LTE to 3G UMTS circuit switched fallback
LTE to 3G UMTS CSFB call flow
Describes the complete flow of circuit switched fallback from an LTE network to UMTS. You can click on most messages in the flow to reveal full details about individual messages.
Interactions between LTE and 3G
Summary call flow that focuses on the interactions between 4G and 3G networks for establishing a circuit switched call.