Similiar to lolamby' regular post on his free software contribution, I want to start a similiar post.
The big chunk of the December I prepared together with the GSM team the celluar network at the 36c3 (36. Chaos Communication Congress). Every year we're building our own celluar network using free software project osmocom & open5gs. Osmocom is a community project around mobile communication. We used osmocom to run our core network (CN) of our 2G and 3G network. Open5gs is our LTE CN, which was interconnected to the osmocom CN. Here is a overview, every buble is an own daemon.
The 36c3 was a nice testing ground. We had to extend a couple of the services (e.g. osmomsc, osmogsup2dia, osmohnbgw). While the event we also like to enjoy the congress, so this is our excuse to not upstream our patches right a away. However we push our branches as it is to https://git.osmocom.org. Upstreaming will be more seen in January.