What is a tracking area update?
Tracking Area Update(TAU) in LTE is similar to a Location Area Update/Routing Area Update in GSM and WCDMA. Normal TAU – It is initiated when the tracking area on which the UE is attached is different from the previously registered cell or when UE re-selects/does handover from 2G/3G to LTE.
What is TAC and Tai in LTE?
In the right side of the figure are a Tracking Area Identifier (TAI) and a Tracking Area Code (TAC). A TAC is the unique code that each operator assigns to each of their TAs (e.g. TA1=0x0001 for A neighborhood, TA2=0x0002 for B neighborhood, etc.). A TAI consists of a PLMN ID and a TAC.
What is tracking area code in LTE?
The tracking area code (TAC) identifies a tracking area within a particular network and if we combining this with the PLMN-ID then we arrive at a Globally Unique Tracking Area Identity (TAI).
When does UE start tracking area update procedure?
A UE starts the Tracking Area Update procedure in following events: When a UE moves to a new Tracking Area which is not included in its list of Tracking Areas with which the UE is registered. When the timer T3412 expires the UE triggers the Tracking Area Update procedure.
When does UE trigger tracking area update call flow?
When the timer T3412 expires the UE triggers the Tracking Area Update procedure. The value of T3412 is initialised in the Attach Accept message during the Attach procedure. Registering with the CS domain for non-EPS service when the UE is already attached for EPS services.
Where is the tracking area update request sent?
So the Tracking Area Update Request message is sent within the RRC Connection Setup Complete message. If the UE is already in RRC Connected state when TAU procedure is triggered, the Tracing Area Update Request is sent within an Uplink Information Transfer message. Posted in 3GPP
When to request acknowledgement for UE configuration update?
The AMF should request acknowledgement for all UE Configuration Updates, except when only NITZ is provided. If Registration procedure is not required, steps 3a, 3b, 3c and step 4 are skipped.