On Sat, 02 Sep 2006 21:06:47 -0000, Jim Logajan
wrote in :

Analog cell phones are being replaced with digital cell phones, so I fully
expect the same co-existence can be done with a changeover from analog
aviation radio to digital radio.

They operate on different frequency bands, so that is not a good
analogy unless you can get the FCC to commit to allocating frequency
spectrum for aviation use.

There would be no need to replace everything at once and I'm not sure
why you think that would need to be the case.

Because it is unlikely the FCC will agree to allocate additional
frequency spectrum for the proposed new communications system.