RE: [802.21] Interface of MIH with Upper layers
In 802.11 the SAPs are normative. There are no indications that they are informative, so by default they're normative. However, they are not referenced in the PICS so they are not mandatory.
In reality it would not be possible to construct an API that was identical to the SAPs - the lack of context handles is just one example. In addition, practical implementations often differ from the reference model for reasons of performance.
The reason for having SAPs in 802.11 is not to provide interoperability. It's because you can't specify the behaviour of the MAC without some concept of what is inside the MAC, and what's outside.
Mike.