n Processor (AP). This generic architecture may vary slightly depending on the operating radio fre- quency of the modem. An optional 4G baseband and mixed signal unit (dotted lines in Figure 13.1) may also be present in a multi-mode device. Multi-mode support is, as for all of the past gen- erations, essential to ensure a smooth migration to the newer generation and thereby provide continuity of service in areas where the newer generation is yet to be deployed. In the early phase of the migration, this 4G unit is likely to share part of the RF unit with the 5G modem. For cost reduction, it is necessary that the overall modem architec- ture also continues evolving at later stages with a higher degree of integration and hard- ware sharing among all supported radio access technologies, whether cellular or other wireless connectivity. The baseband processing unit comprises a number of hardware modules, one or more general-purpose Digital Signal Processing (DSP) cores, an internal high speed memory unit, and a control processor. The hardware modules are bespoke functions for computationally intensive tasks such as channel coding, cell search, and Radio Resource Management (RRM) measurement. Together with the DSP core that performs general-purpose computation, they account for the bulk of the modem's computa- tional complexity that delivers NR's multi-Gbps data rates. The control processor is responsible for scheduling the various modules and coordinating their communications between each other through the internal memory for each procedure in the NR protocol stack. This control flow complexity is, compared to Long Term Evolution (LTE), much higher, due to 5G NR's in-built flexibility and configurability as well as its much more stringent latency requirement. The cumulative computational, control, and architectural complexity naturally lead to yet another great implementation challenge; that of mitigating power consumption. NR introduces a number of features to keep these issues in check. Most notable of all is the Ban