A portable radio telephone handset includes the capability of operating as a data transfer terminal as well as an analog cellular telephone subscriber station. Two modes of operation are available in the handset, an analog cellular communication mode and a Cellular Digital Packet Data (CDPD) mode. A paging function for incoming analog cellular communication is carried out on a CDPD channel. The handset distinguishes between paging signals identifying CDPD mode communications and paging signals identifying analog cellular communications. The handset automatically preempts CDPD communications in favor of analog cellular communications such as those carried out in an AMPS configuration. To maintain the security of the handset ID, AMPS communications can be set up and controlled using CDPD control channels.