Originally Posted by Dubdub
Most likely wouldn't be roaming on CDMA, but on GSM. The CDMA is US freqs only, the GSM is outside the US. I had heard one of the carriers was running GSM, but that was only in the Narita airport area. Maybe they have expanded? Makes sense for a place like Tokyo to have GSM given the amount of business people and tourists who go there.
THERE IS NO GSM IN JAPAN. PERIOD.
There is CDMA1x and UMTS/HSDPA only.