seded by the TX spurious emissions requirements. For RX-only multi-band con- nectors, the spurious emissions requirements are subject to exclusion zones in each sup- ported operating band. For multi-band connectors which transmit and receive in operating band supporting TDD mode, the RX spurious emissions requirements are ver- ified during the TX OFF period and are subject to exclusion zones in each supported operating band. The number of active receiver units that are considered when calculat- ing the conducted RX spurious emission limits (NRXU-counted) for BS Type 1-H is given as NRXU-counted = min(NRXU-active> 8Ncells) where NRXU-counted-per-cell is used for scaling of basic limits and is derived as NRXU-counted-per-cel = NRXU-counted/Neells where Ncells was defined earlier. The NRXU-active is the number of active receiver units and is inde- pendent of the declaration of Ncells. Since the receiver emissions are dominated by the transmitted signal, the receiver spurious emission limits are only applicable when the transmitter is not active, and also when the transmitter is active for an NR base station operating in FDD mode that has a separate receiver antenna connector [5]. 5.3 UE Transceiver RF Characteristics and Requirements 5.3.1 General UE RF Requirements An NR UE should support both standalone and non-standalone operational modes. For the non-standalone operation, the LTE carrier(s) is required to be the anchor carrier for the NR UEs. In addition to LTE and NR, there may be operators around the globe which rely on 3G and other 2G services. Those radio access technologies may utilize different 692 Chapter 5 frequency bands/channels for operation. The discrete (non-integrated) RF front-end archi- tectures that support these RATs and their associated frequency bands may provide good RF performance; however, there would be implications related to cost, form factor, and hardware complexity. Multi-mode multi-band integrated RF architectures may overcome many of the challenges of the discrete design. Such archi