| 摘要 |
The present invention relates to a mobile communications system, and particularly, to a method for determining whether to keep or deactivate an activated Idle mode Signaling Reduction (ISR) feature for a terminal in a mobile communications system. In case of the UE's intra-SGSN mobility and intra-MME mobility, when deciding, by a mobility management node, ISR activation for a UE in an IMS network environment where heterogeneous mobile communications networks (e.g., E-UTRAN and UTRAN/GERAN) interwork with each other, considered are not only whether the mobility management node can support an ISR feature, and whether the UE can use IMS voice, but also conditions (information) on whether each mobility management can support IMS voice over PS session. This may allow an incoming voice call to the UE from the IMS network to be delivered through a first trial, to a domain (PS domain or CS domain) selected with consideration of access network situations. |
