A radio communication system (5) includes a transmitting unit (1) coupled to at least one controller (6). The controller (6) is adapted to subdivide the SCR's (selective call receivers) (2) into SCR groups, assign the SCR groups to supergroups, and assign a selected number of message frames (216) and message intervals (208) to each SCR group in each supergroup. A supergroup is then selected, and included in an acquisition group message. The supergroup is for directing SCR's (2) targeted to receive the acquisition group message to monitor messages during the message reception interval (203) according to the supergroup. The controller (6) then invokes the transmitting unit (1) to transmit the acquisition group message to the SCR's (2). Messages target for specific SCR's (2) are then generated, and transmitted by way of the transmitting unit (1) according to the supergroup selected. The targeted SCR's (2) receive the messages according to the supergroup received.