Question: What is a requirement for a User Equipment (UE) that supports uplink Licensed Assisted Access (LAA) operation in terms of simultaneous transmission?
Option 1: Simultaneous transmission of PUCCH in licensed spectrum and PUSCH in LAA Secondary Cells (SCells) must be supported.
Option 2: Simultaneous reception of PDCCH in licensed spectrum and PDSCH in LAA SCells is mandatory, but not for uplink.
Option 3: The UE can choose between transmitting either PUCCH in licensed spectrum or PUSCH in LAA SCells at any given time.
Option 4: This capability is only required if the UE also supports downlink LAA operation.
Explanation: According to specifications, UEs supporting uplink LAA operations must support simultaneous transmission of Physical Uplink Control Channel (PUCCH) in licensed spectrum and Physical Uplink Shared Channel (PUSCH) in Licensed Assisted Access (LAA) Secondary Cells (SCells), ensuring efficient utilization of both licensed and unlicensed spectra.