UE mode of operation

A UE attached for EPS services shalloperate in one of the following operation modes:

-     PS mode 1 of operation: the UE registers only to EPS services, and UE's usage setting is "voice centric";

-     PS mode 2 of operation: the UE registers only to EPS services, and UE's usage setting is "data centric" or the UE has no CS voice capability;

-     CS/PS mode 1 of operation: the UE registers to both EPS and non-EPS services, and UE's usage setting is "voice centric"; and

-     CS/PS mode 2 of operation: the UE registers to both EPS and non-EPS services, and UE's usage setting is "data centric" or the UE has no CS voice capability.