 fiber). The 3.2 5G Core Network (R)AN Figure 3.2.4 5GC user-plane configuration with concurrent access to a local and central data network using a single PDU session. key motivation for this was to enable integrated operators who offer both fixed and mobile services to harmonize their core network infrastructure to reduce Capital Expenditure and Operational Expenditure. When looking into the details of WLAN ANs or wirelines networks (e.g. as defined by Broadband Forum), it becomes clear that some system aspects will continue to be access specific, for example, security, mobility handling, or QoS enforcement. Therefore, to achieve the goal of a common core network despite this, 3GPP decided to hide AN specifics from 5GC inside access network-specific adapter functions, e.g. the Non-3GPP Interworking Function (N3IWF) for WLAN or the Wireline Access Gateway Function (W-AGF) for wireline ANs as depicted in Figures 3.2.5 and 3.2.6, respectively; define common control- and user-plane interfaces between the core network and ANs that apply to both 3GPP accesses (E-UTRA and NR) as well as to the adapter functions for non-3GPP accesses, i.e. N3IWF and W-AGF.4 Access N3IWF Data Network HPLMN Non-3GPP Networks Untrusted Non- 3GPP Access Figure 3.2.5 N3IWF hides specifics of non-3GPP access networks (e.g. WLAN) from 5GC. (Source: reproduced with permission from © 3GPP). 4 In practice, even though the interfaces are largely common, there are still some access-specific messages and information elements. 3 5G System Overview Access Data Network 5G-RG W-AGF W-5GAN Figure 3.2.6 W-AGF hides specifics of wireline access networks from 5GC. (Source: reproduced with permission from © 3GPP). While this approach may come across as merely shifting complexity from one part of the system to another, it has two salient benefits: The same control- and user-plane architecture (AMF, SMF, UPF with common interfaces toward other functions like PCF, UDM, etc.) applies to all accesses. In contrast to this, EPS is based on different architectures f