How does the GSM iPhone 4 work in CDMA-only Japan?

Discussion in 'iPhone' started by ThomasJL, Mar 8, 2011.

  1. ThomasJL macrumors 6502a

    Oct 16, 2008
    Every Apple Store in Japan has sold the GSM iPhone 4 since last year. I have two questions:

    1) Since Japan only has CDMA networks and no GSM networks, how does the GSM iPhone 4 work in Japan?

    2) I hear that Softbank (which is the exclusive carrier for the iPhone 4 in Japan) provides iPhone 4 customers with a SIM card. Correct me if I'm wrong, but are SIM cards for GSM networks only? Is Softbank's SIM card for the iPhone 4 a non-GSM SIM card?
  2. robbieduncan Moderator emeritus


    Jul 24, 2002
    1) Is simply not true

    Edit to add: basically any GSM 3G phone will work in Japan.
  3. Applejuiced macrumors Westmere


    Apr 16, 2008
    At the iPhone hacks section.
    Check again.
    Japan has HSPA GSM 3G everywhere.
  4. smithrh macrumors 68020


    Feb 28, 2009
    Same answer as you got for your Korea query - they aren't CDMA-only countries.
  5. beret9987 macrumors regular

    Jun 14, 2005
    San Francisco, CA
    Rundown of Japanese Mobile Telecom:

    AU by KDDI: CDMA Carrier. Third largest if memory serves me correctly, okay footprint.

    Softbank: GSM Carrier. Exclusive carrier of the iPhone and iPad 3G. Decent network, never did me wrong in my experience.

    NTT DoCoMo: GSM Carrier. Largest carrier in Japan with the best coverage and is currently rolling out their LTE.

    Willcom: PHS Carrier. Pretty small, as PHS is being phased out(I don't understand the tech entirely never looked into it much)

    Emobile: Latest player to the Japanese mobile market, works pretty well apparently since they're using NTT's network for voice services.

    As you can see, there is only ONE CDMA carrier in Japan. The thing is though is that you need a quad-band 3G phone to work in Japan. Japan has no EDGE, GPRS, no 2G AT ALL, just 3G.

    Hope that cleared some things up for you.
  6. kandsdev macrumors newbie

    Mar 30, 2011
    iPhone 4 and NTT DoCoMo?

    Thanks for this detailed info. I am heading to Japan with my family for several years and I am looking to use an iPhone 4 with NTT DoCoMo, if that is possible. If DoCoMo is a GSM carrier and according to recent news, they will start selling SIM and microSIM cards for use with non-NTT devices after April 1, then I could use a factory unlocked iPhone 4 purchased in Hong Kong, Canada, UK, etc. and just put the DoCoMo SIM card in it. Is this correct? If so, then this sound like the best way to go. When I'm back in the US, swap in a US GSM SIM and I'm off and running. Am I getting this right?
  7. Daveoc64 macrumors 601

    Jan 16, 2008
    Bristol, UK
    The above posts are slightly wrong in the sense that Japan doesn't have any 2G (GSM) networks left.

    They DO however use UMTS (the type of 3G as used by the "AT&T" iPhone 3G+).

    That should work fine.

    As long as you have an unlocked phone and they're willing to sell you a SIM that'll work in it you'll be good to go.
  8. smithrh macrumors 68020


    Feb 28, 2009
    If you look at the end of "beret9987's" post you'll see that disclaimer.

    I'm willing to bet that this will be the hangup. They may not be willing - there are some hoops to jump through, I've been looking for a link or citation but I can't at the moment. IIRC, it's not easy for visitors to get cell service unless some or all of aforementioned hoops are successfully cleared with the requisite stamps.
  9. kandsdev macrumors newbie

    Mar 30, 2011
    Thanks for this information - I'll look into it further and see what I find.
  10. TheMacBookPro, Apr 4, 2011
    Last edited: Apr 4, 2011

    TheMacBookPro macrumors 68020


    May 9, 2008

    Japan is 3G UMTS/W-CDMA (which iPhone runs on). Not 'CDMA'.

    btw you can't purchase any SIM card in Japan without obtaining a student/work visa (not the 90 day landing visa thing thing they stamp to all visitors). No prepaid, no pay-as-you-go, no contract-free cards. The only SIM you'll be able to get with just your passport is by renting one from the multiple kiosks in Narita/Haneda.

    Or, if you walk into a Bic Camera/Yodobashi/convenience store, you might be able to buy a prepaid card without anything more than ID (they're not supposed to sell it to you, but sometimes they get lazy and do)(even so, they have to run your ID thru their system to prove that you're not a wanted criminal or something so you'll have to walk around for a while)
  11. smithrh macrumors 68020


    Feb 28, 2009
    Not sure why you're "facepalming" as KDDI most certainly is CDMA and EVDO.
  12. TheMacBookPro, Apr 5, 2011
    Last edited: Apr 5, 2011

    TheMacBookPro macrumors 68020


    May 9, 2008
    Alright, I probably should clarify.

    NTT docomo- 3G 2100 [FOMA] (iPhone OK)
    SoftBank- 3G 2100 [SOFTBANK 3G] (iPhone OK)
    AU by KDDI- CDMA 1x [WIN] (iPhone X)

    Three major carriers.

    Facepalm because OP thought Japan was CDMA only.

    Accidentally typed in W-CDMA only because I was a bit tired :eek:

  13. The Californian macrumors 68040

    The Californian

    Jan 17, 2009
    Surfers Paradise
  14. aziatiklover macrumors 68030


    Jul 12, 2011
    Location: and
    What about in South Korea? Everytime I go there and I always wonder if they were using CDMA which ppl that live tell me it is! :eek: :confused:
  15. Geckotek macrumors G3


    Jul 22, 2008
    They have both as well now. LTE in Seoul as well.

    Just got back myself. :)
  16. CineBill, Jul 3, 2012
    Last edited: Jul 4, 2012

    CineBill macrumors newbie

    Jul 3, 2012
    GSM iPhone 4s works fine in Japan.

    I live in the US. I just returned from a week long trip to Japan, where I spent time in Tokyo and Kyoto. I subscribe to AT&T in the US, which is a GSM wireless technology carrier, using UMTS/HSPA technology. I was able to use my iPhone 4S, with my AT&T SIM card intact, everywhere I went for texting, phone calls, and internet data access. Two carriers in Japan, NTT docomo, and Softbank Mobile, use UMTS technology. The iPhone 4S is capable of using UMTS. I was able to send and receive text messages, access the 3G internet service, as well as make and receive phone calls, on both the NTT and Softbank networks, with the iPhone automatically switching between them when necessary.

    Of course, you have to be aware that friends back in the US might not know you are traveling to the other side of the world, so be prepared for random phone calls at 4am in the morning, unless you turn your phone off.

    Before I left, I purchased: "AT&T World Traveler", the "Global Messaging 200", and "300 MB Data Global Add-On". That reduced the costs of phone calls, texting and data usage while I was on my trip.

    I have to tell you, being able to use the iPhone "Maps" application while trying to navigate the warren of streets in Tokyo was really helpful

    You will still find Japan Phone rental web sites stating that your US phone will not work in Japan, and you need to rent a local phone from them. If you own an iPhone 4S that is NOT true. You can use it, regardless of which carrier you use in the US.

    Just beware that unless you buy the packages I mentioned above, the use of your phone in Japan, especially for Data, might be horrendously expensive.
  17. Shadowbech macrumors 601

    Oct 18, 2011
    Planet iPhone
    South Korea uses WCDMA as we don't have GSM here in Korea. WCDMA = UMTS 2100.
  18. takeshi74 macrumors 601

    Feb 9, 2011
    No, you're using flawed logic. GSM uses SIM cards but it's not the only network tech that does.
  19. hinata42691 macrumors newbie

    Jun 5, 2012
    I am looking at getting an iPhone 4S this fall to replace my dying phone. It will be my first smartphone so please forgive my ignorance. Anyway, I just spent 9 months studying abroad in Japan (which is why my US phone is dying - spent 9 months in a drawer untouched) and am planning on moving back for a few years after I finish up college. I would really like to be able to continue using whatever phone I have in the meantime since it's a real pain to switch to a new phone every time I go back and forth. When I was in Japan I bought a Softbank prepaid phone. I also have a micro sim card for Softbank (got this from a friend who didn't need it anymore). I was hoping maybe I would be able to put the Softbank micro sim into the iPhone in Japan and at least get a prepaid plan (I'm okay with the chance that they may not let me have a contract plan) (and with the fact that the prepaid would probably not include a data plan). I would probably be getting the iPhone from Verizon (in case that makes a difference) and the sales person I talked to said that they could unlock it for international use (so I could supposedly have a US sim card and a Japanese one). I'm not sure if this is actually something that would work or if I'm being too hopeful. Any advice would be appreciated. Thank you.

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