ext step will be gradual refarming from LTE to 5G. The refarming from LTE to 5G can utilize Dynamic Spectrum Sharing (DSS), where both 8.2 Spectrum Resources Example operator spectrum resources at 700-2600 MHz Figure 8.1 Typical operator spectrum resources at 700-2600 MHz downlink + uplink combined (APAC = Asia Pacific, NAM = North America, MEA = Middle East Africa, LAM = Latin America). Figure 8.2 Typical spectrum strategy for Before 2020 and sub-6-GHz bands. 2019/20 beyond 3G+LTE 2G+LTE LTE/5G 2G+3G 2G+3G LTE/5G LTE and 5G control signals occupy the full channel, and the resource allocation can be done in a dynamic way in the time domain depending on the instantaneous device dis- tribution and service requirements. DSS uses close coordination between LTE eNodeB and 5G gNodeB packet schedulers for jointly optimizing the resource allocations. DSS can make the refarming to 5G a smoother process compared to earlier technologies. DSS is discussed in Chapter 10. 8 Deployment Aspects Spectrum Base station Network capacity resources density potential Figure 8.3 Network capacity potential defined by amount of spectrum and base station density. Base stations per 10k population Figure 8.4 Base station density in different countries. Network Density The maximum achievable network capacity is defined by the spectrum resources and by the network density. Even if spectrum resources are great, the network capacity remains low if the network density is low. This basic principle is shown in Figure 8.3. Network density refers here to the number of base stations compared to the population. There are major differences between countries. Figure 8.4 illustrates the approximate macro network densities in terms of base stations per 10 000 persons. The calculation includes the combined number of base stations of all operators divided by the country's popu- lation. The highest network densities are found in the Nordic countries, and in Japan, Korea, and China. The medium network densities can be found in the European and North American n