Radio network system is created to work autonomously within security company’s network, therefore ensuring full communication control and increased security. Radio alarm messages are sent via Contact ID protocol. This means that transmitted information is as detailed as using GSM network. Messages are transmitted to ARC directly or via repeaters depending on a distance and an environmental interference between a transmitter and a receiver. Depending on requirements different encoding systems can be used such as RAS-3, RAS-2M, LARS, LARS-1 and Milcol-D.