that's right - they use iMODE on the DOCOMO mobiles. iMODE and
WAP seem to have that in common: a non-IP radio link protocol
and an application gateway. Of course, this limits the applications
to those that can be "translated" in the gateway, while an end to
end system (such as the Ricochet from Metricom) would allow
essentially any application on an Internet server to interact
directly with the mobile device because the gateway would merely
be an IP level device, possibly with NAT functionality.
With a JAVA interpreter or other similar capability in the
mobile, one could imagine considerable competition for development
of new applications. As it stands, only the applications NTT
chooses to implement in the translating gateway are accessible.
An interesting thing is that iMODE is so successful that DOCOMO
is suffering from the usual problems (lack of scalability and
robustness) caused by violating the end to end principle.
iMODE is now infamous for its frequent service interruption.
DOCOMO users are refunded for the interruption.
Since HTTP is one of the "applications" served, there is still
a lot of room for competition, I suppose.
To make the competition fair, the important questions are:
Is it fair if providers using iMODE or WAP are advertised
to be ISPs?
Is it fair if providers using NAT are advertised to be ISPs?
My answer to both questions is
No, while they may be Internet Service Access Providers and
NAT users may be IP Service Providers, they don't provide
Internet service and are no ISPs.