Page 484 - 5G Basics - Core Network Aspects

1 Core network aspects

• following handover, encapsulate user packets received from the UE (at the tunnel lower end in the
case of network-based mobility) or from correspondent nodes (at the tunnel upper end) and
forward them through the tunnel; similarly, decapsulate packets received from the tunnel and
forward them to the UE (at the tunnel lower end in the case of network-based mobility) or to the
correspondent node (at the tunnel upper end).

6.5 Reference points

Figure 3 shows the functions and functional entities described above along with the functional blocks and
entities already defined in [ITU-T Y.2012]. The links between the functions indicate required information
flows, identified by reference points M1 through M13. M1 through M8 and M13 are between MMCF entities
and other entities. M9 through M12 are flows between entities of the MMCF. The set of links shown in
Figure 3 is the superset of the links shown for individual scenarios in clause 7.

MMCF
MLM-FE M9
NACF RACF
M1 M10
HGWC-FE M8
M2 HDC-FE PD-FE
M11
TUP-FE TLM-FE
M13 NID-FE
TAA-FE NAC-FE
M12
TRC-FE
AM-FE NIR-FE

M3
M7
M4
UE M5
Control plane
M6 Forwarding plane

AR-FE
L2HE-FE EN-FE ABG-FE IBG-FE
L2 transport Packet transport
AN-FE L3HEF L3HEF L3HEF
functions functions
Access transport Core transport Y.2018(09)_F03

Figure 3 – Reference points and information flows involved
in mobility management and control
6.5.1 Reference point M1 between TLM-FE and MLM-FE(P)

This information flow is used to distribute several types of information from the TLM-FE to the MLM-FE(P).
The TLM-FE is assumed to be able to contact the NAC-FE via an internal reference point to obtain the
persistent and temporary IP addresses (see clause 8.1.2 of [ITU-T Y.2014]).

6.5.1.1 Indication of host-based mobility
In the host-based mobility case, the information transferred includes the keying material derived from the
UE authentication procedure (see clause 7.3.2), in support of the security association required between the
MLM-FE(P) and the UE. The information passed from the TLM-FE to the MLM-FE(P) may also include:

• mobility service user ID;
• persistent IP address of the user;
• binding between mobile user ID and persistent IP address.

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