Question: What type of antenna interface techniques are allowed in the NG-RAN architecture for controlling RET antennas or TMAs?
Option 1: Only proprietary techniques
Option 2: Only standardized techniques from a single vendor
Option 3: Both standardized and proprietary techniques, but with restrictions on standardized techniques
Option 4: Any standardized antenna interface technique, including AISG specifications
Explanation: The NG-RAN architecture allows for the support of any standardized antenna interface technique, including those from the Antenna Interface Standards Group (AISG), without preventing their use. This ensures flexibility and interoperability in the control of RET antennas or TMAs.