GSM

GSM is used to transmit digital alarm signals as a backup to, or to replace, the PSTN Telephone Digital Dialler. A GSM module containing a SIM card is included in or added to a security alarm panel by the Alarm Installer to allow reporting over the GSM Network, normally sharing with mobile phone services supplied by Telco’s.

Where GSM is used it should be realised that on most occasions it shares the network with voice communications which contains many users, a voice priority in demand, a complicated switching between cells, and variance in signal strength. Alarm Data over GSM Networks is sometimes corrupted and messages lost.

GSM over a VPN (Virtual Private Network) has the highest availability and reliability but, it is recommended that the user be aware of the limitations and should not compare the service to the Multipath Service or (Securitel Monitoring even with its Limited availability). It is an alternative to Dialler Monitoring and as a Backup to Dialler Monitoring provides better availability.

Some systems also use the SMS (Short Message Service) path to transmit signals but this should only be used for low priority messages not alarm conditions as SMS is a “Store and Forward” method with no time requirements for message delivery.