mobile or your house phone?

 

[olbas]

In our house, more chance with the mobile. Teenage daughters always on main phone and all deny ever having seen it when you want to use it.

Yep, a wireless phone. Same as most people use.

 

[olbas]

Don't think he said that.

But in the context of alarms, there's diy toot and then there is the more robust, Graded products.
We're looking at the new Grade 3 wireless kit at the moment.

 

[Atilla]

We're looking at the new Grade 3 wireless kit at the moment.

which one?

 

[olbas]

which one?

GSD

 

[Atilla]

and thats grade3 - how`d they manage that then?

 

[Atilla]

They used a team of experts from their burb.

Looks quite contemporary equipment , stylish I would be interested to know more.

down to the two way comms but whisper this quietly - the grading commitee aren`t convinced. Hopefully google alert will get a GSD chap over here to explain.

 

[olbas]

The guys behind it have a history of development within the industry - no, that's not taken from any marketing blurb.
There appears to be a certain amount of misinformation being put about.
I've heard of one Inspector who is completely wrong in his understanding of it.
Also, can't see them rushing on here any day soon. Not the market they're aiming for.

 

[olbas]

Wind your neck in.

GSD are fully aware of the comments and they're sources - and no, as much as you try and suggest, it isn't Atilla. Why? i myself informed them about them. In this instance, it is the grading committee who need to be careful.

It would seem you are not well versed in the industry as you struggle to differentiate between an Installer and a Manufacturer. How can they be a competitor?

For the record, it is a neat bit of kit with many useful features, but NOT aimed at the boxshifting diy end of the market. For anyone struggling to grasp why or how, the clue is in the Grade.

 

[Atilla]

I can name you a half a dozen products that are / were brought to market with the wrong grading applied - but thats the problem with self regulation.

Would be nice to get some manf. input on this.

 

[drgl]

now that is libel - LOL, you silly boy

Well YOU certainly are grade 1.............

"MD of a medium to large NSI gold approved firm"

I can't think why you constantly bash wireless DIY kit (on a DIY FORUM) and advise people to get a pro in, vested interest per chance? This site SUCKS these days in a BIG way, mods/admin kindly delete my account, i no longer wish to be part of a community that puts up with this constant BS.

 

[olbas]

No you ain't.

 

[bernardgreen]

I am just seeking clarification from someone who claims to know it all.

This could be the truth. But I am only going to talk about one link.

A well designed system depending on a radio link as the only communication to bell box or siren that is powered only by batteries.

The control unit sends a test message to the bell box. This test message includes a unique address for the box. This prevents another box on a near by house being affected. The box replies to confirm it has received the test message. The reply includes a unique reply code for the box. This confirms to the control panel that the correct box has replied.

To improve the security a random number can be included in the test message and the box then calculates a reply number to include in the reply. Each box would compute a different reply to the same number. If the control panel does not get the correct calculated number in the reply then the panel can assume the box is not in order or an attempt to replicate the box is being made.

What happens if the panel does not get a reply from the box ? It can create a local to the panel alarm. It can also send a " start the bell " signal to the box.

But if the box does not reply because its battery was flat there is no way to sound the alarm outside the property. If the bell box did not reply because there was a jamming signal when the test message was sent that prevented the bell box receiving the message then, if the jamming signal is still there, the message to sound the bell will have no effect.

What to do then, if the bell box detects jamming and / or misses a routine test call the only thing it can do is set it's bell ringing. It can try to inform the control panel but the panel could be dead or jamming is still present. To be sure of alerting to the problem the box has to sound the alarm. This is a false alarm as no intrusion has occurred ( other than an intrusion into the communications of the alarm system if jamming is present ).

How many such false alarms can occur before the battery in the bell box is flattened making the bell box un-able to operate when a real alarm is needed.

Perhaps a compromise is possible, wire-less connected sensors and hard wire connection to the bell box. But there are still problems with radio links to and from sensors.