A circuit-switched fallback procedure may be performed before completion of the TAU.

A CS fallback procedure handles conflict that may arise when handover operations occur during CS fallback.

When an established device-to-device link between two WTRUs is lost, one or both of the WTRUs may initiate a fallback procedure to respective fallback gateways.

The parallel operations thus speed up the circuit-switched fallback procedure and reduce existing delays in executing circuit-switched fallback from TDD-LTE to TD-SCDMA networks.

A method and system for minimizing delay in circuit-switched fallback (CSFB) procedure is disclosed.

The capacity calculation methodology shall include a fallback procedure for the case where the initial capacity calculation does not lead to any results.

If the WTRU identifier in the paging message matches a stored identifier of the receiving WTRU, then a fallback procedure to the CS RAT is performed.

A method for implementing a fallback procedure from a packet switched (PS) radio access technology (RAT) to a circuit switched (CS) RAT is disclosed.

A method and system for triggering a Circuit Switched Fallback (CSFB) procedure when a User Equipment (UE) is in a disconnected status are provided by the present invention.

A method of supporting continuation of a data session at a wireless communication device after performance of a circuit switched fallback (CSFB) procedure is provided.

Advantageously, the (release) message is sent to initiate a circuit-switched fallback procedure without having to request permission from a core network node in the first acket-switched service network.

The capacity calculation methodology shall include a fallback procedure for the case where the initial capacity calculation does not lead to any results.