A method and system of selectively communicating with one or more devices within pre-defined geographical zones is disclosed. A plurality of geographical zones is defined, each zone being defined by latitude and longitude attributes. A plurality of devices is associated with each geographical zone with which a portable device can communicate, the portable device having data representative of the plurality of geographical zones. The portable device also has a ground positioning unit receiver to obtain geographical coordinates of the portable device. If the portable device determines that its location is within one of the plurality of geographical zones, the portable device communicates with the devices in associated with the geographical zone.