depicts the optional deployment network structure of PWS architecture in 5GS with AMF to CBC inter-connection via PWS-IWF using the reference point representation showing how the network functions interact with each other. In this option the PWS-IWF implements functionality to transfer messages between N50 and SBc reference points, and vice versa.
The PWS architecture using PWS-IWF contains the following reference points:
Reference point between the NG-RAN and the AMF.
Reference point between the PWS-IWF and the CBC.
Reference point between the AMF and the PWS-IWF.
The CBE and the interface between CBE and CBC are out of scope of 3GPP specifications.
The present document describes logical functional entities, and how these are realized in actual deployments is an implementation and deployment issue. It can however be foreseen that the PWS-IWF functionality may be co-located with the AMF, with the CBC, or deployed as a stand-alone network function. At AMF/PWS-IWF co-location, the AMF/PWS-IWF entity interacts with the CBC via SBc. At CBC/PWS-IWF co-location, the CBC/PWS-IWF interacts with the AMF via N50. At stand-alone PWS-IWF, the PWS-IWF interacts with the AMFvia N50 and with the CBC via SBc.
A PWS-IWF co-located with AMF or a stand-alone PWS-IWF may interface to one CBC or multiple CBCs (i.e. the PWS-IWF is allowed to have SCTP transport associations established with one or multiple CBCs). A stand-alone PWS-IWF or a PWS-IWF co-located with the CBC may interface to several AMFs.