Page 287 - 5G Basics - Core Network Aspects

Core network aspects 1

Based on the operator's strategy, the MCF assists the UE in discovering available access networks by providing
the following information to the requesting UE.

Inter-system mobility policies (ISMP):
1) access priority: e.g., if a specific radio access technology (RAT) and/or access network identifier is
preferable;

2) restriction: e.g., if the inter-system mobility is restricted;
3) validity conditions: e.g., conditions indicating when the provided access network discovery
information is valid.

7.2.2 Terminal-based access discovery solution

Figure 7-3 – Terminal-based access discovery

In the scenario of terminal-based access discovery, as shown in Figure 7-3, when selecting an AP, a terminal
is required to perform an access network request, which includes supported providers, capabilities of the AP,
etc. The AP would respond to the terminal with a list of items that specifically describe the available services,
which include the capabilities of the networks being accessed, authentication types required by or available
with the AP, etc.
After receiving the related information, the terminal would compare provisioned profile information against
the data from the AP, confirm the accessible list of roaming providers, and finally associate itself with the
best SSID to authenticate identity. All processes are completed in an automatic way.

7.3 Access selection solution
7.3.1 Network-based access selection solution

Many operators deploy Wi-Fi to offload cellular network traffic. Hence, access discovery selection is a crucial
function to be supported. The policy for selection should make optimal use of the available access
technologies. The solution should consider how terminals discover and select access technologies using
policies from their home operator. As to the network aspect, it is easier to acknowledge the coverage of each
access, to collect access status dynamically and to schedule the radio resources by time and user class.
1) provisioning: Once the UE is connected to the network by any access, the network policy would be
pushed to the UE by the MCF as the reply to the UE’s registration request. See Figure 7-4 below.

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