The digital technology has revolutionized the data transfer in many areas of our life. Also in radio communication this trend does not stop.

How does digital radio communication work?
The analog voice signal is converted into a digital signal with a vocoder (voice encoder/decoder). The transmitter converts the analog signal into a digital one and the receiver reverses this process. Due to the characteristics of digital technology, the signal is less prone to interferences than an analog signal. Damaged signals can be easily restored by adding the missing parts. Nevertheless, it is important to mention that the area coverage of an analog and a digital signal is the same. 
Interfaces to computer networks are easily accessible and the signal transport around the globe is all of a sudden possible.
Encryption of digital signals is more advanced and guarantees a private conversation.

The availability of different digital radio communication protocols, e.g. FDMA or TDMA, causes issues with the compatibility between different vocoders, e.g. AMBE+ or ASLEP. Therefore, it is important to check that different radios of different manufacurers use the same vocoder is they are part of the same network.  

The differences between analog and digital signals in an overview:

  • Digital signals are less prone to interferences than analog signals.
  • The typical analog channel noise is missing with digital signals.
  • Toward the borders of the area coverage, analog signals get increasingly weak until they fade out, i.e. they are not understandable any more. Digital signals remains steady and strong until they are cut off. Digital technology does not increase the coverage area but provides a steady signal quality.

Due to the compatibility issues between different vocoders and the hesitant implemenation of digital radios, we decided to offer a combined analog/digital dPMR radio. This allows to substitute older analog models in concurrent networks and, at the same time, set up new digital networks for the transition.  

Regarding the selection of the vocoder, we based our decision on the aspects of popularity and costs. For the future, all digital TEAM radios should be compatible with each other to make a smooth transition from analog to digital networks possible.