I would rather have one address for a wireless WAN interface and
another address for a wireless LAN interface -- which seems to be
doable today -- much more than I want to wait for the solution
with "Mobile IP" address traversal to become commercially available.
No, what you want is a serial number. Or at least what you describe
is a serial number. An address is very different.
the word "address" is used in so many different ways that any
argument of the form "x is/is not an address" tends to be
nothing more than an argument about which definition of the
word "will be master" (to quote Humpty Dumpty)
users don't care about whether their mobile device has one address
that follows it everywhere or whether it changes addresses as
it moves. however, depending on their needs, they might care about
their applications continuing to stay connected while they're mobile.
they might also care about running applications that are both mobile
and "always on".
any network stack that supports the latter two kinds of applications
will almost certainly employ (at least) two different sets of
things that could be called "addresses" - one which is stable
even while the device is mobile, and another which is less stable.
whether those two addresses look alike or different, whether
the technology used is "mobile IP" or something else , and
the level of the protocol stack at which the indirection occurs
- these are implementation choices.
of course, some implementation choices work better than others,
especially when it comes to interoperating with the wired Internet,
or in being able to support existing applications, or in being
able to switch from one communications medium to another. but
the implementation choice can quite reasonably be different
depending on the particular characteristics of the device and
its communications media, and also on the needs of its users.
Ketih