Question: How does an In-Vehicle System (IVS) determine if a Public Land Mobile Network (PLMN) supports IMS Emergency Call-based eCalls for domain selection in an emergency scenario?
Option 1: Through explicit PLMN indication to the IVS, separate from other emergency call handling.
Option 2: Automatically, as part of standard eCall procedures.
Option 3: By querying the vehicle's embedded User Equipment (UE) for PLMN capabilities.
Option 4: It is assumed supported if the PLMN supports any form of emergency calls.
Explanation: According to telecom standards for emergency services, a PLMN must explicitly indicate its support for IMS Emergency Call-based eCalls to an IVS. This explicit indication is crucial for the IVS to make informed decisions about domain selection during an emergency, ensuring the call is routed appropriately and efficiently.