The Weak Signal Propagation Reporter Network is a group of amateur radio operators using a digital mode developed byK1JT (Nobel price winner Joe Taylor) to probe radio frequency propagation conditions using very low power (QRP/QRPp) transmissions.
Occasionally I put my station "probing" the conditions during idle times. This afternoon I put it to work on 14,0956 MHz for a couple of hours. These ( at most a few watt, even milliwatts are used) WSPR nodes were found during that time.
Note the distances that milliwatts can achieve with a clever digital communication mode. The important assets in WSPR are a) very slow bit rates b) exact clock synchronizations.