dPMR

dPMR is a DMR system from China which uses a several chinese Codecs instead of the DVSI AMBE codecs commonly used by other digital systems.  These radios are cheaper as they do not need to pay license fees for the Codecs. Practically you have to use radios from the same manufacturer on both ends of the communication, as they are not much standardized.

 

dPMR Functional Levels

dPMR Mode 1: A general purpose peer to peer application of dPMR for all forms of licensed PMR use. Mode 1 is part of the ETSI standard TS102 658.

dPMR Mode 2: A licensed PMR version that includes all base station and repeater functionality. Mode 2 is part of the ETSI standard TS102 658.

About dPMR technology

Both the FDMA (Frequency Divided Multiple Access) radio protocol employed in dPMR and the other widely adopted protocol, TDMA (Time Divided Multiple Access), deliver a 6.25kHz narrowband channel capability. The key difference between the two protocols is that the FDMA protocol presents ‘true, always double capacity’ 6.25kHz  narrowband spectrum efficiency rather than the ‘equivalent’ 6.25kHz  narrowband achieved by TDMA through creating two 6.25kHz equivalent channels from a 12.5kHz channel when a repeater is used to synchronize the time slots.

dPMR radios employ industry standard DVSI AMBE+2™ vocoders which converts an analogue audio signal to a digital signal while reducing unwanted interference such as background noise and acoustic echo to provide better voice quality and clarity.

Digital modulation protects dPMR radios from being easily monitored by an analogue receiver and an inbuilt 15-bit digital scrambler adds further to the resulting enhanced security.