Forgive me if this is not the proper forum, but I am an electrical engineer and a total radio novice.
I am designing a product that may contain off-the-shelf industrial radios that act as repeater devices. I recently spoke with an engineer at an industrial radio manufacturer, and he said that "almost certainly" a license is required if I am planning to use a 900 MHz repeater, even if I had intended for the rest of the system to be 900 ISM/unlicensed.
Can anyone confirm or deny this? I cannot find anything definitive, but I am probably not googling with the right terminology.
(I am in the United States, but I am working on a device that may be sold in the EU and/or Australia.)