DoIP: A Parallel Protocol Conversion Gateway for DMR over Internet Protocol

Digital Mobile Radio (DMR) is widely used in mission-critical communication due to its cost-effectiveness. However DMR only provide voice service for users in a small range. To address these limitations, a protocol conversion gateway named DoIP was designed and implemented to allow DMR devices to access a variety of communication services over long distances using the internet. In our proposed hierarchical model, DoIP works in an add-on mode. To meet the requirements of real-time, reliable, and multimedia applications, we designed the DMR frame structure, SPI packet structure, and Internet Protocol (IP) packet structure for inter-layer transmission. We also proposed the mapping rules between different protocols and achieved the conversion of DMR frames to IP packets. Finally, we implemented the DoIP on a commodity DMR repeater and evaluated its performance. The comprehensive evaluation revealed that DoIP successfully realized protocol conversion between DMR and TCP/IP, with a conversion delay of 9.10 ms, a packet loss rate of 0.3%, and an average jitter of 1.90 ms.