DIPRA® DMR Radio Networks 
Digital Mobile Radio (DMR) as specified by the European Telecommunication Standards Institute (ETSI) was first published in 2006. The Technical Specifications TS 102 361-1 to TS 102 361-4 altogether describe the DMR Air Interface, whereas the Technical Report TR 102 398 outlines the general system design of DMR. The latter provides an overview, a description of the DMR services and facilities, technical background and radio aspects, protocol and service performance, and guidance on numbering and addressing.
DMR is specified in two categories, meaning to different degrees of complexity:
- Tier II, a 2-way radio specification with mobile terminals and repeaters operating in licensed spectrum,
- Tier III, a trunked radio specification with mobile terminals and trunked radio networks operating in licensed spectrum.
Both DMR tiers comprise a 2-slot TDMA (Time Division Multiple Access) air interface in radio channels of 12.5kHz bandwidth, i.e. its effective bandwidth per channel is 6.25kHz as an excellent prerequisite for the strong demand of today towards spectrum efficiency. DMR is meant to be operated in the general PMR bands, i.e. in the frequency ranges between 30 and 1000MHz.
RADIODATA as one of the leading PMR companies in Germany has developed its DIPRA® - Digital Professional Radio system - based on the ETSI Specification of DMR, with all subsystems as components available to deploy a PMR network:
- DIPRA® switch SW2400, including voice transcoder, web-based network management and a Simple Network Management (SNMP) agent to interface to an external network management system,
- DIPRA® DMR basestation BS2400, as single channel or multi channel in standard or simulcast version,
- DIPRA® DMR mobile radio terminals and DMR data modems, MS22xyD and DM22xyD, respectively.
