arge difference would indicate limited beam steering capabilities as a result of, for example, a limited number of panels, beam granularity, constraints on the panel location, and constraints on the steering angles for each panel. BC is the ability of the UE to select a suitable beam for UL transmission based on DL measurements with or without relying on UL beam sweeping. BC ensures that every Tx beam has an identical corresponding Rx beam. The core requirements for BC are particularly difficult to define as many uncertainties in the UE mmWave antenna panel may introduce errors depending on the mmWave transceiver architecture. For example, the impact of phase shifter errors and PA/LNA gain errors are some examples the numerous ongoing discussions [11], For the receiver chain effective isotropic sensitivity (EIS), SC was added to ensure that sensitivity performance can be measured using all directions surrounding the UE, not just one panel at a time. For the PC3 UE, the EIS SC is defined similarly to the EIRP SC, as the 50%-tile CCDF of the EIS measured over the full sphere around the UE. All requirements are applicable to each antenna panel, and are verified with the UE beam locked into the beam peak direction. They must be tested in extreme temperature conditions (ETCs), that is, versus temperature, battery voltage, and across all channel bandwidths (50, 100, 200, and 400 MHz), some at 60 kHz SCS, others at 120 kHz, and for Table 12.6 Power class 3 UE maximum transmit power OTA KPIs summary. Min EIRP at 50%-tile CDF (dBm), i.e. Min peak EIRP Operating spherical (dBm), i.e. at coverage 100%-tile CDF 12 5G RF Design Challenges each supported band, the UE must be tested at ow-mid-high channels. One can easily picture that adding OTA uncertainties and limitations would only add to the overall legacy "conducted" test complexity. 12.4.4 Transmitter Aspects 12.4.4.1 Power and Device Classes As discussed in Section 12.4.3, in FR2, most UE KPIs are defined with radiated perfor- mances. For this reason, the UE power class