It seems that there will be at least two 3G
services available in Japan--NTT DoCoMo and
J-Phone both adopting direct-spread CDMA
(DS-CDMA), and IDO-DDI adopting cdma2000
Projected launching dates in the Kanto area are
May 2001 for NTT DoCoMo, December 2001 for
J-Phone, and September 2002 for IDO-DDI.
Regarding speeds, NTT DoCoMo claims in recent
promotional literature that its W-CDMA technology
(which is how it refers publicly to DS-CDMA) will
operate at 384 Kbps, but that in field tests
speeds of 2 Mbps were reached. I have not seen
J-Phone's projections, but I imagine that they are
similar. IDO-DDI seems to be considering using
high data rate (HDR) technology developed by
Qualcomm to deliver rates of up to 2.4 Mbps. HDR
uses asymmetric rates or 150-300 Kpbs upstream and
600 Kpbs-2.4 Mbps downstream.
All of this leaves unanswered your question
regarding shared 3G speeds of 2 Mbps. Can anybody
>I have a perhaps na$BIW(Be question - Re: the 3G 2mbps mobile
>service that will be introduced in 2002 in Japan?
>Specifically, I have heard that this is a "shared" 2 mbps.
>Can someone explain what are the implications of that for
>the actual effective data rate that will be available to
>users? Furthermore, what will be the data rate of the
Received on Mon May 29 11:52:22 2000