23.1393GPP3GPP system - fixed broadband access network interworkingRelease 17Stage 2TS
This clause shows the combined call flow for a handover when a UE moves from an E-UTRAN to an untrusted Fixed Broadband Access network. In addition, the procedures for the IP session establishment for NS-WLAN offload using the Fixed Broadband Access network are also integrated into the combined procedures.
Figure 8.3.5-1: E-UTRAN to untrusted Fixed Broadband Access Handover with DSMIPv6 on s2c
Both the roaming and non-roaming scenarios are depicted in the figure.
If dynamic policy provisioning over S9a is not deployed, the optional steps 5 and 7 do not occur. Instead, the Fixed Broadband Access network may employ local policies.
Handover is only applicable to the EPC-routed PDN connections. For the NS-WLAN offloaded traffic, a new IP session in fixed broadband access network is established.
For connectivity to multiple PDN steps 5 to 6 shall be repeated for each PDN connection.
1-2. This step is the same as steps 1-3 in TS 23 402 , clause 8.4.3, with the following addition: As part of the 3GPP-based authentication, the permanent user identity (IMSI) is provided from the 3GPP AAA Server to the Fixed Broadband Access network
3-4. The description of these steps is the same as for step 2 in Figure 8.3.1-1.
5. This step describes PCC signalling to provision policies for offloaded traffic and is only triggered when the BPCF receives the IMSI and the allocated UE local IP address using Fixed Broadband Access procedures. The description of this step is the same as for steps 3-5 in Figure 8.3.1-1.
6. The description of PDN Connection setup and Gateway Control Session setup are the same as for step 3-5 in Figure 8.3.1-1 with following addition:
– Step 3 in Figure 8.3.1-1 is mandatory when performing handover from E-UTRAN to Fixed Broadband Access.
7. The description of this step is the same as for step 5 in Figure 8.2.1-1
8. The description of this step is the same as for step 11 in TS 23 402 , clause 8.4.3.