well,
surely - you can wake modern x86/x64 by phone if your machine have a modem and does support wake on ring .
but at this topic "maybe" - the point is that we must have PXE capable NIC right - to support wake on LAN?
DHCP + TFTP + boot file/image - etc.
but - actually its all about apps (terminal/remote install etc) that runs on top of it.
i mean - why you wake the machine if you dont have anything to do with it?
cheers