POCSAG is the protocol used for the pager networks.

There are several commercial providers and with DAPNET exists a network for ham radio.

DAPNET https://hampager.de/

The used frequency for DAPNET in Germany is 439.9875 MHz (https://hampager.de/dokuwiki/doku.php?id=dapnetfrq).

Easiest way to use DAPNET is to host a transmitter with a MMDVM HotSpot Board (https://github.com/juribeparada/MMDVM_HS) with PI-Star (http://www.pistar.uk/) on a Raspberry Pi Zero.

If no pager hardware is available a rtl sdr can be used.

Use GQRX as the receiver and forward the POCSAG signal to multimon-ng: nc -l -u -p 7355 | sox -t raw -esigned-integer -b 16 -r 48000 - -esigned-integer -b 16 -r 22050 -t raw - | multimon-ng -t raw -a POCSAG512 -a POCSAG1200 -a POCSAG2400 -f alpha -

This a version which should work without GQRX but is not tested and frequency has to be adjusted to Germany (https://lokcon.me/2019/06/18/rtl-sdr-pocsag) rtl_fm -M fm -f 439.9875M -s 22050 -g 100 -l 310 | multimon-ng -t raw -a POCSAG512 -a POCSAG1200 -a POCSAG2400 /dev/stdin

For test purposes you can send a POCSAG message locally from the pi-star system: sudo RemoteCommand page “” (https://forum.pistar.uk/viewtopic.php?t=746)

https://en.wikipedia.org/wiki/POCSAG

https://de.wikipedia.org/wiki/Radio-paging_code_No._1

https://www.qsl.net/db0avh/code.html - Nachrichtenaufbau von POCSAG

http://www.sxlist.com/techref/pager/pocsag.html - Nachrichtenaufbau von POCSAG