Question: In an MBMS Download service announcement session, how are a metadata envelope and its corresponding metadata fragment associated to ensure efficient retrieval?
Option 1: Through separate URIs for each, requiring the download client to request both individually.
Option 2: By embedding the metadata envelope within the metadata fragment file, eliminating the need for separate requests.
Option 3: Using a random association mechanism that pairs envelopes with fragments upon download initiation.
Option 4: Through a grouping mechanism in the FDT Instances, where requesting the metadata fragment URI results in receiving both the fragment and its associated envelope.
Explanation: This is correct because, as per the MBMS protocol for efficient data transfer, the File Delivery Table (FDT) Instances utilize a grouping mechanism. This mechanism allows for the association of a metadata envelope with its corresponding metadata fragment under a single URI for the fragment. When a download client requests this URI (fileURI), both the metadata fragment and its associated envelope are received together, reducing complexity and the number of requests needed.