How is 3G/4G Handover running and when it will be failed?

Hi All,

3G/4G Handover: how is it running and when it will be failed?

How it affect VoLTE?

Thank You

This could be as a fast return procedure after a CSFB. Usually the PS handover is not recommended for it takes a considerable amount of time.

Will fail if the coverage is not overlapping, the LTE fast return switch is off, 4G has reached its max utilisation (PRB/Users/License/eRAB/RRC), or simply the procedure fails on setuping the 4G session.

Note that, this is a way to return from the CSFB from legacy RAN, so the user was on LTE before the call itself, then made CSFB, then after call completion it made a fast return.

This whole thing will affect VoLTE attempts generally, since calls are intiated now in the legacy RANs.

The VoLTE on the other hand doesn’t require this, the call will be intiated / termintated in LTE.

I gave this answer based on the question itself, but it could have other dimensions, for instance you’re referring to PS-related service and there’s no calls involved.