ess networks. Some network function (NF) modules and access function (AF) modules are deployed to form an end-to-end network slice with specific service provisioning. NFs and AFs are related to some specific logic functions, such as connection management, mobility management, security, etc., in core network and RAN respectively. Detailed descriptions of the network architecture can be found in [7]. Here we focus on the resource management aspect of the system. From Figure 9.1, we see that slices can share resource in both core and radio access net- works. Specifically, in the core network, the slices using the same link should share link bandwidth resource, computing resource, and NFs. In RAN, the slices deployed in the same AP will share wireless resource as well as AFs. The slice information is broadcast by the APs, and not all NSs will be accessible via every AP. In the example of Figure 9.1, AP 3 broadcasts the information of NS 2 and NS 4, and thus UEs can access NS 2 or NS 4 via AP 3. Focusing on RAN slicing, we consider a multi-slice and multi-AP model shown in Figure 9.2, where the BSs used by multiple slices are deployed in the area (we use BS to Internet : Network function block AF 11AF2|AF4 AF 2|AF 4 AF 3|AF4 : Access function block ((II)) : Network slice information Network slice link Wireless radio link Figure 9.1 Network slice-based network architecture. 9.1 A Framework of User Access Control for RAN Slicing Macro BS Femto Femto : Base station : Network slice Figure 9.2 Multi-slice and multi-AP RAN slicing. denote all kinds of APs throughout this chapter). Each BS can support multiple NSs with different provisioned QoS, and each NS may also be covered by multiple BSs (i.e. each slice information is broadcast by several BSs). Multiple UEs are randomly distributed in this area with different QoS requirements. They can access a specific NS via a BS in the coverage of the NS, thus forming a three layer association relationship. Let B, S, and V denote the set of BSs, NSs, and UEs, respectively. For a spe