erefore, controlling intra-cell RoT is less of a concern than managing inter-cell interference and maintaining adequate link quality. In this respect, LTE power control aims at controlling the UE transmit power spectral density to meet the eNodeB target sensitivity level for a given MCS and PRB allocation. Second, UE either transmits control information on PUCCH or data on PUSCH, but never simultaneously. Since PUCCH transmissions occur on a single PRB, at low bit rate and high coding gain, each physical channel is controlled by a completely independent loop, resulting in two independent UE transmit power PDFs. The situation is further complicated by sounding reference signals (SRS) transmissions which typically occur in the last symbol of a 1 ms sub-frame. There- fore, mapping UE transmit PDF to UE power consumption is more difficult in LTE than in WCDMA. Figure 16.43 shows examples of PUCCH, PUSCH and SRS transmission power profiles collected in a 2x2 MIMO, AWS band, 20 MHz cell bandwidth LTE network. 2 The smartphone runs radio/music streaming during the whole duration of the drive route. A detailed analysis of each profile can be done by retrieving from the drive logs both open-loop and closed-loop power control parameters. This analysis goes beyond the scope of this section. For this music streaming application, PUSCH and, to a greater extent, SRS transmissions, occur less often than PUCCH transmissions. This can be clearly seen in both PDF and power versus SFN graphs. This is expected as uplink traffic is small compared to downlink (Figure 16.42b). In this example, PUSCH average transmit power is approximately 18 dB higher than that of PUCCH. Extracting the open-loop Po nominal parameters from SIB2 and RRC connection setup messages for PUSCH and PUCCH explains that this power offset cannot be less than 14 dB in this network: Po_PUSCH is set to - 106 dBm, Po_PUCCH to 120 dBm and alpha 1.0. See Chapter 11 for more details about the power control parameters. Establishing Empirical Relationship Between RSRP and