NXDN™ and dPMR
NXDN is a different protocol also based on 4FSK FDMA for 6.25kHz. For further details you are invited to visit their Forum

dPMR is a digital radio protocol specifically targeting highly functional solutions by using low cost and low complexity technology.

dPMR is a narrowband (6,25 kHz) FDMA technology that is 100% digital that offers many forms of voice and/or data applications. More >>