Section: 5.16.4.10 Support of eCall Only Mode
Content: For service requirements for eCall only mode, refer to TS 22.101[ Service aspects; Service principles ]  [33]. A UE configured for eCall Only Mode shall remain in RM-DEREGISTERED state, shall camp on a network cell when available but shall refrain from any Registration Management, Connection Management or other signalling with the network. The UE may instigate Registration Management and Connection Management procedures in order to establish, maintain and release an eCall Over IMS session or a session to any non-emergency MSISDN(s) or URI(s) configured in the USIM for test and/or terminal reconfiguration services. Following the release of either session and after the UE has left RRC_CONNECTED state, the UE starts a timer whose value depends on the type of session (i.e. whether eCall or a session to a non-emergency MSISDN or URI for test/reconfiguration). While the timer is running, the UE shall perform normal RM/CM procedures and is permitted to respond to paging to accept and establish an incoming session (e.g. from an emergency centre, PSAP or HPLMN operator). When the timer expires, once the UE is not in RRC_CONNECTED state, the UE shall perform a UE-initiated Deregistration procedure if still registered and enter RM-DEREGISTERED state. NOTE 1: An HPLMN operator can change the eCall Only Mode configuration state of a UE in the USIM. An HPLMN operator can also instead add, modify or remove a non-emergency MSISDN or URI in the USIM for test and/or terminal reconfiguration services. This can occur following a UE call to a non-emergency MSISDN or URI configured for reconfiguration. When the eCall Only Mode configuration is removed, the UE operates as a normal UE that can support eCall over IMS. NOTE 2: A test call and a reconfiguration call can be seen as normal (non-emergency) call by a serving PLMN and normal charging rules can apply depending on operator policy. NOTE 3: An MSISDN configured in the USIM for test and/or terminal reconfiguration services for eCall Over IMS can differ from an MSISDN configured in the USIM for test services for eCall over the CS domain.