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:
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.
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:
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.
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 184.108.40.206-1
. This scenario uses the ATSSS solution described in clause 5.33
of the Release 16 version of TS 23.501
, with the following difference:
UE is replaced by 5G-RG.
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:
UE is replaced by 5G-RG.
5G-RG is connected to 5GC via a non-3GPP access corresponding to W-5GAN.
MA PDU Sessions of Ethernet PDU Session type where the 3GPP access corresponds to E-UTRAN/EPC are not applicable for 5G-RG.