A time slot for a connection request sent from a mobile station includes
the mobile station ID and the application discrimination word of the
object application for which the mobile station requests the connection.
By referring to the database, a base station assigns a MDC preferentially
to a mobile station issuing a connection request for calling a high
priority application. The base station monitors the MDCs used for ongoing
communications. If a MDC assigned to a mobile station does not satisfy a
predetermined radio communication quality, other MDCs for lower priority
application are freed and reassigned to the mobile station. A plurality
of MDCs including the reassigned MDCs into which the same contents are
encapsulated are transmitted to the mobile station.