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IE Dictionary (Information Element)

A dictionary for looking up the key information elements (IEs) carried in signaling Messages by their meaning, appearing Message, and purpose.

Related: Message Dictionary / NAS Dictionary / NGAP Dictionary / Registration chapter


IE list

IE Layer Meaning Message it mainly appears in Purpose/Notes Spec
5GS Registration Type NAS/5GMM Registration type (initial/mobility/periodic/emergency) Registration Request Indicates the purpose of registration. Encoding to be confirmed TS 24.501
5GS Mobile Identity NAS/5GMM UE identity (carries SUCI/5G-GUTI/IMEI, etc.) Registration Request, etc. The content changes depending on which identifier it carries. Encoding to be confirmed TS 24.501
UE Security Capability NAS/5GMM Ciphering/integrity algorithms (NEA/NIA) the UE supports Registration Request / Security Mode Basis for algorithm selection. Encoding to be confirmed TS 24.501
Requested NSSAI NAS/5GMM The set of slices the UE requests Registration Request Presents the requested slices. Encoding to be confirmed TS 24.501 / TS 23.501
Allowed NSSAI NAS/5GMM The set of slices the NW permits Registration Accept Notifies the slices the NW has permitted. Encoding to be confirmed TS 24.501
5G-GUTI NAS/5GMM The temporary identifier being assigned Registration Accept, etc. Assignment of the temporary identifier. Encoding to be confirmed TS 24.501
PDU Session Identity NAS/5GSM PDU session identification PDU Session Establishment family Identifies the session. Encoding to be confirmed TS 24.501
PDU Session Type NAS/5GSM IPv4/IPv6/IPv4v6/Ethernet/Unstructured PDU Session Establishment family Specifies the session type. Encoding to be confirmed TS 24.501
S-NSSAI NAS/5GSM The slice for the session in question PDU Session Establishment family The slice the session is bound to. Encoding to be confirmed TS 24.501 / TS 23.501
DNN NAS/5GSM Destination data network name PDU Session Establishment family Specifies the destination data network. Encoding to be confirmed TS 24.501
QoS Rules / QoS Flow Description NAS/5GSM QoS rules notified to the UE PDU Session Establishment family Details in the QoS Dictionary. Encoding to be confirmed TS 24.501
PDU Session Resource Setup Request List NGAP Requests DRB/resource setup over N2 PDU Session Resource Setup Request family Resource setup request on the N2 side. Encoding to be confirmed TS 38.413
UE Aggregate Maximum Bit Rate NGAP Maximum aggregate bit rate per UE Initial Context Setup family Notifies the per-UE AMBR. Encoding to be confirmed TS 38.413
Cause NGAP/NAS Failure/release reason Various Reject/Release families Details in the Cause Dictionary. Encoding to be confirmed TS 38.413 / TS 24.501

Grasp IEs conceptually

The exact encoding of IEs (IEI/length/bit layout) follows the relevant chapters of TS 24.501 (NAS) / TS 38.413 (NGAP). This dictionary is for grasping conceptually "which Message carries which IE and for what purpose". For details, refer to each Protocol dictionary and the Spec Dictionary.