Section: 4.3.33.2 Connection Release
Content: A Multi-USIM UE may request to be released to ECM-IDLE state for a USIM due to activity on another USIM if both the UE and the network indicate to each other the Connection Release feature is supported. A Multi-USIM UE indicates that it requests to be released to ECM-IDLE state for the USIM by initiating the Service Request procedure (using Extended Service Request message) or a Tracking Area Update procedure if the UE needs to perform Tracking Area Update at the same time with this network (including the case where the Tracking Area Update is performed due to mobility to a Tracking Area outside the current Tracking Area List, i.e. before detecting whether the network supports the feature in the new Tracking Area, provided that the network has already indicated support for Connection Release feature in the current Tracking Area List), by including a Release Request indication. If supported by the UE and network, the UE may also provide, together with the Release Request indication, Paging Restriction Information, as specified in clause 4.3.33.6, which requests the network to restrict paging. NOTE: When there is no PLMN-wide support for the Connection Release feature, it can occur that upon tracking area update with Release Request indication the UE is not released by the network. The UE behaviour, when it detects that the network does not support the feature in a new TA, is outside the scope of this specification.