It depends on your usage. If it is for personal noncommercial usage, 802.11 abgn/ac are within the PTA specified spectrum, and thus allowed under the unlicenced spectrum. Indoor or outdoor uses within personal use are fine. For example, you are allowed to have a really cool wifi setup with multiple APs in your home, providing both indoor and outdoor coverage for you and your family etc.
However, there are some devices which allow far locations to be connected over 802.11 (Point to Point links). These are trespassing in public airwaves and not allowed. If found, these will be removed and confiscated.