DAPNET

DAPNET logo

DAPNET(Decentralised Amateur Paging Network) is a free global paging network created and maintained byamateur radioenthusiasts. Messages can be received on commercially availablepagersthat support thePOCSAGprotocol and tuned to the appropriatefrequency.

DAPNET as of July 2023

History

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-Protocolera, a successor was needed. Members of the ham radio activity group atRWTH Aachen Universitydesigned and developedDAPNETfrom scratch as a modern software approach.As of March 2018, over 90 transmitters were already in permanent operation, and the coverage area included parts ofGermany,theNetherlands,Belgium,andSwitzerland.

Technical specifications

The recommended frequency for DAPNET is 439.9875 MHz,which is 12.5 kHz below the upper limit of the 70-cm amateur radio band. The transmitters are networked, some via HAMNET, some via the Internet. The standard paging protocol POCSAG is used for message transmission. For a low-power transmitter you can useRaspberry Piwith unipagerand MMDVM-modeminstalled, and to make the coverage area several miles, you need to add a radioamplifier to its output.The coverage area of the transmitter can be up to 12 miles (20 km), 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 Zerocan be used.

Messages can be sent via a multilingual website as well asAndroidandiOSapps.

External links

• hampager.de