What is tau and lau, circuit switch fall back.

Question

Accepted Answer

Tau and Lau are parameters used in circuit switch fall back (CSFB) to optimize handover between LTE and 2G/3G networks.

Tau is the time it takes for a UE (User Equipment) to switch from LTE to 2G/3G network during CSFB.
Lau is the time it takes for a UE to switch from 2G/3G to LTE network during CSFB.
These parameters are crucial for ensuring seamless handover and maintaining call continuity.
Optimizing tau and lau helps in reducing call setup time and improving network performance.
For example, if tau and lau are set too high, it may result in longer call setup time and poor user experience.

Accepted Answer

Tau-tracking area update used in 2g, now local area update in 4g, in circuit switch fall back,when call placed network automatically goes to 2g,3g.

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