Dynamic Spectrum Sharing enable 4G and 5G networks to share RF bandwidth SO to gradu- ally transition spectrum usage as consumer equipment upgrades take place. Low-band spectrum dedicated to IoT use cases is also under consideration, reusing tradi- tional television bands for 3GPP operation, given that television services are moving to digi- tal/IP-based. Examples include 3GPP-approved frequency bands in 400 MHz frequency range, driving harmonization of chipsets/devices and networking equipment: Band 87, 10 Open Radio Access Network (O-RAN) Systems Architecture and Design 410-415 MHz uplink and 420-425 MHz downlink, and band 88, 412-417 MHz uplink and 422-427 MHz downlink. The largest amount of spectrum freed for licensed (operator) 3GPP use is in the mmWave bands, 24-26 GHz (China, EU); 28 GHz (Japan, Korea, United States); and 39 GHz (China, United States). These wide (GHz + ) bands provide the promised step function in capacity but come with technology standards through poor propagation characteristics that force deployment of much smaller cell sizes, overlay networks, and other nontraditional deploy- ments. Later in this chapter, we will discuss what these nontraditional form factors can look like and how they force the industry to rethink implementations along the lines of O-RAN standards and concepts. Licensed private spectrum Deployment of private networks requires availability of spectrum to deploy the network on. In fact, spectrum availability typically defines the deployment format. There is no harmonized spec- trum for private networks across the globe. By implication, equipment choice, RF regulation, and cost will end up varying by region. Government harmonization efforts are under way but are not expected to solve this challenge in the short-term future. We look at three examples: United States, Germany, and Japan. United States In the United States, the FCC is opening 150 MHz of "CBRS" spectrum in the 3.5 GHz (3550-3700 MHz) band as shown in Fig. 1-5. This spectrum is intended for use by three tiers