This is the Frequently Asked Questions (FAQ) list for KEITAI-L, a mailing list devoted to discussion of Japanese mobile telephony with an emphasis on mobile phones (keitai) that are internet-capable.

Discussions on technical and marketing issues are welcome.

  1. About this FAQ
    1. Acknowledgements
      • David Talbot supplied the initial outline.
      • Mika Tuupola provided beginner's questions.
      • Michael Turner asked: does KEITAI-L need its own FAQ?
      • Hubert Hung-Hsien Chang parsed out questions from the list, with a magic program.
      • The too-numerous-to-individually-name contributors to KEITAI-L have been, and continue to be, enormously helpful. Christopher Lowery and Danny Van Der Poel pointed out some good sites for beginning i-mode developers; Henry Minsky and Zev Blut actually supplied a couple of those sites.

        The i-mode-specific FAQ portions were inspired by the efforts of Andrea Hoffman and Robb Satterwhite on the WestCyber i-mode FAQ.

        KEITAI-L wouldn't be where it is today without the indefatigable (if somewhat laconic) Renfield Kuroda.

    2. Current maintainers
      • Mike Tuupola hosts the FAQ at
      • He, David Talbot and Kevin Markowitz offer commentary and corrections.
      • Michael Turner tries to keep it up to date.

  2. About KEITAI-L
    1. Why "KEITAI-L"?

      Keitai is what Japanese call their cellular phones (see Japanese terminology.) The "-L" is a conventional internet suffix for "[e-mail] List."

    2. History of the list
        KEITAI-L was begun because of a lack of English-language information about i-mode phones. Initial discussion about the list and its name started between Mika Tuupola and Thomas O'Dowd sometime in March 2000. The list was born in the beginning of the following month.

    3. Posting guidelines
      • To keep the list comfortable for everyone, it is advised that subscribers follow these basic rules:
        1. The preferred language is English. Discussion in any other language is discouraged.

        2. Don't post any virus warnings or chain letters to the list. Most chain letters and virus warnings are scams or at least a waste of everyone's time and computer resources.

          If you are still concerned about viruses, please consult the following URLs:

        3. Don't post test messages of any kind to the list.

        4. Don't post messages in HTML format to the list.

        5. Don't violate any copyright laws when posting to the list. When in doubt please consult:

        6. Don't send attachments to the list. Instead upload the files to a web server and post the URL of the files to the list. Please note that the MLM software strips away all the attachments sent to the list.

        7. When replying to messages please only quote parts of the message you will be discussing or that are relevant. It is especially annoying to quote the entire text of an article when just adding a few lines of comments. Overquoting is also considered bad netiquette.

        8. Be polite. Remember it is a human you are replying to.

        9. Legal disclaimer:

          The KEITAI-L mailing list (hereinafter referred as "the List") is provided as a free service to its subscribers. The list maintainer does not charge anyone to subscribe and/or participate in the List. Subscribers are, however, responsible for the charges of their own ISP (Internet Service Provider) or on-line service.

          The List maintainer is not responsible for any inconvenience or damage caused by errors in the postings or mail delivery problems.

          Opinions expressed in the postings are those of the individual posters. The expression of individual opinions does not imply any endorsement of such opinion by the list maintainer.

          Subscribers of the list are obliged to use the list in a good practice.

          The list may not be used to publish or distribute any material protected by copyrights, trademarks or other corresponding rights without the permission of the rights holder.
          Non-working email addresses are automatically unsubscribed from the List. The list maintainer also reserves the right to remove any offending email addresses and/or users from the list.
          No third party is allowed to have on-line archives of the postings of the List without written permission from the list maintainer. This prohibition does not include non-profit organisations and/or individual list subscribers archiving for their own personal usage.

          No third party is allowed to create an on-line subscription mechanism to the List. Only allowed methods of subscription are via email and/or the List'ss official web page at:

          (URL subject to change).

  3. Where can I find more information about Japanese mobile telephony?
    1. Other FAQs in English:
    2. Other mailing lists related to Japanese mobile telephony
    3. Newsgroups [Help?]
    4. WWW sites
    5. Print media and books
      • The i-mode Incident (J, book). [Author, etc.?]
      • J@pan Inc. (E, magazine)
      • "Mobile Internet Services in Japan: Identifying Industrial Organization as a Key Factor in Success". Victor Pikula (PhD diss., Erasmus University Rotterdam, Mar 7 2001). Also available in pdf. [URL?]
  4. Japanese terms for mobile-phone-related topics

    The pronunciation guide is necessarily approximate.

  5. Glosses for Acronyms and Tradenames


  6. Services: NTT DoCoMo's i-mode
    1. i-mode General
      1. What is i-mode?

        i-mode is a mobile-phone internet service operated by NTT DoCoMo in Japan.

      2. Can you "surf the Web" with i-mode?

        Sort of. Up to 500 bytes of a page anyway. You can't scroll GIFs. No Javascript. No frames. Tables? Might depend on handset. Contain your excitement. That said, there are some cool things going on.

      3. Can you send e-mail and/or short messages over i-mode?

        Yes, and this is very popular.

      4. So what does i-mode look like?

        Here are some screenshots: [Link]

      5. How many i-mode users are there?

        Lots and growing. See for yourself: [Link to DoCoMo stats?]

      6. Who uses i-mode?

        Stereotypically: the young and the female; in reality, users are far more diverse.

      7. What's the difference between WAP and i-mode?

        You had to ask, didn't you? WAP is a protocol stack, i-mode a proprietary service.

      8. Are there English sites available on i-mode?

        Yes. Some. For example, the 2000 Okinawa G7 conference had some made up specially.

      9. Who invented i-mode?

        As a user interface, mostly Mari Matsunaga. (She's the "mother of i-mode," anyway. Paternity is, of course, much more widely claimed and disputed.) Takeshi Natsuno was another leader (see Stanford course "Industry Thought Leaders Seminar" (MS&E472) talk by Takeshi Natsuno, executive director, Gateway Business Department, NTT DoCoMo ( ).

      10. What does the "i" in "i"-mode mean?

        "i" icon for "information"? Also a play on ai - "love" - in Japanese [???]

      11. Can you rent an i-mode phone on a tourist trip to Japan?

        No, you need residence status here.

      12. Can you buy an i-mode phone and take it (or send it) out of Japan?

        Only if you qualify for regular phone service in Japan.

      13. Can you buy stuff via i-mode? You know, "m-commerce"?

        Yes. And on DoCoMo "official sites," this is easy.

      14. What's an "official" i-mode site?

        These are DoCoMo-sanctioned sites, with special privileges and limitations. [details here? or link to DoCoMo?]

      15. Do you have to pay to use official i-mode sites?

        Yes, for many of them.

      16. How does i-mode official site payment work?

        The charges just show up on your DoCoMo mobile phone bill.

      17. What's a katte (unoffical) i-mode site?

        These are like regular web sites - you can put up your own without DoCoMo's blessing. [details here]

    2. For i-mode users
      1. What are the main categories?

        [details here]

      2. How do I access a site from the menu-list?

        [details here]

      3. How do I access a site outside the menu-list?

        [details here]

      4. What's an i-appli?

        A downloadable Java program for the 503-series phones. [details here]

      5. Will I get a nasty surprise when I see my bill?

        [details here]

      6. How do I sign up for content services?

        [details here]

      7. How can I stop junk mail?

        [details here]

    3. For developers of i-mode web sites
      1. What are the technical differences between i-mode and other mobile services?

        Myriad and bewildering. As a start ....[details here]

      2. What restrictions are there for developing for i-mode?

        You have to use NTT DoCoMo's dialect of CHTML, which can be handled differently by different phones. You have to write to DoCoMo's Java Virtual Machine subset as well if you are writing iAppli (i-mode applet-like applications). If you are a DoCoMo official site, there are social content restrictions. As with other keitai services in Japan, pornography is illegal. [details here]

      3. Where can I can get up-to-date information about i-mode?

        DoCoMo, for official updates. KEITAI-L, gigahz/ml and other mailing lists for rumor-stage information. [details here]

      4. What tools are available to help i-mode developers outside Japan?

        Here are some helpful sites for getting started with tools [Check?]

        A variety of emulators exist. Among the more popular and useful are

        There are some emulator classes for iAppli:

        • [more details here]

      5. What security issues should I consider with i-mode?

        [details here]

      6. Do all i-mode phones support the same mark-up language and features?

        Not exactly, no. [details here]

      7. How can I get subscribers for my service?

        Promotion is much as it is for web and online services generally. [details here]

      8. How can I become an official site?

        DoCoMo's requirements are infamously vague, but continue shifting in the direction of liberality. Here is NTT DoCoMo's official statement: [URL needed]

    4. For developers of i-appli
      1. Where can I find English language specifications for i-appli?

        DoCoMo's site. [details here]

      2. Are I-appli different from standard J2ME?

        Yes. [details here]

      3. What tools are available for developing I-appli?

        More and more every day. See Zev Blut's introduction to writing iAppli for one good start ( ).

      4. For CLDP/MIDP development there is the free-download Whiteboard SDK at
      5. [more details here]
  7. Background to Japanese wireless industry
    1. Specifics of Japanese wireless industry.

      [details here]

    2. Relative strength of carriers, keiretsu, etc.

      [details here]

    3. Evolution to PDC, etc.

      [details here]

    4. NTT DoCoMo's first attempt at a global standard

      [details here]

    5. Deregulation, privatisation of DoCoMo

      [details here]

    6. Appearance of NCC (IDO, Cellular, TU-KA, then J-Phone)

      [details here]

    7. Consumer adoption of wireless

      [details here]

    8. Current market overview; penetration etc.

      [details here]

    9. Launch of internet enabled phones

      [details here]

  8. Companies involved
    1. Cellular carriers
      1. NTT DoCoMo
      2. AU (IDO)
      3. J-Phone
      4. TU-KA
    2. PHS carriers
      1. DDI Pocket (uses NTT & KDDI ISDN network)
      2. Astel (bought by TTNET), uses Japan Telecom and KDDI's ISDN networks
    3. Handset manufacturers
      1. NEC
      2. Panasonic/Matsushita
      3. Mitsubishi Electric
      4. Sony
      5. Nokia
      6. Ericcson
      7. Motorola
    4. Network infrastructure
      1. Matsushita
      2. Ericsson
      3. Siemens??
      4. Motorola
      5. NTT DoCoMo
    5. Service Providers
      1. Contents
      2. Applications
      3. Systems integration
      4. Billing
      5. B2B services
  9. Wireless networks
    1. PDC
      1. Technical (differences with GSM)
      2. History: NTT DoCoMo's strategy: global protocol
      3. voice quality (half-rate, hyper-talk)
      4. Transition to 3G (GSM as base for W-CDMA)
    2. PDC-P
      • 9.6kbps
      • 2.5G; Comparison with GPRS
    3. cdmaOne
      • 14.4kbps, AU
      • upgradeable to cdma2000
      • path to 3G
    4. PHS (PIAFS)
      • 32/64Kbps, circuit-switched, micro-cell, handover
      • future: 128kbps pseudo-packet
    5. Pocket Bell (Pager)
      • 1980's boom: numeric Japanaese?
      • One-way
      • Two-way paging? RIM?
  10. Global roaming services
    1. DoCoMo (GSM)
    2. AU (Global Passport: cdmaOne)
  11. Wireless services (non-internet)
    1. Voice
      1. full-rate
      2. half-rate
      3. hyper-talk
      4. low quality compared with GSM.
    2. Call forwarding services
      1. One number services
      2. My line: Japan Telecom, KDDI, NTT (+others) service for home, wireless and ISP
      3. Anshin-Da-Phone: DDI Pocket service (automatically calls 3 phone numbers from registered parties)
    3. Text message services (standard)
      1. SMS in Japan (direct and via SMSC center)
      2. Why can't you send SMS messages outside Japan?
      3. Carrier dependent; low usage; low cost;
      4. Compatibiliy: Skymail to SkyWarp; P-Mail to Cellular and A-Mail
      5. Do people still use text messages/ SMS?
      6. Sky mail (J-Phone)
      7. SkyWarp mail (TU-KA) now called Sky Mail
      8. Short Message (NTT DoCoMo)
      9. Kyara-talk (direct message) (NTT DoCoMo)
      10. Kyara-mail (SMS) (NTT DoCoMo)
      11. P-Mail (DDI)
      12. Light Mail (DDI)
      13. Direct Mail (DDI)
      14. CMAIL (AU)@new version
      15. A-Mail
      16. Cellular Mail
    4. Relay mail, chat mail etc (using SMS).
      1. Chat (DDI Pocket)
      2. Co-Ordinator (J-Phone)
      3. Relay mail (J-Phone)
      4. Hot Line (J-Phone)
      5. Greeting (J-Phone)
    5. Dial-up voice content services
      1. Dial Paradise (J-Phone)
      2. Quick-Dial (Astel)
      3. #Dial service (DDI Pocket)
    6. Dial-a-melody services
      1. SkyMelody dial-up download (via Sky Mail)
    7. Dial-up text content
      1. Mozio (Astel) dial-up content and e-magazine
    8. Location based (not internet based)
      1. ima doko service
      2. P-Doko: pet finder service
      3. Pnavi: handset location monitoring from a PC (corporate subscribers only)
  12. Wireless internet services (browser phone)
    1. i-mode
    2. j-sky
    3. Ezweb
    4. H"links (Open Net Contents/@Contents)
    5. Dot.i
  13. Carrier Email services (standard)
    1. i-mode mail: one push, user-name configurable
    2. Longmail (J-sky)
    3. Ezweb mail: up to 3MB account, CC, BCC,
    4. EZ@mail : IMAP 4
    5. Dot.I mail (POP3/IMAP 4) from any PIAFS ISP
    6. "@Mail" (DDI)
    7. TU-KA (Ezweb mail)
    8. Attachments on wireless email (Deleted, recorded, viewable?)
  14. Other email solutions
    1. Gateway solutions: Orangesoft
    2. Sync solutions: fusionOne, EZ SYNC
    3. Forwarding services: Various ISPs, TelMethod etc.
    4. Unified messaging: Creative Communications; Interlinear
  15. Browser phone location based services
    1. What location information is available on Japanese wireless networks?
      1. PDC (1-2km accuracy)
      2. cdmaOne (1km)
      3. PHS (100-200m)
    2. What location based platforms are there?
      1. Dot.I (Pnavi) -- Open contents spec for catching user's location and attaching to URL
      2. Station -- J-phone's location-based info/ad service
      3. "" -- cdmaOne service (compares nearest base station signal strengths)
      4. LI -- DDI Pocket
      5. Docomo PHS on-in -- New Doccomo browser phone
  16. Wireless data services (not via built-in browser)
    1. Packet based networks
      1. DoPa
        1. DoCoMo's 28.8kbps packet data connection
        2. DoPa FreeNumber
        3. DoPa QuickNumber
        4. DoPa AccessSelect
      2. PacketOne
    2. au's 14.4-64kbps packet data connection
    3. cdmaOne X HDR (this autumn)
  17. Circuit-switched networks
    1. alpha-DATA64 (DDI)
      • DDI Pocket
      • plan for 128 kbps this summer
    2. PIAFS 2.0
      • DoCoMo PHS, 64kbps, Doccimo (PHS and keitai in-one)
    3. PIAFS 1.3?
      • Astel (32/64??)
  18. Carrier WISP (not via built-in browser)
    1. Docomo
      • Mopera (no sign up necessary, premium call charge)
    2. PRIN
      1. DDI Pocket
    3. AU
      • AU (over PacketOne)
      • Daredemo Internet
  19. Wireless data cards
    1. P-in compact -- DoCoMo (PHS) intelligent switching between 32 and 64 kbps
    2. Compact Flash -- DDI Pocket (64 or 32 kbps versions)
    3. PacketOne -- best effort 64kbps
  20. Other services
    1. Infra-red services -- Nokia 501i
    2. Data back-up services -- Address book transfer
  21. Wireless revenues plans
    1. How much does the average wireless phone user spend in Japan?
      1. On voice
      2. On packet fees (mail v. browsers)
      3. On options (answering phone, call waiting etc.)
      4. ISP service (I-mode, J-sky etc.)
      5. Premium content
    2. Basic rate plans
      • Voice
    3. Options/Discounts kurikoshi service (J-Phone)
      • gakuwari (AU)
      • Family plan (?) DoCoMo, J-Phone etc.
    4. Packet charges
      • per carrier
      • different unit charge depending on content
    5. mail charges
      • incoming/outgoing per carrier
    6. text messages
      • incoming/outgoing per carrier
  22. Facts and Figures
    1. Wireless subscribers
    2. Wireless internet subscribers
      1. browsing
      2. email
      3. m-commerce
      4. m-banking
      5. official menu access
      6. katte site access
      7. enterprise access
  23. Handsets
    1. Japanese handset market
      1. Why are Japanese phones so small?
      2. Why are Japanese-made GSM phones so unimpressive?
      3. What's the smallest phone in Japan?
      4. How have phone sizes changed since I-mode started?
      5. Why can't foreign handset manufacturers get their act together?
    2. NTT DoCoMo
      1. 501i series
      2. 502i
      3. 503i (see i-appli)
      4. DoCoMo 64 PHS browser phone
      5. Doccimo
    3. J-Phone
      1. 01-05 series
      2. Skywalker handsets
    4. AU
      1. cdmaOne
      2. Digital, IDO handsets
    5. TU-KA
      1. Cyber Giga
      2. Ferrari: Japanese keitai and European sports cars
    6. DDI Pocket/ H"
      • Hyper Carrots
    7. Astel
  24. Bilingual handsets
  25. Handset features
  26. Attachments
  27. Email terminals
    1. Pocket Board
    2. Sky Petit Pad
    3. EZPallette
  28. Multi-media terminals
    1. ToricoMail -- Camera and screen for viewing and sending (AU)
    2. PhotoPalette -- Au
    3. Sky Photo Pad -- With built in camera
    4. MelPalette -- (AU) mail and melodies
    5. M-Stage -- DoCoMo music service
    6. Eggy -- DoCoMo video service
  29. Browser terminals
    1. Exire (Exire 2) -- DoCoMo
    2. FOMA terminal -- DoCoMo
    3. WebPalette -- AU
  30. Other Adaptors