n the reference direction) or the The transmitter transient period is the time interval during which the transmitter is changing from the trans- mitter OFF period to the transmitter ON period or vice versa in a TDD base station [5]. 672 Chapter 5 minSENS RoAoA [the reference Range of Angles of Arrival (RoAoA) associated with the OTA sensitivity direction declaration (OSDD) with the lowest declared EIS] as appropriate for the receiver. The radiated transmit power is defined as the EIRP level for a declared beam at a specific beam peak direction. For each beam the requirement is based on declaration of a beam identity, reference beam direction pair, beam-width, rated beam EIRP, OTA peak direc- tions set, the beam direction pairs at the maximum steering directions, and their associated rated beam EIRP and beam-width(s). For a declared beam and beam direction pair the rated beam EIRP level is the maximum power that the BS is declared to radiate at the associated beam peak direction during the transmitter ON period. For each beam peak direction associ- ated with a beam direction pair within the OTA peak direction set, a specific rated beam EIRP level may be claimed. Any claimed value must be met within the accuracy require- ments. The rated beam EIRP is only required to be declared for the beam direction pairs [5]. The TRP and EIRP metrics are related through the number of radiating antennas and are implementation specific, considering the geometry of the antenna array and the correlation between unwanted emission signals from different antenna ports. An EIRP limit results in different levels of total radiated unwanted emission power depending on the implementa- tion. The EIRP limit per se cannot control the total amount of interference in the network, whereas a TRP requirement limits the total amount of interference in the network regardless of the specific BS implementation. In the case of passive systems, the antenna gain does not noticeably vary between the desired signal and the unwanted emissions. Thus EIRP is d