Multiple Frequencies

[extremewanderer]

I read somewhere that cell phones, or two way radio phones, use
multiple radio frequencies simultaneously, that is how while talking
on cell phones, we are able to talk and hear at the same time. There
is one frequency for talking, one through which we receive the
other's
voice, and there are more for data transfer from the mtso. Is this
true?? If so, do cordless telephones, commonly used at homes, also
use
two frequencies simultaneously??
Gkg

[Day Brown]

there's lotsa tricks. they may also scan for empty channels, and jump
from one to another depending on noise. They can also record the sound,
compress that, then send it, 'half duplex', with each end using the same
frequency and trading back and forth which sends packets.

Or spread sets of packets out among several different frequencies, and
using spread spectrum to avoid the noisy ones.