The radio interfaces required for a third generation personal communications network (PCN), and the attributes of an intelligent multimode portable to operate within the PCN are speculated upon. After discussing key factors in determining spectral efficiency in PCNs, multiple access methods are considered for radio interfaces associated with high-capacity network nodes, microcellular networks, macrocellular networks, megacells, satellite mobile and private mobile radio. Modulation issues are then addressed, followed by source and channel coding. Some elements of a third generation PCN are considered next. Finally the authors present their views on an intelligent multimode mobile portable that will function in many different geographical environments and, in any one, be adaptive in changing its subsystems to variations in the channel conditions and local teletraffic loading.