Over here in the States we have always called our portable phones : Cellular phones. Or Cell phones for short. I noticed in the UK all y'all call them "Mobiles".
Which does make sense.
Last week I saw a TV commercial for some kind of Cellular service and they said "Mobile". Hmm, maybe that term is working its way over here?
PS: Yes, I am a Yankee and don't usually use the "all y'all" term. LOL
But for those not familiar with this southern US expression, Y'all is singular and all y'all is plural.