2.2 Overall RAN Subsystem The RAN subsystem, i.e. the RAN part of network slice, holds the following features: A service device accesses the Third Generation Partnership Project (3GPP) network via a RAN subsystem as if it were connected to the service provider's network. The RAN subsystem is characterized by service-specific network topology, protocol con- figuration, connection control, and mobility management. The key incentive is to allow operators to provide tailored solutions to vertical service providers over the same network infrastructure [1, 8]. An example is given in Figure 12.2. More specifically: For devices supporting factory automation slice, which is a combination of mMTC and URLLC, they would treat their accessed RAN subsystem as a factory automation "private" network with subsystem2. The low latency, high reliability, and even the deterministic data transmission would be through this "private" network. For cars supporting V2X slice, which is a combination of eMBB and URLLC, they may access the V2X "private" network to have both high-quality video service and (11[1)) Router Common platform to deliver branded services Subsystem1 Subsystem2 Subsystem3 Subsystem4 Figure 12.2 RAN subsystem branding. 12.2 General Concept and Principles fully automated driving. Different tenants used for different car companies may be treated with different RAN subsystems for different subsystems such as subsystem3 and subsystem4. Those sensors supporting metering slice, a kind of mMTC service, in the number of mil- lions, can perceive to be accessing their own "private" network with subsystem1. These low-cost devices characterized by low burst data rate, long battery life, and large coverage requirements communicate via their own RAN subsystem network [9]. 12.2.3 Key Principles of Network Slicing in RAN In this section, the general principles related to the realization of network slicing in the next generation radio access network (NG-RAN) for new radio (NR) are given. The support of network slicing relies on the princ