AT&T Security Systems
AT&T's origins date back to the late 1800s. Rooted in telegraphic communications, the company is known for their reliable network that allows America to stay connected. Owners and operators of one of the most reliable modern cellular networks, AT&T provides phone service for a large portion of the nation. Cellular data is not only used for phone calls, however. While phone calls are the primary use for these networks, Alarm Grid makes use of AT&T's cellular network with its communicators that use their network to send signals.
AT&T security systems use either the 4G LTE or 3G network, depending on the communicator and system. This does not affect the performance of either of the systems. Both networks are adequate for the reliable transmission of alarm signals. Additionally, end users can decide whether to use a system with the addition of a WIFI or IP communicator which will provide redundancy of communication. While using the AT&T cellular network is the most reliable way for your system to communicate, having redundancy via an IP connection will make the communication all the more reliable.
For those with poor AT&T cellular coverage in their area can also select between Verizon CDMA, or Movistar or Rogers, if you're in Mexico or Canada respectively.
This is true for Honeywell's security products as well as any of the other major brands of security systems. The 2GIG, DSC, and Interlogix alarm panels are all capable of working on any of these numerous networks.