5G NR Measurement Events & Signaling events

About 5G NR Measurement Events :

The events are defined in 3GPP TS 38.331 for NR and TS 36.331 for LTE used to make sure efficient mobility management and handover management in 5G and 4G networks. 

These events are used to trigger specific actions and procedures in user equipment (UE) and the network when certain conditions are met. 

By doing so, the network can ensure seamless connectivity and optimal performance for mobile devices as they move within the coverage area.

The events are defined in TS 38.331 release 17 cover various scenarios, such as detecting when a UE moves towards the cell edge, identifying stronger neighboring cells, or determining the need for handover due to changing radio conditions and keep users experience reliable and high-quality connectivity while on the moving conditions. These events help in:

Handover Optimization: 

Ensuring that a UE is handed over to a different cell or frequency when the current connection quality degrades, thereby maintaining a stable and uninterrupted service.

Radio Resource Management: 

Efficiently managing radio resources by triggering measurements and mobility procedures only when necessary, reducing unnecessary signaling and network load.

Seamless Connectivity: 

Enabling smooth and seamless transitions between different cells and frequencies, providing a consistent user experience during mobility.

Network Efficiency: 

Optimizing the network's performance by making intelligent decisions based on real-time radio conditions and user equipment capabilities.

Event Type	Purpose of events
Event A1	Serving becomes better than threshold
Event A2	Serving becomes worse than threshold
Event A3	Neighbour becomes offset better than SpCell
Event A4	Neighbour becomes better than threshold
Event A5	SpCell becomes worse than threshold1 and neighbour becomes better than threshold2
Event A6	Neighbour becomes offset better than SCell
Event B1	Inter RAT neighbour becomes better than threshold
Event B2	PCell becomes worse than threshold1 and inter RAT neighbour becomes better than threshold2
Event I1	Interference becomes higher than threshold
Event C1	The NR sidelink channel busy ratio is above a threshold
Event C2	The NR sidelink channel busy ratio is below a threshold
Event D1	Distance between UE and referenceLocation1 is above threshold1 and distance between UE and referenceLocation2 is below threshold2
CondEvent T1	Time measured at UE is within a duration from threshold
Event X1	Serving L2 U2N Relay UE becomes worse than threshold1 and NR Cell becomes better than threshold2
Event X2	Serving L2 U2N Relay UE becomes worse than threshold
Event Y1	PCell becomes worse than threshold1 and candidate L2 U2N Relay UE becomes better than threshold2
Event Y2	Candidate L2 U2N Relay UE becomes better than threshold