The UMTS world has a lower-layer protocol called HARQ in the radio air
interface which functions a little like TCP; the idea is to detect dropped
packets on the radio link and retransmit them before the TCP interval times
out, thus providing faster recovery. I wouldn't be surprised if there is a
similar mechanism to police the use of spectrum; and a lot of mobile operators
see "Internet" as an application. Somewhere around I have the incredibly long
referral string Vodafone sent my blog server not long after they started real
Internet service; a Squid, a Novarra, a 724 Solutions machine of some sort,
and I think something else too.