Strictly speaking, cellular phones are not just so-called
"hand phones". Phones that are permanently fixed to the car
are also called cellular phones.
In fact, now popular PCS phones are also celluar phones but people
do differentiate between PCS and cellular phones depending on the frequency
bands they use.
Portable phone may be another description of "handphone".
Anyway, most people will recognize the term cellular phone as
"handphone".