In digital radio, the analog voice signal is converted into a digital signal with the help of a so-called vocoder (voice encoder / decoder), i.e. it is encoded by the transmitter and decoded by the receiver. The digitally converted signal is not only less susceptible to interference, but also more versatile in terms of the data format, e.g. when transmitting text and images. The integration into computer-controlled networks is possible and previously unimaginable ranges are possible through the use of the Internet. It is worth mentioning the quality of the voice encryption which, compared to scramblers in analog radios, actually encrypts the signal incomprehensibly.
The use of different radio protocols, e.g. FDMA or TDMA, as well as different vocoders, such as AMBE + or ASELP, brings about compatibility differences. Within a digital radio network, all devices must be equipped with the same vocoder.
The digitization of data transmission has established itself in many areas. This technology is also spreading in radio communication. A complete switch to digital radio communication is not to be expected in the foreseeable future, but it is worth following this development.
Digital radio is less prone to interference than analog radio. When transmitting frequency-modulated signals (FM), interference radiation can change the signal considerably. This is not the case with digital radio. The frequency noise typical of analog radio is missing in digital radio. As long as the signal strength is sufficient, the signal is clearly audible with digital radio without any interference. The digital transmission breaks off in the limit areas of the signal range. In the case of analog transmission, you can still hear the signal, even if you can no longer understand it. Digital radio does not increase the range compared to analog transmission but the signal quality.
Against the background of the existing compatibility problems and the slow spread of the digital registration and fee-free dPMR-446 radio, as well as the company radio, we have decided to include combined analog-digital radio devices in our program. This makes it possible to set up a new digital network without giving up the connection to analog devices.
In selecting the vocoder to be used, we prioritized the criteria of popularity and cost. All digital TEAM devices of the future should be compatible with each other and thus be able to be integrated into existing TEAM device networks without any problems.
Combined analog-digital devices enable them to be integrated into existing analog networks and at the same time to set up a new digital network. The devices are available in the versions dPMR-446 (registration and fee-free) and dPMR-COM (registration and fee-based company radio).
