the modem state in which there is no data traffic but data scheduling monitoring, synchronization tracking, and mea- surements are needed. In the PDCCH-only state, the modem performs PDCCH blind decoding to moni- tor DL/UL data scheduling, but performs neither DL/UL data decoding nor encoding. The Sleep state comprises two major power consumption contributors: leakage cur- rent on one hand, and paging monitoring and RRM measurement on the other hand. However, only the latter can be improved through better system design and modem implementation. Since there are no field data for a 5G device's DoU power consumption, only the phone's power consumption in a downlink data session (for sub-6-GHz) running at peak rate can be analyzed, as shown in Figure 13.12. The figure shows that the proportion of the modem's power consumption ranges from 70% to 80% of the total estimated power consumption of the device, depending on the number of component carriers. This num- ber is not expected to go down much in a typical DoU and will likely be significantly greater than 20% for an LTE phone. Unless special measures are taken in the system design to lower the power consumption when the modem is not actually processing its data, the user experience in 5G may be worse than 4G. The reasons are mainly twofold. First, the 5G NR modem is very efficient at high peak rates since it consumes much less energy per bit compared to LTE due to LDPC code, as mentioned in Section 13.2.1. Therefore, operation at non-peak rates does not lower the peak power consumption much. Second, the primary source of power consumption in a modem is its RF circuits' current drain, which scales with the bandwidth. With 5G NR carriers typically having a much wider bandwidth (100 MHz for sub-6-GHz) than LTE, the standby state power consumption in the modem would be much higher than in LTE if the RF circuits were always tuned to the widest bandwidth. The situation would be even more severe in the mmW spectrum where the carrier bandwidth is upward of 400 MHz. Based on