Monday, April 11, 2011

Data speed comparison between Docomo and Softbank

I found on Nikkei Trendy a comparison of prices and speeds for iPhones on Docomo and Softbank. This will also apply to Android handsets. The results can be summed up in one word: "twice." In Tokyo, downlink speeds were typically twice as fast with Docomo, but the cost of service is twice as expensive.

However, in the Shonan area, along the Tokaido Line, the difference was much less. For most people, it will be difficult to justify the price of service with Docomo. It could make sense for people suffering network congestion issues in urban areas or no service in rural ares, since both the iPhone 4 and 3GS are compatible with the 800 MHz FOMA Plus Area. For everyone in between, there doesn't seem to be any compelling reason to switch, especially since you'll lose some functionality like visual voicemail, MMS, and carrier mail, as well as potentially experience less accurate cell tower location information.

First, a comparison of costs and features. The article did not properly compare uplink speeds because they compared a 3GS to an iPhone 4. The former lacks HSUPA and is limited to 384 kbps, while the latter if used on Docomo would have a theoretical maximum uplink of 5.7 Mbps (in Tokyo and other limited areas) [NOTE: 5.7 Mbps uploads are currently suspended in Kanto-Tohoku]. It seems the reason for this was the relatively lower cost of an iPhone 3GS.

Softbank NTT Docomo JCI B-Mobile
Handset Locked iPhone 4 Unlocked iPhone 3GS Unlocked iPhone 3GS Unlocked iPhone 3GS
Voice PlanWhite Plan (i) Type SS - LL value NonetalkingSIM
Data PlanUnlimited Packet Flat Packet Houdai Double Flat Data Plan
Expected Monthly Cost*¥5705 ¥11690 ¥6510 ¥3960
Data Speed**Down: 7.2 Mbps (HSDPA) UP: 1.4 Mbps (HSUPA) Down: 7.2 Mbps (HSDPA) Up: 384 Kbps Down: 7.2 Mbps (HSDPA) UP: 384 Kbps 300 Kbps symmetrical
Voice Capable×
Visual Voice Mail×××
Carrier Email×××
* Lowest price for voice plus flat rate data and standard options
** Difference in uplink speed is due to different hardware used in the test. Docomo max uplink is 5.7 Mbps.

The article also used the app to compare speeds in several areas around Tokyo and found in general better penetration underground and differences in crowded areas or on moving trains, especially during peak times. (Softbank is well known to have bandwidth issues during peak hours). It should be noted that, even though there were large gaps in performance, these were often not perceptible. Indeed, there will be no difference when receiving a text email with an uplink of ~ 300 Kbps versus ~ 750. Uploading a 5 megapixel image from Shibuya crossing at 1 pm would be frustrating, though.

Softbank NTT Docomo
iPhone 4 Unlocked iPhone 3GS
LocationDownlink Uplink Downlink Uplink
Shinjuku Station
(weekday 6 am)
2501 1231 3535 356
Shinjuku Station
(weekday 7 pm)
287 231 768 114
(weekday 1 pm)
25 1119 919 202
(Sunday 8 pm)
701 236 1443 322
Tokyo - Shinjuku
(Weekday 6 pm)
78 47 597 187
Shinjuku - Shinagawa
(weekday 6 am)
2602 1253 3150 320
Bandwidth in Kbps. Speed is the average of 5 successful tests using the app.

Outside of Tokyo is a different story altogether. There were very little differences, and at times Softbank was faster. Below are the results of testing on the platforms of different Tokaido Line stations. Each test was performed only once.

Softbank NTT Docomo
iPhone 4 Unlocked iPhone 3GS
LocationDownlink Uplink Downlink Uplink
Shinagawa (16:00)1369 1218 1461 302
Yokohama (16:20)1046 957 1832 351
Fujisawa (16:40)2040 1100 2115 355
Hiratsuka(16:53)2150 265 1771 316
Odawara (17:18)2363 262 2115 322
Atami (17:49)2339 234 1642 319


  1. FYI My result, NTT Docomo (Data Plan : Packet Houdai Double for iMode, APN : 5,985JPY/month, Downlink 113kbps, Uplink 116kbps, Server : Tokyo

  2. Thanks. I should compile a list of all Docomo APNs, including this one for the 128 k plan.

  3. Another factor which is important to me is how often my phone doesn't have any connection at all. On Softbank this used to happen to me on elevators, in underground restaurants, behind thick walls, and in mountain areas. In many of these places I now have a reliable connection on Docomo.

  4. It should have been mentioned, that Softbank allows to reduce the cost considerably, compared to the one listed in the table.

    I use "White plan + Double White plan (980円 each)", data plan "パケットし放題S" which starts from 375円, climbs up at 0.084円/packet and flats out at some point around 5000円. Voice, SMS/MMS, tethering are included. It's possible to ditch "Double White plan" to bring "expected monthly cost" to as little as 1355円 (no phone calls and zero data).

  5. Having both SB and Docomo, I completely agree with this. I work on the outskirts of central Yokohama, in a concrete building. At any given time, my Docomo has an indoor signal. SB - nada.

    And I'm only semi-ashamed to say I'm perversely tickled by iPhone4-toting co-workers walking around outside in search of the perfect spot to lock on to SB so they can make a call or send an email.

    If it were only a few specific areas this would not such a big deal. But SB signal connection makes me feel more like I'm using an Iridium phone - must be outdoors and unobstructed line-of-site.

    I haven't been on Au for awhile...I wonder how their network stacks up in this scenario?

  6. It could be mentioned that all carriers offer data plans that scale with usage and it is possible to pay much less each month if you don't use the phone at all, but, since the existence of these plans is common knowledge and this type of usage is completely unrealistic, I didn't see the need.

    Yes, the cost of setting your phone aside is cheaper than early termination, but typical usage of a smartphone for just one day is enough to reach the maximum data cost, so you will always see potential costs presented as in the table when reading Japanese because this is how 99.99% of people actually use their phones.

  7. Since when is tethering included? The option is disabled on both my Softbank iPhone 4 and my Softbank android phone. It's standard and enabled by default on all e-Mobile smart-phones, though.