4.2.3 Roaming Architectures for EPS

23.4023GPPArchitecture enhancements for non-3GPP accessesRelease 18TS

Figure 4.2.3-1: Roaming Architecture for EPS using S8, S2a– S2b – Home Routed

Figure 4.2.3-2: Roaming Architecture for EPS using PMIP-based S8, S2a, S2b (Chained PMIP-based S8-S2a/b) – Home Routed

** Chained S2a/S2b and S8 used when VPLMN has business relationship with Non-3GPP Networks and S‑GW in VPLMN includes local non-3GPP Anchor.

NOTE 1: AAA, mobility, and QoS policy and event reporting related optimizations (e.g. signalling reduction and information hiding towards the HPLMN) for PMIP-based S8-S2a/b chaining are not specified within this Release of the specification.

NOTE 2: GTP-based S8-S2b chaining is not specified within this Release of the specification.

The following are some additional considerations in this case:

– Gxc is used only in the case of PMIP-based S8 and for 3GPP access.

NOTE 3: If QoS enforcement on PMIP-based S8 is required by the Serving Gateway for Un-trusted Non-3GPP IP Accesses, static policies will be used in this Release of the specification.

– Gxc is not required for Trusted Non-3GPP IP Access; Gxa is used instead to signal the QoS policy and event reporting.

NOTE 4: For S2a using a Trusted WLAN access, refer to clause 16.

Figure 4.2.3-3: Roaming Architecture for EPS using S8 – S2c – Home Routed

Figure 4.2.3-4: Roaming Architecture for EPS using S5, S2a, S2b – Local Breakout

NOTE 5: The two Rx instances in Figure 4.2.3-4 apply to different application functions in the HPLMN and VPLMN.

NOTE 6: For S2a using a Trusted WLAN access, refer to clause 16.

Figure 4.2.3-5: Roaming Architecture for EPS using S5, S2c – Local Breakout

NOTE 7: The two Rx instances in Figure 4.2.3-5 apply to different application functions in the HPLMN and VPLMN.