Question: What does Cause No. 58 indicate in a mobile network?
Option 1: The mobile station has requested an unsupported bearer capability.
Option 2: The mobile station has insufficient resources to establish a call.
Option 3: The network is experiencing congestion and cannot process the request.
Option 4: The requested bearer capability is implemented but currently unavailable.
Explanation: Cause No. 58 specifically indicates that the requested bearer capability is implemented by the equipment generating this cause, but it is not available at the time of the request. This means that the capability exists in theory but cannot be utilized due to current conditions or limitations.