All configuration takes place over environment variables. Here are the defaults:
FREERUN=true
RUNTIME= # n/a; this is parsed into a time.Duration
STATION_COUNT=2000
BANDS=160m:0.75,80m:0.85,40m:0.95,20m:1.0,10m:0.9,6m:0.8,2m:0.7
MODES=FT8:1.0,FT4:0.5,CW:0.5
TRANSMISSION_PROBABILITY=0.65
STICKINESS=0.999
REPORTER_ADDRESS=localhost:4739
If FREERUN is false, and RUNTIME (e.g., "900s") is supplied, the program will run for the specified time.
Otherwise the run will continue until terminated.
STATION_COUNT is the total number of stations. Memory consumption increases quadratically with more stations, as it's,
in the name of runtime performance, necessary to precompute the distances from each station to every other station.
BANDS gives a relative weight for each, so that with the default setting above, it's four times more likely that a
station transmits on the 20-meter band, than on the 160-meter band, for example. The default also lists the bands that
the system currently understands. MODES follows the same pattern. Note however that the weights for bands and modes
get multiplied together.
TRANSMISSION_PROBABILITY represents the likelihood of a station transmitting during a given slot.
STICKINESS represents the likelihood of a station to stick to the band and mode it's currently working.
The service exposes the following metric on port 9108/tcp:
hamtraffic_station_transmissions_total{band=~"[0-9]*m", mode=~"(CW|FT4|FT8)", callsign=~"X0.*"}
hamtraffic_station_receptions_total{band=~"[0-9]*m", mode=~"(CW|FT4|FT8)", callsign=~"X0.*"}
hamtraffic_network_report_packets_total{network=~"(tcp|udp)", remote=~".*:[0-9]*"}
The last one increases with every packet sent towards whatever is receiving the reports.
As there can be many callsigns, cardinality can get high. I wouldn't be that concerned though, as this is a testing
tool that isn't supposed to be running around the clock. There's a Docker composition in this repo's root, which runs
the hamtraffic service, plus Prometheus and Grafana. Grafana can be accessed at localhost:3000, and includes a basic
overview dashboard; the dashboard ("hamtraffic") can be found by browsing under "General".
To make it less likely to facepalm and get things mixed up with real hams, all callsigns are generated with prefix X0,
which as of 2023-02-17 isn't allocated.
The prefix is followed by a suffix of four letters from AAAA to PPPP. This range will provide around 65.5k unique
callsigns, which should be enough for this purpose at this time.
To make the generated data feel less synthetic, stations get their locations from around 7.5k cities around the world. The following query was run in overpass turbo to get a GeoJSON file listing all cities in OpenStreetMap data:
[out:json];
(
node[place="city"];
);
out body;
>;
out skel qt;
It is a mystery to me why the query language looks like that (see here for a more complex example), but I'm sure there are valid reasons.
The definition of what is considered a "city" seems to vary quite a bit in the data, currently the smallest one (Hmawbi) has a population of 17. But anyway, that doesn't matter because the aim is to spread the stations around the world in an "organic" pattern. Which doesn't mean that the station's locations would reflect in any way how amateur radio operators are spread around the world, just that in those places there are (at least some) people. The main reason for taking this approach is that I didn't want to deal with (massive) geography data to differentiate between land and water, for example. Relatedly, maritime mobile isn't considered at all, yet.