No GSM in Japan => people just don't get it
I have been living in Japan since the early 90s and I am working in the telco industry. I have been telling folks that there is no GSM in Japan for at least 15 years and it has always puzzled me how stubbornly stupid non-residents are when it comes to accepting this fact.
I have been sitting next to middle and upper management folks from the world's leading companies on long haul flights from Europe and elsewhere to Japan. It's always the same pattern. We would be talking about what we do for a living, we would exchange business cards, they would recognise that I am a resident in Japan and that I work in the field of mobile telephony, that I probably know what I am talking about when tell them that their GSM phone will not work when we land, that there was no GSM network in Japan, that the way the spectrum was cluttered had made it impossible for Japan to adopt GSM even when they finally intended to do so in 1997.
And what do these folks ALWAYS do first thing when stepping out of the airplane in Narita? They turn their GSM mobiles on and express surprise that it doesn't work. I would say "I told you there is no GSM in Japan". Many of them still don't believe it and utter something like "Maybe there is coverage once I get into downtown Tokyo". No! There won't be!
How can people be so f****ing stupid??? It's flabbergasting. What part of "There is no GSM in Japan" do they not get???
Today, there are five different mobile telephony standards in use in Japan: 1) the old NTT proprietary 2G system called PDC (still operated by DoCoMo), 2) the Japanese open standard PHS system (operated by Willcom) originally developed in rivalry to GSM and used in various other countries, 3) a modified and incompatible version of Qualcomm's CDMA-One, often called J-CDMA (now being phased out), 4) a CDMA2000 overlay on the J-CDMA system (operated by KDDI), 5) W-CDMA (operated by DoCoMo and Softbank). None of these is compatible with GSM and there never was any GSM either.
Before Softbank acquired Vodafone Japan, they intended to build and operate a network using yet another different standard, the Chinese TD-SCDMA.
3G technologies are easier to introduce in Japan because the spectrum is mostly still unused. GSM requires two bands (uplink and downlink) of contiguous bandwidth with a given fixed space between uplink and downlink. The frequencies on which GSM operates are simply not available in Japan and even if you wanted to make space for them, it would have a domino effect on just about everything else, including emergency services. If you wanted to make space in the GSM uplink band, not only would you need to move various emergency services and the Citizen Band band but you would also have to move the downlink band of the PDC and the J-CDMA system, which would require the uplink bands of those also to be moved, which would require yet other applications to be moved. The Japanese spectrum between 800 and 1000 MHz is a total mess, like a Swiss cheese. Tthe Japanese PDC and J-CDMA systems do not have contiguous spectrum, they use various bits and pieces all over the spectrum. This is the main reason why J-CDMA is incompatible with CDMA-One. They simply couldn't fit the bands in without messing up everything else. Likewise, there is no way they could fit in GSM850 or GSM900.
The situation in the Japanese 1800 MHz band is even worse. This is used for local applications such as telemetry. There are tens of thousands of license holders all over the band, all holding a tiny slice in the place they are, go to a different location and somebody else has a license to that same slice there. Any prospective mobile telephone operator who wanted to operate a GSM1800 network nation wide would have to move off tens of thousands of license holders and compensate them. Even if they have the money, just think of the time it would take to vacate the spectrum when you have to negotiate with so many parties. Why would you want to do that if you can get still unused spectrum above 2GHz?!
The 1900 MHz band (for US GSM) is also unavailable, parts of it are used by PHS and parts are used by the Japanese 3G networks now.
That leaves only GSM450. With the introduction of digital TV and the shut down of analog TV in the near future it would theoretically be possible to use the then vacated 450 MHz band for GSM, but there are already many other parties interested in that spectrum for other applications and most GSM handsets don't even support the GSM450 band. GSM450 is only used in Russia. Not much of an incentive.
As you can see, there is very little chance Japan will ever get GSM. There is certainly no GSM now and there never has been.