Meanwhile, the base station can set a plurality of BWPs within one CC configured for the UE. For example, in the PDCCH monitoring slot, a BWP occupying a relatively small frequency domain is set, and the PDSCH indicated by the PDCCH may be scheduled on a larger BWP. And/or, when the UEs are concentrated on a specific BWP, some UEs may be set to switch to other BWPs for load balancing. And/or, some area (that is, spectrum) of the entire bandwidth may be excluded and both BWPs may be set in the same slot in consideration of frequency domain inter-cell interference cancellation between neighboring cells and the like. That is, the base station may configure at least one DL/UL BWP to the UE associated with/related to the wideband CC, and specifically, may activate at least one of DL/UL BWP(s) configured at a specific time (L1) (by signaling, or MAC CE or RRC signaling, etc.). And/or, the base station may instruct the UE to switch to another configured DL/UL BWP (via L1 signaling or MAC CE or RRC signaling, etc.). And/or, based on a timer, a method of setting switching to the configured DL/UL BWP when the value of the corresponding timer expires may also be considered.
In this case, the activated DL/UL BWP may be defined or referred to as an active DL/UL BWP. However, in a situation such as before the UE is in the process of initial access or RRC connection is established (i.e., set up), it may not be possible to receive configuration for DL/UL BWP. In this case, the DL/UL BWP assumed by the UE may be defined or referred to as an initial active DL/UL BWP.