Yes, the limitations are due to device certification under part 15. However, this is in no way an implied license, as "license" has specific meaning within the

Yes, the limitations are due to device certification under part 15. However, this is in no way an implied license, as "license" has specific meaning within the context of various parts of the FCC regulations. Part 15 covers unlicensed radiators, so essentially "licensed" and "part 15" are antonyms. This is most significant in that licensing almost always implies some degree of protection from interference (although it may be rather limited), while part 15 devices receive no such protection... when someone interferes with your WiFi, you cannot complain to the FCC (there's some recourse related to the legality of devices, but you cannot for example seek a license modification to address the interference as licensed users generally can to some degree). The existence of "soft licensed" services such as the part 95 services somewhat complicates this as there are services like family radio service (part 95B) that are "licensed by rule," meaning that there is an implicit license, but that somewhat illustrates the point: part 95B radios like the common consumer Motorolas and Midlands are implicitly licensed, WiFi is not! FRS has (limited) regulatory protection from interference, WiFi does not. FRS has limitations on nature of usage, Part 15 has none, but the device must be certified to meet part 15 specs for emissions. The whole "part 15" thing gets more into device certification, which I mentioned in the post I will discuss in the future as it's a topic all of its own. The history of part 15 device certification is closely related to the history of the ISM bands in some ways, but they are not 1:1, as part 15 covers both unintentional/incidental radiators (essentially all electronic devices) as well as intentional radiators which do not have a license... microwave ovens and WiFi are the quintessential examples of the latter. It is of course obvious that RF spectrum belongs to the public, but in the US it is regulated by both the FCC and the NTIA depending on the user and the importance of the ITU cannot be understated as many of these services have at least partial international coordination. Certain radio licenses in the US will also require the approval of either Industry Canada or Mexico's IFT, although this is required under FCC regulations some of which implement treaty obligations. That said, I live in the US and am not a radio technician in the federal government (which is generally exempt from FCC regulations), so I tend to stick to what I know best: 47 CFR! It's also important to understand that in most cases the FCC does not coordinate spectrum usage on a level more granular than services and instead leaves it to other government agencies or private organizations, within the scope of each service. Part 90 is an interesting example, which is FCC licensed on a frequency level but coordinated by private companies for profit (the FCC just approves whatever frequency the private frequency coordinator recommends). I'll probably write on this in the future.