Question: In E-UTRA, when specifying the `supportedBandListEUTRA` for a User Equipment (UE), what does the duplex mode indication signify for each listed band, with respect to TDD (Time Division Duplexing) bands?
Option 1: For TDD bands, it distinguishes between half duplex and full duplex operations, while for FDD (Frequency Division Duplexing) bands, it's irrelevant.
Option 2: The indication is not applicable to TDD bands but mandatory for FDD bands to specify either half or full duplex support.
Option 3: It signifies the UE's preference for either half duplex or full duplex in all band types, including TDD, where full duplex is always preferred.
Option 4: The duplex mode indication is only relevant for bands that support both TDD and FDD, to clarify the UE's operational capability.
Explanation: According to E-UTRA specifications, when listing supported bands in `supportedBandListEUTRA`, the duplex mode (half or full) is indicated for each band. However, for Time Division Duplexing (TDD) bands, this half duplex indication does not apply, as TDD inherently operates on a single frequency band, switching between transmit and receive in time. Thus, the duplex mode indication is particularly relevant for distinguishing operational capabilities in Frequency Division Duplexing (FDD) bands but is not applicable for TDD bands.