The New Threat to Alarm Signalling

By Paul Tattersall

Vee-PLEX Reporter

Since the early 2000’s the signalling of alarm activations has moved steadily away from the tried and tested digital communicators and into the area of GSM, the mobile phone technology.

This has been true for both the Remote Monitoring Centres and for the self-monitoring, where the subscriber gets a text or voice message in the case of an alarm activation.  This has worked fine up to recently providing relatively  cheap, efficient and reliable communication of alarm information.

However, something dramatic has changed recently.

It has now become apparent over the past year or so that the existing GSM products have a serious flaw. They can easily be jammed.

The so-called ‘jammers’, electronic devices currently little bigger than a hand-held walkie-talkie, are readily available over the internet from China.  A year to eighteen months ago the Gardai started picking up criminals having these devices in their possession and it was soon realised that they were spreading throughout the country. Discussions with Garda Crime Prevention officers from Cork to Monaghan reveal that they are turning up in all corners of the country.

Gangs were using them to target firstly industrial estates, where the jammers blocked outgoing GSM alarm signals, then more recently, it was realised that Dublin-based gangs were driving down the country and  targeting housing estates in provincial towns. They park outside vulnerable houses, switch on the jammers, which are laid on the back window of the car and are plugged into the cigarette lighter socket,  then break into several homes in the area. This has become widespread, and one Garda who recently arrested a well-known burglar  found a newly delivered jammer from China in his house, together with the invoice for $65. It has now become an epidemic,  and even though a recent law has outlawed the possession of these devices the criminal world has taken steps to circumvent this by hiring out jammers  by the night, just as they do with guns.

So well-known burglars need not worry about their home being raided by Gardai, as no jammer will be found!

The mobile phone jammer has many quite legitimate uses ; they have been used in cinemas to prevent calls disrupting viewers enjoyment of films, and several priests have used them to prevent phones ringing during church services. Prisons similarly use them to prevent inmates from using smuggled  phones to direct their affairs on the outside.

Many people have a common misunderstand about the technology of the jammers and think that they actually ‘ jam ‘ or block the frequency of the mobile phone signal. This is not true. The jammer actually mimics the identity of a typical GSM receiving cell. The mobile phone cells are about 5 miles apart, which is how the location of a mobile phone can be so easily tracked. When one makes a mobile phone call the phone automatically searches for the strongest signal, which will naturally come from the nearest cell or mast location, and it will latch onto this cell and put through the call. In the case of a jammer, the strongest signal will be coming from the device sitting on the back window of a car parked outside your gate, which will naturally induce the phone to direct its call to this location, from where, of course, the message goes nowhere.

Typical jammers generally have a range of about 100 metres, however it is rumoured that the Gardai recently seized a unit from a Dublin criminal which had the power to block all mobile phone communications throughout Dublin City.  It is also alleged,  by people in the know, that just before Christmas 2014 Customs at Dublin Airport opened an incoming box and found it to contain no less than a hundred jammers. But how many other such shipments had got through?

So the jammers are now widespread, presenting a major problem for the security industry.  For example, how do you explain to an irate customer who calls up his alarm company the morning after he has been burgled and says his alarm never got the signal out?  Was it just a technical fault in the dialler, overcrowding on the network, or was there a jammer parked in his road?

The Gardai are naturally very worried by this development since literally hundreds of thousands of alarm systems are using GSM technology, and all these installations are now vulnerable. There is currently a big rush on from manufacturers to provide an answer to this problem.

A number of solutions are currently being suggested, from going back to the old landline, to using a ‘heartbeat’  system with the GSM to monitor its functioning, or using Broadband as the signalling medium. Some systems use dual signalling in the hope that one will get through. However,  using two vulnerable technologies, e.g.,  landline and GSM together,  is only marginally better than using one, since all the burglars have to do is cut the phone line at the terminal box outside the house, as criminals have been doing since the 1970’s ; cut the phone line,  switch on the jammer and Bobs yer uncle!

Broadband is a more secure technology since it cannot be jammed, but many broadband routers, apart from wi-fi ones, operate over the telephone line which, once again, can easily be cut. Consequently for a broadband dialler to be effective the connectivity must be Monitored and notifications of disconnection reported rapidly, either to the customer or to the Monitoring Centre, or both.

Amazingly, some installers are reverting to the  voice dialler, which many will remember was pioneered by Kestral during the 1980’s. This is very low level security, but cheap, and if you are on the phone when the call comes, or in a meeting or in bed or in church, etc., with the phone switched off or on silent, or in an area of poor network reception…. need I go on? You get nothing.

There are solutions and installers should be thinking carefully about which to use, but doing nothing is not an option because the jamming situation is not only very real but widespread, and people will be victimised – people who put their trust in their security company to protect them. So, be honest, be brave and discuss all the options and costs with your customer and help him/her decide on the best solution; that way you are covered if they opt for a technology which is subsequently compromised.

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