Revision as of 12:29, 14 August 2024 edit Graeme Bartlett (talk \| contribs) Administrators 258,980 edits m radioamplifier fix ← Previous edit		Revision as of 15:12, 2 September 2024 edit undo IlliterateSage (talk \| contribs) 134 edits Removed the part about DAPNET's frequency being at the top of the band. While it's true for the ITU allocation, many countries (e.g., the United States) has a larger allocation, up to 450 MHz. I also added a bit about hotspots, as that's another way to use DAPNET. Next edit →
Line 1: [[File:DAPNET-logo.png\|thumb\|right\|DAPNET logo]] '''DAPNET''' (Decentralised Amateur Paging Network) is a free global paging network created and maintained by [[amateur radio]] enthusiasts. Messages can be received on commercially available [[pager]]s that support the [[POCSAG]] protocol and are tuned to the appropriate [[Radio frequency\|frequency]]. [[File:Ham-pager.jpg\|thumb\|right\|DAPNET as of July 2023]] ==History== A similar ham radio project called FunkrufMaster was quite popular around 2000. It was based on [[AX.25]]-technology and the former Packet Radio Network. Because of the upcoming HAMNET- and [[Internet Protocol\|IP-Protocol]] era, a successor was needed. Members of the ham radio activity group at [[RWTH Aachen University]] designed and developed '''DAPNET''' from scratch as a modern software approach. <ref>[https://www.ralfwilke.com/index.php/en/about-me Ralf Wilke - About]</ref> As of March 2018, over 90 transmitters were already in permanent operation, and the coverage area included parts of [[Germany]], the [[Netherlands]], [[Belgium]], and [[Switzerland]].<ref>[https://hampager.de/dokuwiki/doku.php?id=dapnetoverview DAPNET Overview]</ref>, with [[Raspberry Pi]]-based personal hotspots extending coverage around the world<ref>[https://hampager.de/dokuwiki/doku.php?id=mmdvm]</ref>. ==Technical specifications== The recommended frequency for DAPNET is 439.9875 ~MHz,<ref>[https://hampager.de/dokuwiki/doku.php?id=dapnetfrq Recommended frequencies]</ref> which is ~~12.5 kHz below the upper limit~~part of the [[70-cmcentimeter band]] dedicated to amateur radio ~~band~~use. 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 use [[Raspberry Pi]] with unipager<ref>[https://github.com/rwth-afu/UniPager Github: UniPager]</ref> and MMDVM-modem<ref>[https://www.researchgate.net/publication/312934460_Development_of_a_Decentralized_Paging_Transmitter_Network Development of a Decentralized Paging Transmitter Network]</ref> installed, and to make the coverage area several miles, a radio amplifier needs to be added to its output.<ref>[https://hampager.de/dokuwiki/doku.php?id=raspager RasPager - Simple low-power Transmitter]</ref> The coverage area of the transmitter can be up to 1220 ~~miles~~km (2012 kmmiles), depending on the terrain and the height of the antenna. ==Receivers== Skyper and ~~Alphapoc~~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 or [[Flipper Zero]] can be used. Messages can be sent via a multilingual website as well as [[Android (operating system)\|Android]] and [[iOS]] apps.

DAPNET: Difference between revisions