Topic: DMR (Digital Mobile Radio)
When: Feb 16th, 2023 7:30pm
Background: DMR is used on the amateur radio VHF and UHF bands, started by DMR-MARC around 2010. The FCC officially approved the use of DMR by amateurs in 2014. In amateur spaces, Coordinated DMR Identification Numbers are assigned and managed by RadioID Inc. Their coordinated database can be uploaded to DMR radios in order to display the name, call sign, and location of other operators. Internet-linked systems such as DMR-MARC, FreeSTAR (an experimental multi mode network which has connections with numerous digital & analogue systems), BrandMeister network, TGIF, DV Scotland – Phoenix UK (the two networks merged in late 2022), FreeDMR and several others (including several previously closed clusters which now connect to larger networks to wide area accessibility), allow users to communicate with other users around the world via connected repeaters, or DMR “hotspots” often based on the Raspberry Pi single-board computer. There are currently more than 4,000 repeaters and 15,000 “hotspots” linked to the BrandMeister system worldwide. The low-cost and increasing availability of internet-linked systems have led to a rise in DMR use on the amateur radio bands. The development of Raspberry Pi-based hotspots, often those using the Pi-Star software, has allowed users to connect their radios to one or more internet-linked systems at the same time. DMR hotspots are often based on the open source Multimode Digital Voice Modem, or MMDVM, hardware with firmware developed by Jonathan Naylor.