Page 517 - 5G Basics - Core Network Aspects

Core network aspects 1

Access network Core network

HSS

hPCRF
Rx
S6a Home Gx
S9
PDN SGi Operator's
gateway IP services
(IMS, etc.)

S10

MME S8 vPCRF
S1-MME
S3 S11 Gxc
S1-U Serving
E-UTRAN gateway

S4 Visited
2G/3G
SGSN
Y2018(09)_FIII.2

Figure III.2 – Roaming architecture for 3GPP accesses
within EPS using PMIP-based S8

The mapping of functional components in this case is the same as in the non-roaming case, with the exception
that the visited network policy and charging rules function (vPCRF) must now be considered. Aside from its
relay function, the vPCRF is really a source of policy for connection to the backbone network lying between
the visited public land mobile network (VPLMN) and home public land mobile network (HPLMN).

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