Saturday, May 7, 2011

Real world test of B-mobile Fair SIM

EDITED to reflect that the saving would be on my Docomo bill but not reflect the amount I paid to B-mobile.

I previously posted that, based on my actual data usage over the past year and half, using a B-mobile Fair SIM would have cost me about half of what I've paid to Docomo for my smartphone data plan. Now it's time for a real world test, so I'm going cold turkey on my Docomo paket houdai data plan.

I've disable data on my Docomo ht-03a and will be using that handset for voice only. For data, I will also be carrying around a Nexus One with a B-mobile Fair SIM. I will do this until I exhaust the prepaid 1000 MBs, or until August 10, 2011, which ever comes first.

The charge on the SIM is currently 890 MB that expires on August 10th. The test will start from today, May 7th.

While it would be preferable to start this test with exactly 4 months and 1000 MB, I used about 100 MB in mid April testing the SIM with skype, etc. Having to carry two handsets is not exactly ideal, but since I am subscribed to Docmo's two-tiered packet-houdai data plan, I have incentive not to use my Docomo handset for data, since I will actually save money if I don't.

The MyDocomo site tells me that I have used zero packets so far in May and have only incurred the minimum charge of ¥372 for data so far. (This is because I was out of Japan during Golden Week.) If the B-mobile Fair SIM lasts me for all of May, June, and July, that would be a savings of over ¥15,000 (off my Docomo bill), since this would encompass three full billing cycles.

In the interest of a "Fair" test, I will try to not change my data consumption habits. Background data, automatic syncing, and market notifications are all enabled. However, it is impractical not to make some changes to my habits, since I will no longer have an unlimited data plan. Settings I changed on the phone are:
  • Turned off picasa web album syncing.
  • Turned off automatic updating for all installed apps
  • RSS reader (new rob) is set to download only on wifi
  • Rooted to install an ad blocker (AdFree)
The most significant change I will make is using wifi when available. I purposely don't use wifi now simply because it is a drain on my battery, even though I could use it at home and at work.

This is a bit off topic, but to root the Nexus One with the Android 2.3.4 OTA installed, I:
  • booted into fastboot and fastboot oem unlock the bootloader (requires the SDK and fastboot)
  • fastboot flash recovery Amon_RA's recovery for the Nexus one
  • booted into recovery and flashed
  • removed the Gingerbread files that overwrite custom recoveries on boot (otherwise you have to reflash the recovery every time you need it)
  • installed superuser from the market to control which apps can invoke su.
  • installed busybox from the market because it is a dependency for many apps that require root.
I am not aware of any way of rooting the N1 with Gingerbread without unlocking the bootloader. There is no need to use any exploit apps.


  1. Hola-

    I've been thru your very cool site a few times and (still) trying to figure out what's my best option for a sim.

    Fantastic timing with this post:

    I'm arriving in Japan next week for a 3 month stay. I've got a Nexus One (unrooted) and this looks great.

    Could you tell me please, where can I (actually my friend in Tokyo) purchase this? How much? etc. How's the speed and coverage, and will it work for SIPgate/GoogleVoice and Skype? I take it that it doesn't have local voice...

    And for general all around use, including tethering a laptop occasionally, how do you think it compared to this:

    (and is there a 3-month version of the U300??)

    Any other SIMs to consider?

    Many thanks!

  2. how was the experience using skype on Bmobile Fair ? Lag? slow? difficult to listen?

  3. @81e42aa105d0257ee3813e1f615ccf6b:disqus : check the link at the top of the article for a quick description. Skype worked very well for on 3G, but I only made one call. It was the same quality as wifi. Talked for ~ 10 minutes.

    @twitter-9166572:disqus : Thanks. It depends on your needs.
    1. Many people use softbank because they can get the standard data plan for less than ¥6,000 per month because SB doesn't filter the flat rate APN like Docomo. But this is unsupported and requires jumping through hoops and signing contracts.

    2. If cost is not an issue, the best would be Docomo at ~ &yen10,000. Signing up could be easier or harder depending on your handset because early N1s didn't have the certification mark, even though they were certified. Technically, the only thing not certified in an N1 is the battery, but there are aftermarket batteries to bring the phone into full compliance. However, it is my understanding that a phone is unacceptable for use if it doesn't have the mark. Period.

    If you have a Docomo FOMA SIM that has an active packet houdai plan, you can put it in the N1 and set the APN to APN, and it should work with a flat rate at ~ ¥10,000 per month, but again this is unsupported and requires jumping through hoops and is just too expensive for me.

    3. U300 SIM with blue SIP would be the cheapest and you won't have to worry that your certified phone may or may not be stamped but you will run into some of the issues I listed in the link at the top of the page (3G icon, etc.) and it will be slow.

    The Fair SIM is not recommended for using SIP because you will eat into the data plan. Right now, there is no voice option for the Fair. I am sure B-mobile is considering options for this though.

    The U300 does not have a 3 month option, only 1, 6 and 12 months.

    B-mobile products that are data only can be purchased COD (cash on delivery 代金引替) and shipped to a hotel address, or purchased at major electronics stores, though not every one. Check this list

  4. If you're going to carry a second device for data, why not make it a WiMax pocket wifi? Maybe a bit more than b-mobile at 3880yen/mo (UQ flat or resellers like biccamera), but still cheaper than docomo and definitely much faster.

  5. Daniel Silva : A couple of reasons.

    I'd prefer to have just one device, so I am biding my time until LTE handsets come out and, when they do, hoping that battery life is not horrible (which it probably will be). So, I am making do with what I have available without purchasing anything new.

    If I did have a router, I'd also be concerned about battery life on the router. I'd want to have it on all the time when away from wifi so that I'd get push notifications. I am seeing around 8 hours listed on some of the wimax products I checked out. More importantly would be the drain on the battery on the handset from having wifi on all the time.Carrying around an N1 and Magic is not so bad, since the Magic is light and small. I am actually surprised how well the battery has lasted on the magic with data turned off. I am at 65% battery after 2 days 12 hours 35 minutes and 40 seconds unplugged.

  6. super. thanks again..

    yes, cheap is good! Y10,000/month is way higher than i want to pay.

    my friend with a shinjuku address can handle the paperwork and residency requirements, too, if necessary.

    and what is the "blue SIP" part of the recommendation refer to?

    i tried to find it here, but no luck:

    they list:

    Light Tab(10日間定額データ通信bモバイルSIM U300付) BM-LTBU300 4560122191360

    IDEOS (10日間定額データ通信bモバイルSIM U300付) BM-SWU300 4560122191292

    But back to the Fair - assuming it has no port restrictions for sip or skype,

    it looks like skype uses approx 1Mb/min for voice (varies widely, though)

    I don't plan on yacking on the phone too much (will find a wifi when that happens), so maybe the Fair would cut the cheese for a 11 week trip..

    and the Fair is Y10,000

    i can only find the 6-month U300's on - and at Y14,000, more yen for a slower connection (that by amazon reviews is often too slow for a skype call.)

    so how much are the 1-month U300's?? anyone find a link to buy those online? could someone please point me to an link or another good way for my friend to purchase the U300 sim for delivery?


  7. BlueSIP info. It is a different company than bmobile.

    If you use the U300, it would be cheapest to recharge the 1 month version twice. After the SIM expires, it can be charged again, as long as too much time doesn't pass. The U300 is not too slow for a skype call per se. Streams are throttled by bmobile, which is why it doesn't work. It is, however, allowed when using blueSIP, since bmobile (JCI) is the MVNE for BlueSIP. At ¥3,000 for one month of unlimited data, bmobile has to put some caps on the data usage if they want to stay in business, since they have to pay a Docomo for the packets used.

    If you keep track of you usage, though, the the Fair SIM would probably work for you. I'd suggest avoiding youtube while on 3G, though ;-)