On Thu, 31 Jan 2008, Dennis Ferguson posted:
> On 2008-01-31, Jar-Jar Binks <jarjar@nospam.com> wrote:
>> Is Japan entirely CDMA?
> No. I think the original digital standard there was a TDMA variant
> called PDC. These days I think all the companies now support 3G UMTS,
> so you can also roam with a (European) 3G phone. No GSM though.

Close, but not quite correct. There is no GSM in Japan, but not "all
companies" support UMTS.

NTT DoCoMo, Softbank, and TU-KA all have PDC networks. PDC is 2G and
pretty much unique to Japan.

Willcom has a PHS network. IIRC, PHS is also used by a carrier in Taiwan.

There is a CDMA carrier in Japan (au), with both 2G and 3G CDMA. au
operates on different frequencies than North American CDMA phones.
Consequently, North American CDMA phones can NOT roam in Japan. Some CDMA
phones in other countries can roam in Japan.

NTT DoCoMo and Softbank have W-CDMA networks, however only Softbank's is
based upon the current UMTS specification. NTT DoCoMo is based upon an
earlier version. European 3G phones should roam on Softbank's network,
but there may be difficulties in roaming on NTT DoCoMo's FOMA network.

The bottom line is that most US phones do NOT roam in Japan. Only a phone
with UMTS in the 2100 band will roam in Japan. IIRC, T-Mobile and AT&T
each have one smartphone that has that.

-- Mark --

http://staff.washington.edu/mrc
Science does not emerge from voting, party politics, or public debate.
Si vis pacem, para bellum.