Question: What is the primary purpose of utilizing the Private Message mechanism in the UTRAN Iub interface Node B Application Part (NBAP) signalling?
Option 1: To ensure multi-vendor interoperability for all network features.
Option 2: For standardizing new algorithms before their implementation.
Option 3: For operator- and/or vendor-specific features not part of the basic functionality, including research on new algorithms/features prior to standardization proposal.
Option 4: To replace standardized signalling for basic network operations.
Explanation: The Private Message mechanism is designed for non-standard uses, such as implementing operator- or vendor-specific features not part of the basic functionality. This includes using it for research purposes to test new algorithms or features before standardization proposal, without impacting standardized, multi-vendor interoperable aspects.