A table (328) is created (402) for mapping, for ones of a plurality of portable subscriber units (122), a plurality of message types to a corresponding plurality of locations. A message matching one of the plurality of message types is then received (404) by a controller (112), the message intended for a portable subscriber unit. In response, the controller and the portable subscriber unit cooperate to determine (406) the location of the portable subscriber unit. The controller sends (428) the message to the portable subscriber unit when the location matches one of the plurality of locations corresponding to the one of the plurality of message types.