In a vehicle-onboard dedicated short-range communication (DSRC) apparatus for
the DSRC communication system, a command judgment unit of an electronic toll communication-security
application module (ETC-SAM) judges the type of command included in a communication
signal transmitted between a HOST and an IC card with user information held therein.
A command control unit of the ETC-SAM controls whether the command is to be analyzed,
according to a result of judgment by the command judgment unit. Therefore, it is
possible to simplify a communication procedure and reduce a communication time.
