unicate with each other. The network management can be achieved by a centralized management device or using distributed method or the hybrid approach. Table 5.1 shows the evolution of cellular networks in the past half a century. Compared to the previous generations, 5G network has much higher data bandwidth and has heavily utilized cloud-related technologies in its core network, such that it can better keep up with the demand and resource elasticity. Since this book is related to SDN and NFV's usage in 5G network, in the following, we will focus on the core network of 5G and present how these new technologies can be used in the 5G core network. Among 5 SDN and NFV in 5G Table 5.1 Cellular technology evolution. Mobile network Deployment Data rate 2 kbps 64 kbps 2 Mbps 200 Mbps >1 Gbps Technology Analog Digital Broadband, IP, LAN, CDMA, IP WAN, WLAN Multiplexing Packet Internet Cloud, SDN, network network the use cases, an important one is SFC, which chains multiple network functions together. We will start with the SFC discussion and then fol- lowed by the other use cases in 5G context. Service Function Chaining SFC enables the creation of composite (network) services that consists of an ordered set of service functions (SFs), which must be applied to packets and/or frames selected as a result of classification. SFs are net- work functions responsible for specific treatment of received packets. Today, these SFs are commonly performed by middle boxes. Some typ- ical SFs are network address translation, firewall, malware detection, lawful intercept, load balancing, accounting and policy functions, traf- fic policing, and SO on. In server environments, SFs are virtualized to operate in virtual machines (VMs) or containers. The implementation of a single SF can use a set of virtual or physical machines. Examples of SFC in telecom network are shown in Figure 5.2. Services are constructed as sequences of SFs forming chains. These SFCs are an abstract view of a service that specifies the set of required SFs and the orde