Page 322 - 5G Basics - Core Network Aspects

1 Core network aspects

When an MPC-FE is deployed and supports FSC, the MPC-FE provides the AC-FE with access information as
part of the policy control rules. The access information is used to control the accesses over which the
matching traffic is sent.
When an MPC-FE is not deployed or it is inactive for a multi-connection session, the AC-FE may apply static
FSC related policies. The AC-FE static policy and control functionality is not based on subscription or user
quota information.

For FSC, the MUE and the AC-FE exchange routing rules. Routing rules describe the mapping between a set
of IP flows (identified by a routing filter) and a routing access type (e.g., 3GPP or WLAN types) over which to
route the IP flows. Routing rules are exchanged over the control plane.

The AC-FE translates access information received in policy control rules into routing rules to be used between
the MUE and the AC-FE. In cases where the MUE-initiated FSC is applied (and the policy control entity is
deployed for the multi-connection) the AC-FE provides, upon subscription of the MPC-FE, the MPC-FE with
notifications of the MUE requests for IP flow mapping to an access type. The MPC-FE analyses the received
information (requested IP flow mapping to an access type), makes a policy decision and provides policy
control rules to the AC-FE with corresponding access type values.

The FSC-enhanced related functional entities are shown in Figure 7-1.

Figure 7-1 – Multi-connection flow-based service continuity related functional entities

7.2 Description of the mechanisms

7.2.1 Description of the FSC mechanisms

Following the above-mentioned requirements, two multi-connection FSC modes are supported, the MUE-
initiated FSC mode and the network-initiated mode. The following clauses specify the functional
characteristics of each mode and how they are selected.

7.2.2 MUE-initiated FSC mode
In the MUE-initiated FSC mode, the MUE controls the traffic routing among the multi-connections by applying
its intelligent access selection (IAS) for FSC rules and/or the user-configured routing rules. When the IAS for

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