Can I use my phone in Japan?
Depends on the technology.
GSM phones:
No. GSM is not deployed in Japan. If you just would like to use your GSM SIM card (i.e. make/receive calls with your usual number) in Japan, buy or rent a W-CDMA (UMTS) phone, put your SIM card in it and it can roam in Japan. See below about W-CDMA roaming.
cdmaOne/CDMA2000 phones:
Some CDMA phones can roam in Japan. Ask your operator.
W-CDMA (UMTS) phones:
Yes. They can roam in Japan. Your operator must be an inbound roaming partner of DoCoMo or Vodafone Japan. Be careful that DoCoMo's reception may be very poor because most of FOMA network is still based on an older version of W-CDMA technology and foreign W-CDMA phones may be incompatible with it. Some foreign W-CDMA phones (such as Motorola A835) are known to be compatible with FOMA network.
