Section: P.2 Activation of mobility management for IMS voice termination
Content: An MS activates mobility management for IMS voice termination when: 1) the MS's availability for voice calls in the IMS (see 3GPP TS 24.301[ Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage 3 ]  [120], subclause 3.1) changes from "not available" to "available"; 2) the MS is enabled for mobility management for IMS voice termination; 3) the IMS voice over PS session indicator received for Iu mode has the value - "IMS voice over PS session supported in Iu mode, but not supported in A/Gb mode", or the IMS voice over PS session indicator received for S1 mode has the value - "IMS voice over PS session in S1 mode supported"; and 4) at least one of the two parameters voice domain preference for UTRAN and voice domain preference for E-UTRAN as defined in 3GPP TS 24.167[ 3GPP IMS Management Object (MO); Stage 3 ]  [134] is not "CS voice only". The MS deactivates mobility management for IMS voice termination when the MS's availability for voice calls in the IMS (see 3GPP TS 24.301[ Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage 3 ]  [120], subclause 3.1) changes from "available" to "not available".