In 2008, in an effort to reduce the number of false alarms that they were responding to,  An Garda Síochána introduced a garda alarm policy  to clarify which type of alarm activations they will respond to. The policy is clear – only verified alarms will qualify for Garda cover. A verified alarm is one in which two sequential detection devices have activated in a premises.

For example, an alarm could be classified as a verified alarm if the alarm panel sends information to an ARC showing two sequential devices activating (an example would be where it is shown that someone has triggered the front window followed by a PIR beam in the hallway).

In a situation where only a single zone activates (e.g. the front window only) the Garda will not attend the premises (as it is more than likely a false alarm).
What is the relevance of this for alarm monitoring purposes?
This policy means that a signal fault (e.g. dropped GSM/GPRS signal from an alarm transmission system, or a dropped telephone line ) or a single zone activation (e.g. a front window only activating) will not qualify for Garda response.
In a situation where GSM/GPRS jammers are used at a premises the only indicator within the Alarm Receiving Centre (ARC) of an issue will be missed polls or basically no network coverage. No signal from any of the detection devices of any kind inside the premises will be received by the ARC as the cellular network used to send these signals will be blocked.