network and user equipment but also on the practical network deployment constraints. 5G technology alone cannot provide great performance if there is not enough spectrum or enough base stations or if interference is not minimized by coordination. Some of those deployment aspects are discussed in this chapter. Section 8.2 considers spectrum resources, Section 8.3 discusses the density of the existing base station network, Section 8.4 illustrates the usage of mobile data and the asymmetry between the downlink and uplink, Section 8.5 discusses base station site solutions, Section 8.6 describes Electromagnetic Field (EMF) considerations, Section 8.7 presents network synchronization and coordination requirements, Section 8.8 discusses the 5G overlay solution, and Section 8.9 summarizes the chapter. 5G Technology: 3GPP New Radio, First Edition. Edited by Harri Holma, Antti Toskala, and Takehiro Nakamura. © 2020 John Wiley & Sons Ltd. Published 2020 by John Wiley & Sons Ltd. 8 Deployment Aspects 8.2 Spectrum Resources Spectrum is the key resource for any wireless communication. The amount of spectrum defines to a large extent the amount of capacity and the data rates that can be achieved by the mobile operator. If the amount of spectrum is low, it is difficult to provide high capacity and high data rates. The amount of spectrum per operator varies considerably between countries and even within countries. Figure 8.1 illustrates the amount of spectrum per operator in a few example countries. This figure shows the total amount of spectrum downlink and uplink combined between 700 and 2600 MHz in 2019. The total spectrum resources are more than 700 MHz between those frequencies if the entire spectrum is available for the mobile operators. That allows in the best case more than 200 MHz per operator with three operators. We can make a few observations from this figure: There are a few operators having more than 200 MHz spectrum at 700-2600 MHz. The typical amount of spectrum per operator is approximately 150 MHz. The highest a