Notification

Notification is a network-initiated 5GMM procedure used to alert the UE about a specific network condition that requires UE awareness or UE action. It is different from a general paging indication because the NAS Notification message carries a 5GMM-level notification type and may require a NAS Notification Response.

Signaling Sequence
Message Structure
- Example : Notification
- Example : Notification Response

Signaling Sequence

The basic procedure is simple: the AMF sends Notification and the UE returns Notification Response when the notified condition requires acknowledgement.

#	Direction	5GMM Message	Comment
1	AMF -> UE	Notification	Network informs the UE about the specific notification condition.
2	UE -> AMF	Notification response	UE acknowledges the notification when required.

Message Structure

Notification contains the 5GMM message header and a notification indication. The precise interpretation depends on the notification type. If the procedure requires acknowledgement, the UE sends Notification Response after processing the indication.

Example : Notification

The Amarisoft MME logs checked for this update did not contain a decoded 5GMM Notification instance, so the following is a constructed decoding example showing the entire message.

[NAS] DL 5GMM: Notification
        Protocol discriminator = 0x7e (5GS Mobility Management)
        Security header = 0x2 (Integrity protected and ciphered)
        Auth code = example
        Sequence number = example
        Protocol discriminator = 0x7e (5GS Mobility Management)
        Security header = 0x0 (Plain 5GS NAS message, not security protected)
        Message type = 0x65 (Notification)
        Notification indication = example

Example : Notification Response

The following constructed example shows the entire Notification Response message when the UE acknowledges the notification.

[NAS] UL 5GMM: Notification response
        Protocol discriminator = 0x7e (5GS Mobility Management)
        Security header = 0x2 (Integrity protected and ciphered)
        Auth code = example
        Sequence number = example
        Protocol discriminator = 0x7e (5GS Mobility Management)
        Security header = 0x0 (Plain 5GS NAS message, not security protected)
        Message type = 0x66 (Notification response)