A mobile radio system comprises first through N-th radio base stations,
where N represents a positive integer which is greater than one. On a
start-up sequence of an n-th radio base station, a base station control
apparatus transmits an n-th individual identifier as a station identifier
to the n-th radio base station to allocate the n-th individual identifier
to the n-th radio base station, where n is a variable between one and N,
both inclusive. The base station control apparatus transmits a
transmission message signal having the n-th individual identifier as a
transmission individual identifier to the n-th radio base station to
carry out a link connection between the base station control apparatus
and the n-th radio base station. In the n-th radio base station, an ATM
reception section compares the transmission individual identifier with
the n-th station identifier to abandon the transmission message signal
when the transmission individual identifier is not coincident with the
n-th station identifier. A CPU makes the ATM reception section become a
reset state when the ATM reception section continues to abandon the
message signal during a predetermined time duration.