3 Definitions and abbreviations

23.2723GPPCircuit Switched (CS) fallback in Evolved Packet System (EPS)Release 17Stage 2TS

3.1 Definitions

For the purposes of the present document, the terms and definitions given in TR 21.905 [1] apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905 [1].

1xCS: The 3GPP2 legacy circuit Switched signalling system as defined in 3GPP2 X.S0042-0 [22].

CSMT flag: A flag in LA update request message used in CS fallback for MT call to avoid missing paging in roaming retry.

CSMO flag: A flag in CM Service Request and LA Update request message used in CS fallback for MO calls.

Service User: See TS 22.153 [36].

3.2 Abbreviations

For the purposes of the present document, the abbreviations given in TR 21.905 [1] apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905 [1].

1xCS IWS Circuit Switched fallback Interworking solution Function for 3GPP2 1xCS.

CSMT Circuit Switched fallback Mobile Terminated call.

CSMO Circuit Switched fallback Mobile Originated call.

DRX Discontinuous Reception

eMLPP enhanced Multi Level Precedence and Pre emption

ICS IMS Centralised Services

MNRF Mobile Station Not Reachable Flag

MNRF-MME Mobile Not Reachable Flag in MME for SMS

MPS Multimedia Priority Service

MTRF Mobile Terminating Roaming Forwarding

MWD Message Waiting Data

NAM Network Access Mode

NEAF Non-EPS Alert Flag.

PSM Power Saving Mode

SRVCC Single Radio Voice Call Continuity