DAPNET (Decentralised Amateur Paging Network) is a free global paging network created and maintained byamateur radio enthusiasts. Messages can be received on commercially availablepagers that support thePOCSAG protocol and are tuned to the appropriatefrequency.

A similar ham radio project called FunkrufMaster was quite popular around 2000. It was based onAX.25-technology and the former Packet Radio Network. Because of the upcoming HAMNET- andIP-Protocol era, a successor was needed. Members of the ham radio activity group atRWTH Aachen University designed and developedDAPNET from scratch as a modern software approach.^[1] As of March 2018, over 90 transmitters were already in permanent operation, and the coverage area included parts ofGermany, theNetherlands,Belgium, andSwitzerland,^[2] withRaspberry Pi-based personal hotspots extending coverage around the world.^[3]

The recommended frequency for DAPNET is 439.9875 MHz,^[4] which is part of the70-centimeter band dedicated to amateur radio use. The transmitters are networked, some via HAMNET, some via the Internet. The standard paging protocolPOCSAG is used for message transmission. For a low-power transmitter you can useRaspberry Pi with unipager^[5] and MMDVM-modem^[6] installed, and to make the coverage area several miles, a radio amplifier needs to be added to its output.^[7] The coverage area of the transmitter can be up to 20 km (12 miles), depending on the terrain and the height of the antenna.

Skyper and AlphaPOC pagers are particularly popular for receiving messages. They can be easily tuned to the desired reception frequency and also offer many other possibilities, such as receiving bulletins - messages sent to all recipients. However, other brands of pagers can be customized accordingly orFlipper Zero can be used.

Messages can be sent via a multilingual website as well asAndroid andiOS apps.

• hampager.de

• Radio paging
• Digital amateur radio