How Two-Way Radios Work

Analog two-way radios communicate over frequency channels with a bandwidth of 12.5 kHz or 25 kHz. At any given moment on a single frequency, analog radios can only carry one channel.

Digital two-way radios using the NXDN standard communicate over frequency channels with a bandwidth of 6.25 kHz. At any given moment on a single frequency, NXDN radios can only carry one channel.

Digital two-way radios using the DMR standard communicate over frequency channels with a bandwidth of 12.5 kHz, split into 2 time slots of 6.25 kHz each. At any given moment on a single frequency, DMR radios operate on these 2 fixed time slots, giving us 2 parallel communication channels.

DMR Pseudo Trunk / Auto-slot two-way radios: On a Pseudo Trunk system, when a radio transmits, it looks for a free backup slot. If one is available, the radio picks it and places the call. All radios on the system listen on both slots and will only respond to calls intended for their own group.