(1) why?
there are two networks, the radio one and the cable (core) one.
the UMTS 3G system is basically a new CDMA air interface on top of
the old GSM/GPRS core network, which is a well defined system
compared with IS-41.
Americans, like Qualcomm, are very good at radio technologies.
cdmaOne/cdma2000 used to be and is still the best, at least better
than the UMTS (UTRA-FDD) air interface.
the European-Japanese designers preferred to use the umbrella term
W-CDMA when they mean UMTS, believing that would be the only system
to prevail and dominating the world ... a nice wish.
(2) comparisions
why the newly designed UMTS failed to be a better system? I think
the lack of experience and political decisions should be blamed.
the cdma2000 is not only leading in technology, but also economy.
that's why au/KDDI is the most willing company into price wars.
but UMTS and cdma2000 shouldn't be very different. in general,
any new development in one system should be able to be applied to
and benefit the other.
(3) better systems
btw, both systems are frequency division duplex (FDD), which is
okay for voice/video but not data, a big joke for 3G systems.
obviously DoCoMo had no knowledge of wireless multimedia when
they designed FOMA. (they do have 64 kb/s circuit data which
cdma2000 cannot provide.)
TD-CDMA and UTRA-TDD should be better systems. the Siemens-Chinese
TD-SCDMA is a great radio system ... with some problems yet solved.
the star of UMTS will be the HSDPA over all-IP network, which
DoCoMo is working hard with, and Vodafone.jp has also to catch up.
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Received on Thu Sep 2 01:41:54 2004