This clause specifies the support of Hybrid Access considering both the support of PDU session and MA PDU session.
Hybrid Access applies to a 5G-RG capable of connecting to both NG-RAN and to W-5GAN. Hybrid Access also applies to a 5G-RG capable of connecting to W-5GAN/5GC and E-UTRAN/EPC using EPC interworking architecture. Hybrid Access does not apply to FN-RG.
The following Hybrid Access scenarios are supported with single-access PDU sessions:
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Hybrid Access using PDU session carried only on a single access, either NG-RAN or W-5GAN, but that cannot be simultaneously on both accesses. Such PDU Session can be handed over between NG-RAN and W-5GAN using procedures described in clause 4.9.2 of TS 23.502, but with UE replaced by 5G-RG and N3IWF replaced by W-5GAN.
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Hybrid Access using single access connectivity for 5G-RG supporting LTE/EPC and EPC interworking. In that case mobility between W-5GAN/5GS and E-UTRAN/EPC is handled using interworking procedures described in clause 4.11.3 of TS 23.502, but with UE replaced by 5G-RG and N3IWF replaced by W-5GAN.
The following Hybrid Access scenarios are supported with multi-access connectivity:
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Hybrid Access with Multi-Access PDU Session connectivity over NG-RAN and W-5GAN and operator-controlled traffic steering. This scenario is further detailed in clause 4.12.2.
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Hybrid Access with simultaneous multi-access connectivity to LTE/EPC and W-5GAN/5GS using EPC interworking. This scenario is further detailed in clause 4.12.3.
In this Release of the specification, a RG that supports MA PDU Sessions and LTE/EPC access as described in
clause 4.12.2, shall also support MA PDU using LTE/EPC as 3GPP access as defined in
clause 4.12.3.
This clause applies to the case where multi-access PDU Session connectivity via NG-RAN and W-5GAN is supported in the 5G-RG and network. The Hybrid Access architecture of 5G-RG is defined in
TS 23.501 in
Figure 4.2.8.4-1. This scenario uses the ATSSS solution described in
clause 5.33 of the Release 16 version of
TS 23.501, with the following difference:
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UE is replaced by 5G-RG.
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Non-3GPP access(es) is specifically referred to wireline access.
The Release 17, ATSSS functionalities defined in
TS 23.501,
TS 23.502 and
TS 23.503 are not supported, except for the feature described in
clause 4.12.3.
This clause applies to the case where multi-access connectivity via both EPC and 5GC is supported in the 5G-RG and network. In this case, multi-access connectivity using ATSSS via both EPC and 5GC may be provided as described in this clause.
For a 5G-RG, a Multi-Access PDU Session may use user-plane resources of an associated PDN Connection on 3GPP access in EPC. This enables a scenario where a MA PDU Session can simultaneously be associated with user-plane resources on 3GPP access network connected to EPC and W-5GAN connected to 5GC. Such a PDN Connection in EPS would thus be associated with multi-access capability in 5G-RG and PGW-C+SMF.
The feature is supported as defined in
clause 5.32 of TS 23.501 (Release 17) and
TS 23.502 (Release 17) with following differences:
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UE is replaced by 5G-RG.
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5G-RG is connected to 5GC via a non-3GPP access corresponding to W-5GAN.
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MA PDU Sessions of Ethernet PDU Session type where the 3GPP access corresponds to E-UTRAN/EPC are not applicable for 5G-RG.