FreqTel-PTT is a state-of-the-art Push To Talk service based on ROIP technology. Relying on the GSM signal, our radios are able to talk to each other without any range restriction. Each radio works with a SIM card  and uses GSM/3G/4G and some models even work with a WiFi signal. This means that you don’t need to spend a fortune on expensive radio infra-structures, like repeaters, antennas, or leasing sites. All the network infra-structure is provided by the GSM carrier.