uring UE mobility. 5G NSA - option 3 call flows In this section, we will dig into details of the call flow of 5G UE connected to an option 3x-based NSA network. Let us go over the initial registration call flow step by step: 5G NSA - option 3 call flows 5G NSA - Call Flows - Initial Registration M-eNB S-EN-gNB SAEGW-C SAEGW-U NAS [Attach Request (DCNR)] [PDN Connectivity Request] UE Network Capability = {DCNR bit, ... S1AP Initial UE Message [Attach Request (DCNR)] [PDN Connectivity Request] UE Network Capability = {DCNR bit,...) Successful Authentication of UE Diameter Update Location Request Feature-List-ID-2 (NR as Secondary RAT} Diameter Update Location Answer UE network capability IEI octet Length of UE network capability contents octet 2 octet 3 Feature-List-ID-2 (NR Secondary RAT}, Max-Requested-Bandwidth-U 4294967295 octet 4 Max-Requested-Bandwidth-DL= 4294967295 bps, octet 5 Extended-Max-Requested-BW-UL, octet 6 ProSe H.245. Extended-Max-Requested-BW-DL ProSe-dd octet 7 HC-CP ERw/o S1-U data UP Clot CP Clot Prose relay ProSe-do octet 8 GTPV2 Create Session Request O Spare Nimode CP backoff Restrict V2XPCS multiple DRB octet9 Spare octet 10-15 AMBR IE {5G like APN-AMBR values} UP Function Selection Information Flags DCNR=1 Diameter Credit Control Request-Initial (CCR-I) Feature-List-ID-2 (Extended-BW-NR), APN-Aggregate-Max-Bitrate-UL = 4294967295 bps, APN-Aggregate-Max-Bitrate-DL= 4294967295 bps, Extended-APN-AMBR-UL Extended-APN-AMBR-DL Diameter Credit Control Answer-Initial (CCA-I) Feature-List-ID-2 (Extended-BW-NR), APN-Aggregate-Max-Bitrate-UL = 4294967295 bps, APN-Aggregate-Max-Bitrate-DL = 4294967295 bps, Extended-APN-AMBR-UL. Extended-APN-AMBR-DL Figure 10.8 - Option 3x call flow part 1 Consider DC-capable UE that moves into the coverage area of a 5G NR radio; the UE sends an Attach Request message to the master eNB, and the Packet Data Network (PDN) connectivity request has a UE Network Capability field with a Dual-Connectivity with New Radio (DCNR) flag on. Since all signaling is handled by the m