that broadcast a CAG ID contained in the UE's allowed CAG list; the network double checks access attempts against the UE's subscription. Similarly RAN prevents connected mode mobility to non-allowed cells based on enhanced mobility restrictions from the core network. As illustrated in Figure 3.2.14, three types of UE behavior can be distinguished for CAGs: Pre-Release-16 UE or UEs not supporting CAGs ignore CAG cells (UE 1). UEs can be configured to access both specific CAG cells and non-CAG cells, i.e. public cells (UE 2). UEs can be configured to only access specific CAG cells but no public cells (UE 3), e.g. to prevent machines in a factory from connecting to macro cells. PLMN services and Closed Access Group (CAG) services PLMN A System Information System Information Broadcast (SIB) Broadcast (SIB) PLMN ID = A PLMN ID = A CAG ID = X (subscribed for (PLMN A) (subscribed for (subscribed for (PLMN A + CAG X) (PLMN A + CAG X) (subscribed for PLMN A + CAG X; CAG-only) Figure 3.2.14 Closed Access Group (CAG), an enabler for public-network-integrated non-public networks. References It is worth pointing out that CAGs are very similar to Closed Subscriber Groups (CSGs) in EPS (3GPP TS 23.401, 2019), which were introduced in Release-8 and Release-9 to enable femtocell deployments. The key difference is that the CAG concept additionally allows for restricting UEs to CAG cells only (UE3 in Figure 3.2.14). References 3GPP Technical Specification (TS) 03.60 v2.0.0 (1997). General Packet Radio Service (GPRS); Service description; Stage 2. 3GPP. Available at: www.3gpp.org (accessed May 22, 2020). 3GPP Technical Specification (TS) 23.214 v15.5.0(2018). Architecture enhancements for control and user plane separation of EPC nodes. 3GPP. Available at: www.3gpp.org (accessed May 22, 2020). 3GPP Technical Specification (TS) 23.401 v16.3.0 (2019). General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access. 3GPP. Available at: www.3gpp.org (accessed May 22, 2020). 3GPP Te