To allow the UE to distinguish RSs from different carriers, the FRBs should be different for different carriers, although the FC could be the same. Hence, the FC being part of the reportConfig still allows the FRB to be associated with the MO, and be possibly configured explicitly or implicitly. For example, there can be a one-to-one mapping between a set of allowed FRBs per carrier frequency. The set is given since there can be multiple FCs. Hence, for a given measId linking a MO and a reportConfig, the UE knows the FC for that measId and the MO. Thanks to the MO the UE knows the exact FRB for that provided FC. Alternatively, the UE is provided with the FRB in the MO explicitly.

If the same FRB is used for different MO's (e.g., for different carrier frequencies), the UE cannot distinguish the cells from different carriers.

Examples for Providing FC and/or FRB Information

For UEs in RRC Connected state, the information about FC and/or FRB can be provided as part of the measurement configuration (measConfig) which can be provided in an RRC Connection Reconfiguration, an RRC Connection Resume or an RRC Connection setup. The information may also be provided via system information (broadcasted or UE specific or upon a request or upon a determined need, etc.) and some common parts of the information may also be provided via broadcasted system information. For UEs in RRC Inactive state or RRC Idle, the information about FC and/or FRB can be provided via system information, which can either be broadcast or requested on demand