
The UE modes of operation for LTE are defined in 3GPP TS 24.301 (e.g. section 4.3 in v10.3.0): * PS mode 1: EPS only, 'voice centric' * PS mode 2: EPS only, 'data centric' * CS/PS mode 1: EPS and non-EPS, 'voice centric' * CS/PS mode 2: EPS and non-EPS, 'data centric' The mode specifies, among other things, how the UE should behave w.r.t CS fallback depending on the capabilities reported by the network.