Currently AT&T is weakening the 2G network signal used to monitor alarm
transmissions, as they will be switching to the 4G network by the year 2016. The Alarm
Company, Inc. is seeing dropped cellular signals on the 2G network already. Your
security system has a 2G-GSM AT&T cellular radio installed and you will be affected by
this change.
Source: Security System New http://www.securitysystemsnews.com/taxonomy/term/4101