The present document describes key issues and solutions for the phase 2 of the system enhancements for Edge Computing in 5GS.
Edge Computing is supported in 5GS since Rel-15. During Rel-17 FS_enh_EC study described in TR 23.748, further enhancements for supporting Edge Computing have been studied, including discovery and re-discovery of EAS, edge relocation etc. 4 key issues from FS_enh_EC study have been concluded and progressed in TS 23.548. Some other issues were raised during the Rel-17 study but not studied due to the time limitation in Rel-17.
This technical report will document the study of potential system enhancements for enhanced edge computing support, including:
improvements to roaming, to support access to EHE in a VPLMN (WT#1);
defining use cases that may benefit from exposure of additional data via the Local UPF/NEF including describing (on a high level) the characteristics of the data and data delivery to fulfil the use cases; investigating the solutions and their feasibility and suitability for improved network exposure of UE traffic related information to common Edge Application Server via Local UPF/NEF, such as network congestion status (WT#3);
investigating the potential need and solutions for supporting offload policies to match more granular sets of UE(s) without exposing operator-internal configurations to 3rd party AFs (WT#5);
investigating the potential need and solutions to influence of PSA-UPF and EAS (re)location for collection of UEs, e.g. in scenarios when UE(s) should use the same EAS and are not members of a pre-defined group (WT#6);
investigating potential impacts related to the GSMA Operator Platform Group work, and potential improvements related with 5GC and EHE being operated by different organizations (WT#7);
investigating the potential need and solutions to avoid the UE to switch the EC traffic away from the EC PDU Session and 5GS altogether, due to conflicting connectivity preferences in the device (e.g. via means outside of 3GPP connectivity, e.g. non-integrated Wifi) (WT#8);
investigating the potential solutions for the AF to be able to obtain/determine the DNAI that is associated to a certain selected EAS, for subsequent use with already defined services provided to the AF (WT#9).
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
For the purposes of the present document, the terms given in TR 21.905, TS 23.501, TS 23.548 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905.
For the purposes of the present document, the abbreviations given in TR 21.905, TS 23.501, TS 23.548 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.
Existing solutions defined in Rel-15, Rel-16 and Rel-17 will be considered as baseline in this study.
The architecture for support of Edge Computing in 5GC shall be based on the following architecture assumptions:
the architecture for Edge computing specified in Release 17 is used as basis for further potential enhancement;
the Edge Hosting Environment (EHE) can be under the control of the serving network operator or a 3rd party;
interconnectivity between EHEs of different operators cannot be assumed to be available for all deployments.