Monday, May 25, 2015

Comparison of a Samsung Galaxy S6 unlocked by Japan's big three carriers

As expected, Softbank Mobile announced that it will also adhere to the new guidelines and begin unlocking phones brought new to market from this month. This includes the Samsung Galaxy S6 Edge. The terms are exactly like Docomo's: unlockable from 180 days after purchase until 90 days after the phone is disconnected. Unlocking within that 90-day window for an out-of-contract product will also require a trip to certain softbank stores and therefore cost ¥3,000 plus tax.

Unlocking terms by carrier

KDDI docomo Softbank
Free (¥3,000+tax in store) Free (¥3,000+tax in store) Free (¥3,000+tax in store)
Applicable to devices released from
April 23, 2015 May 1, 2015 May 29, 2015
Wait time to unlock
180 days 6 months 180 days
Unlock possible after cancel service
forever for 3 months for 90 days

Galaxy S6 Edge Comparison

Right now, the only phone that will be unlocked by all three is the S6 Edge.

KDDI docomo Softbank
Cost with MNP (without)
¥33,480 (¥55,080) ¥29,808 (¥58,968) ¥21,600 (¥53,760)
Earliest unlocking date:
October 20, 2015* Now November 25, 2015
Unlock cost
free ¥,3000 free
LTE Bands:
1, 3, 18, 26, 28 1, 9, 19, 21, "700"* 1, 3, 5
WCDMA (3G) Bands:
1 1, 5 (or 6?), ? 1, 5, 8
* The exact bands are ambiguous. docomo simply lists "700" which could be one of 12, 13, 14, or 17 or perhaps all may be covered because the frequencies are either adjacent or overlapping. Also, both KDDI and docomo list support for "800". KDDI specifically states this is band 18. I believe that docomo uses band 19. The uplink frequencies are overlapping and the downlinks are close but not adjacent.

Figuring out which bands are supported

KDDI is the only carrier clearly indicating this an in easy to understand way. Their bands are published here. Softbank's are on the product's specs page (SBM S6 Edge). Docomo's are also listed on the spec page, but only for LTE (DCM S6 Edge). To get the 3G bands is a real pain, but docomo will be required to make this more transparent once they release phones under the new guidelines.

Docomo classifies the S6 Edge as a "class 5 world wing" device, which looking up here gives contradictory information. The product pages lists LTE bands "2GHz, 1.7GHz, 1.5GHz, 800MHz, and 700MHz". However a class 5 world wing device supposedly supports LTE Band 1 (2.1GHz), Band 3 (1.8GHz) and "others" such as Bands 4, 17, 20 "etc" as well as "3G" (whatever the hell that means) and "3G850".
LTE(Band 1(2.1GHz)、Band 3(1.8GHz)、その他(Band 4、Band 17、Band 20など))および3G、3G850、GSMネットワークをご利用になれます。
I'm just guessing here, but since the most common 3G band (except in North America) is Band 1 (2100 MHz), I am guessing that "3G" refers to Band 1 and that 3G850 refers to Band 5 (Actually I'm told that what docomo calls "3G850" is actually Band 6). I also assume that it doesn't support AT&T's Band 2 (1900 MHz, aka PHS) or T-Mobile's Band 4 (1700/2100 MHz, aka AWS).

Digging ever deeper into docomo's i–mode-like labyrinth of a website confirms no support for 3G in North America.


  1. I'm on Y!Mobile and my Nexus 5 recently got wet/broken. I went to Nipponbashi in Osaka to buy a 2nd hand e-mobile phone. I bought a Kyocera DIGNO 302KC at a shady looking little store which I assume will no longer be there if I go again this week. When I put my Y!Mobile SIM there was a data connection so I assumed it would be good. But then I realized that I couldn't make phone calls and whenever I tried to the phone would go completely offline (no data either) until I reboot. After lots of debating with Y!Mobile it turns out the person who previously owned that DIGNO 302KC ended his contact without paying all the installments. As such the company has disabled the phone's voice call ability and I'm stuck with an 赤ロム as it's called.. If you really think about it, ever since this law is put in effect, every phone should be purchased at its full price and not split across the contract. If the person is free to move to another carrier the carriers would end up chasing people around for the outstanding installments.

  2. Docomo have a website where you can plunk in the IMEI and it will tell you if there are any contractual problems on it. I'd be surprised if the other carriers didn't have something similar.