You’re pretty close. Yes water absorption and therefore microwave ovens, but it also means that 2.4GHz is a terrible frequency to use for commercial radio. Leaves are full of water, as are clouds, and rain, which means long range propagation generally sucks. So it was reserved legally for Industrial, Scientific, and Medical uses, and it’s mostly a free for all with regards to transmission and interference.
You’re also correct that the band being unlicensed led to wide adoption in short range consumer radios due to lower costs. There is still compliance testing, but it’s done for things like the right to use the official WiFi logo, not to appease the FCC.
You’re pretty close. Yes water absorption and therefore microwave ovens, but it also means that 2.4GHz is a terrible frequency to use for commercial radio. Leaves are full of water, as are clouds, and rain, which means long range propagation generally sucks. So it was reserved legally for Industrial, Scientific, and Medical uses, and it’s mostly a free for all with regards to transmission and interference.
You’re also correct that the band being unlicensed led to wide adoption in short range consumer radios due to lower costs. There is still compliance testing, but it’s done for things like the right to use the official WiFi logo, not to appease the FCC.