Get a specific TransmissionDescriptor and its associated distinguishing information.

Operation Exceptions:
1. NOT_IMPLEMENTED - Raised when EMS does not support this operation.
2. INTERNAL_ERROR - Raised in case of non-specific EMS internal failure.
3. INVALID_INPUT - Raised when transmissionDescriptorName does not reference a TransmissionDescriptor object.
4. ENTITY_NOT_FOUND - Raised when the requested TransmissionDescriptor does not exist.
