Why your phone line is giving your alarm fits

You look at your alarm one day and see a trouble light, in checking the trouble you see failure to communicate. What is going on with this system? Lets start with how your alarm talks to the monitoring center. Your alarm has a modem in it like you would have in a computer from the 1980’s, anyone remember Prodigy? Back when the modern dialer started to replace the tape dialers of the past (more on that in a future post) it transmitted over a copper wire to your monitoring center going through switching centers controlled by the telephone company. This was an analog signal transmitted through a very robust system.

Then along came government deregulation of the telephone industry which allowed new players, like cable companies, to enter the market. These new players needed a way to make providing phone service profitable for them at a lower cost than the traditional telephone providers. The way they did this was by using VoIP or Voice over Internet Protocol. What VoIP does is take the analog signal and convert it to digital then compress it to send it over the internet. This is why you need a device, like a cable modem, to connect to the phone service. On the other end of the system the signal is uncompressed and converted back to analog for use.

To digress for a moment. The way to think of a analog signal is to think of waves on a ocean. By varying the size or the distance between the waves you create patterns that can be changed to sound. Digital audio is a series of 1 and 0’s that could be though of as long and short pulses. A computer can decode these pulses and convert them into an analog wave used to produce sound in a speaker for example.

The problem occurs during this compression, conversion to digital, uncompression, conversion to analog cycle. What can happen is the dialer signal can get slightly out of sync from how it started out. The modems in your alarm panel and at the monitoring center then can not recognize each other. The result is that either your alarm thinks that it did not transmit to the monitoring center and it will continue to call the center over and over, or the center will not think that your alarm is a valid alarm for that center and will hang up on your alarm resulting in the alarm not getting through. In either case the VoIP phone service has been the weak link resulting in your alarm not alerting someone in your time of need.

How do we prevent phone problems from defeating our alarm system? In the 21st century the standard is now to have the alarm report in via cellular radio. This is a small radio that is similar to a cell phone that is used by the alarm to transmit to the monitoring center. This radio takes the VoIP modem out of the picture in transmitting to the center. Cellular radios have other advantages. They are almost always powered by the alarm panel so they are battery backed up like the alarm, if you system has battery backup. They allow for smart phone control of your system through third party services, such as alarm.com. They can’t be cut like a hardwired phone line can. Finally, if you are keeping a phone line just for the alarm, they save you money by eliminating the need for a phone line.

If your alarm is still on a phone line give Waves a call at 248-652-2809 or email us info@waveslowvoltage.com for a no obligation quote to upgrade your system.