Question: In an MBMS (Multimedia Broadcast/Multicast Service) download using FLUTE protocol, how does a client determine the required symbols to complete a source block when using MBMS FEC scheme?
Option 1: By identifying a minimal set of specific symbols that, combined with already received symbols, allows the MBMS FEC decoder to recover the file.
Option 2: Solely based on the number of encoding symbols in the session description without considering received repair symbols.
Option 3: By calculating the total file size and subtracting the size of all received symbols for that file.
Option 4: Through a manual input by the user specifying missing symbol identifiers.
Explanation: When the MBMS FEC (Forward Error Correction) scheme is utilized, the client must consider already received repair symbols to determine the further symbols needed. This aligns with Option 1, as it accurately describes the process of identifying a minimal set of specific symbols that, when combined with those already received, enables the MBMS FEC decoder to successfully recover the file. This approach optimizes the recovery process by minimizing the additional symbols required.