The present invention provides a communication system for transmitting
messages from one or more dispatcher stations to and from one or more
stand-alone, two-way pagers via a radio frequency communication channel,
namely, the short message service (SMS) of the Global System for Mobile
Communications (GSM/GPRS) cellular telephone network. The paging system
of the present invention utilizes a communications protocol which allows
a dispatcher station and a pager of the paging system to communicate over
the GSM/GPRS network in a predetermined manner. When the dispatcher
station sends a message to a pager of the present invention, the message
may contain steering codes which inform the pager of the manner in which
the message is to be treated. For example, if the message is
time-critical, the pager is notified by the steering code that a response
to the message must be transmitted within a predetermined time integral.
If the pager does not transmit a response within the predetermined time
interval, the pager is not allowed to respond to the message. The
steering codes may also require that the user can respond with a
preprogrammed answer which has been previously stored in the memory of
the pager. The two-way pager allows the central station to determine the
geographical location of the pager.