Cellular back up has been around since late 80's which allows the backing up of a phone line to a Burglar Alarm in case a thief cuts the phone line, trying to keep the signal from going to Monitoring Station. It runs on the side channel of a cellular signal known as side bands Type a and B which allows signals to go thru with out busy and other signals getting in the way since only data not voice is being sent.
Over the years the units have evolved from a large suit cased size unit to a small compact board and now instead of back up there now also being used as the primary way to communicate an alarm since so many homes have no land line or a business is running all VOIP ( Voice Over IP ) instead of traditional dial tone .
How ever almost all units run on AT& T's GSM ( Global System Management ) cellular network while other carriers like Verizon use a technology Known as CDMA ( Code Division Multiple Access ) so if your out a ways from the city you may not be able to get an AT&T signal but a Verizon CDMA signal may be available .
So to bridge this problem UPLINK has produced a cell unit capable of running on CDMA instead of GSM to solve this problem. There a few bucks more to install and they work just as well if not better than the GSM networks .
So your thinking to your self fine, but they sell Cell Phone Jammers illegally which a burglar could use. This is true but because of supervision techniques and fact units run on side band it takes specialized knowledge to stop the signal from being blocked. Which only the most sophisticated burglars have and even if they do jam the signal the burg panels still activate there local sounders which you must deal with and depending on supervision the monitoring center knows your jamming as well. so it is not like you see in the movies. there are even units which attach and use the internet as primary signal and cellular as back up again which is fully supervised no signal and monitoring station starts investigating.
If your home or business is a high risk install for either a Fire or Burglar system due to high ticket life safety value it would be very wise to install a cellular back up unit especially if your using any of the newer digital phone networks which require power from both ends to operate.
Check out up-link cellular service at
Which is available thru your local alarm dealer