Technical reference hub for telecom engineers
Structured protocol references, message databases, call flows, troubleshooting guides, releases, and engineering tools for wireless and telecom engineers.
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Troubleshooting Guides
5G Initial Access Troubleshooting
Isolate failures in cell search, PBCH decode, SIB1 acquisition, suitability checks, camping, and pre-random-access gating.
TAI and Tracking Area Mismatch Troubleshooting
Troubleshoot TAC broadcast errors, tracking-area restrictions, roaming-area mismatch, and area-related registration reject causes.
AMF Selection and GUAMI Issues
Troubleshoot wrong AMF targeting, stale GUAMI or 5G-GUTI context, and broken AMF-selection hints across RRC and NGAP.
5G Registration Failure Troubleshooting
End-to-end guide for registration reject, incomplete registration, AMF selection issues, and first-access failures.
Initial Context Setup Failure Analysis
Diagnose failures during Initial Context Setup and isolate core, policy, or radio-side blockers.
PDU Session Establishment Failure
Diagnose failed session setup, 5GSM reject causes, policy gaps, and missing path creation.
Latest Updates
UE Radio Capability ID Mapping Request is the NGAP message sent by the AMF to the NG-RAN node to request mapping or resolution of a UE Radio Capability ID.
5G NGAP - UE Radio Capability ID Mapping ResponseUE Radio Capability ID Mapping Response is the NGAP message sent by the NG-RAN node to the AMF to return the result of a UE Radio Capability ID Mapping Request.
5G NGAP - UE Radio Capability Info IndicationUE Radio Capability Info Indication is the NGAP message sent by the NG-RAN node to the AMF to provide UE radio capability information or capability ID context for storage and later use.
5G NGAP - UE Radio Capability Check RequestUE Radio Capability Check Request is the NGAP message sent by the AMF to the NG-RAN node to ask whether UE radio capability information is compatible with NG-RAN handling.
5G NGAP - UE Radio Capability Check ResponseUE Radio Capability Check Response is the NGAP message sent by the NG-RAN node to the AMF to report the compatibility result after a UE Radio Capability Check Request.
5G NGAP - UE Context Suspend ResponseUE Context Suspend Response is the NGAP successfulOutcome message sent by the AMF to the NG-RAN node when AMF accepts a UE Context Suspend Request.