Question: Which of the following UE types are NOT supported over Non-Terrestrial Networks (NTN) in the current specification release, assuming they lack GNSS capability?
Option 1: UEs with enhanced coverage capabilities
Option 2: NB-IoT UEs
Option 3: BL (Broadband Low-complexity) UEs
Option 4: All UE types supporting only TDD (Time Division Duplexing) systems
Explanation: According to the specification, NTN is only applicable to FDD (Frequency Division Duplexing) systems in this release. Therefore, any UE type that only supports TDD systems would not be supported over NTN, regardless of its other capabilities. The other options are incorrect because BL UEs, UEs with enhanced coverage, and NB-IoT UEs (with GNSS capability) are explicitly mentioned as being supported over NTN in the current specification release.