DoCoMo's Java Jive-Talkin'

Back to Contents of Issue: April 2001

i-Appli -- Java on i-mode -- is the coolest thing since, well, i-mode. For developers, though, its controlled rollout was a reminder of who's boss -- and how that boss likes to operate.

by Daniel Scuka

A modified version of the i-mode logo, with original images from the NTT DoCoMo i-appli advertisement.
THE LAST SATURDAY IN January saw some eight inches of snow dumped on Tokyo and its environs; there are no plows or salt trucks here and few Tokyoites own shovels, so the city more or less ground to a halt. It was also the first full shopping day for NTT DoCoMo's new Java-enabled i-mode phones, but only the most stalwart keitai fans braved the slush to get their hands on one of the shiny new 503i models. Some Java developers saw the sales-dampening weather as righteous retribution for DoCoMo's closely held handling of the Java deployment. The mobile operator, say the developers, provided Java specifications to some i-mode official Information Partner sites -- and not others -- well before Java's January 26 launch, and the firm is still keeping certain key details under wraps. While it may not be nice to fool Mother Nature, if you happen to be the owner of the most successful mobile access network of all time, it looks like you can pretty much do whatever you want.

The advent of Java on i-mode (under the "i-Appli" brand name) comes after more than a year of hurried press releases, sometimes-conflicting information, and growing industry buzz. The plan to deploy the Java programming environment on i-mode-compatible cell phones was first announced in a March 1999 joint press release from DoCoMo and Palo Alto, California--based Sun Microsystems, owner of the Java language. Many in the mobile industry here, already impressed at the dramatic success of the first, technically unsophisticated generation of i-mode, took the announcement in stride as the natural next step in the evolution of Internet cell phones.

Java, after all, was originally conceived as a simple, robust computing environment that could be embedded in ROM chips and used as the basic operating system for small, wireless-enabled computing devices, from cellphones or PDAs to set-top boxes and even the proverbial wired fridge. With Java as the OS onboard such devices, together with additional hardware like RAM memory chips, small-size, low-power processors, and enhanced input/output devices (like MPEG-4 video chips), they become much more like "real" computers. A wireless Java device can download and store files, execute applications, display dynamic Web content, and continuously update itself with newer versions of onboard software. (Although it will still take a few more product cycles before cell phones here have all of these features.)

Java, in fact, would provide the first technology boost to DoCoMo's i-mode service, basically unchanged since its launch in February 1999.

The first generation of i-mode phones could do very little outside of displaying basic Web content and downloading ringing melodies and screen backgrounds. Despite these limitations, the service went on to win some 18.7 million users as of February 2001, and DoCoMo has announced ambitious plans to expand the i-mode service into Europe (this year) and the US (next year), where it has an excellent chance of cleaning up the WAP (Wireless Application Protocol)--based competition. The hope is that DoCoMo will be able to replicate overseas the popular services now provided in Japan, such as banking, ticketing, electronic coupons, and mobile stock trading. Not bad for a service based on handsets that had no Java, very little onboard memory, and a paltry 9.6-Kbps connection to the Internet. Also, having an installed base of Java services like real-time stock reports and multiplayer games will help convince cell phone users overseas to switch to i-mode. "This will put DoCoMo well ahead of any foreign competitors," says David Moskowitz, strategy and business development director at Kansai-based Joan Touzet, CTO at Tokyo-based Internet developer Spike CyberWorks, agrees. "Java is significant," she says, "Now we can do transactions, and there's better security. But we still have to educate the customers about what Java can do." One of i-mode's strengths is the graphic content, and Java will certainly boost content owners' options with respect to animated graphics, games, and (had you forgotten?) advertisements.

But while Japan's mobile network operators would have us believe that new mobile services develop according to a master plan carefully thought out by their engineering, sales, and marketing staffs working hand-in-hand with the handset manufacturers and third-party content providers, it ain't necessarily so. The Java rollout has provided an interesting window into how DoCoMo manages, or rather, dominates, relations with its official content partners and those who would venture to offer content within the i-mode semi-Walled Garden.

In mid-1999, Sun announced that i-mode phones would use its Java 2 Micro Edition (J2ME), also being adopted by other wireless operators and device manufacturers around the world. In the case of DoCoMo's i-Appli Java service, however, sources close to the deal said that DoCoMo is actually using a modified version of the J2ME environment -- a version whose detailed specifications are known only to DoCoMo.

The closely held specifications relate to class libraries. These are onboard software components that mediate when a Java application downloaded onto a phone from a mobile Web site wishes to access the phone hardware, such as the keyboard or the display screen. Without detailed knowledge of the classes implemented by the 503i handsets, a programmer is limited to writing applications that will run only within the DoCoMo-provided onboard Java environment, and thus DoCoMo remains in de facto control of the phone, a slap at Java's open-platform and "write once, run anywhere" philosophical heritage.

While it appears that detailed class information hasn't been formally made available to anyone outside of DoCoMo (other than the 503i series handset makers), the firm did have to make the rest of the specification public to both official and non-official sites at some point. In a direct demonstration of the value of being an official Information Partner (official partners' sites are included in the i-mode default menu), sufficient Java environment information was made available to selected partners early enough to allow them to have their Java-enabled i-Appli Web sites ready to go on the January 26 official launch day -- long before any of the non-official sites. (For the launch, users of the new 503i phones could access Java games, dynamic stock quotations, and other Java-enabled content on sites operated by Cybird, Sanwa Bank, Sega, Tsutaya,, and Nomura -- some 32 in all.)

"DoCoMo published very good and detailed specifications for the i-Appli class libraries, but then stopped short of delivering the [complete] implementation to the market," explains Harry Behrens, a Tokyo-based developer. In what appears to have been a mistake, a version of the complete i-Appli Java spec was posted on a DoCoMo Web site in November last year, but it was pulled off in just a few hours and didn't reappear until December 26, a bare month prior to the i-Appli launch. The information now available (, while sufficient to let a developer write an application, still lacks the vital class library details. "We're still not getting all the information [we need] from DoCoMo," says Spike CyberWorks' Touzet.

In short, the operator kept all Java information highly confidential until the last possible minute, and then gave the most detailed info to its official partners well ahead of the public. "People who thought DoCoMo would adopt J2ME as is were dreaming," says Tim Romero, founder of software startup Vanguard KK. "NTT kept Java deployment quiet, and partners had the specs before launch; outsiders didn't. They're doing the Microsoft thing, you know, 'Java is cross-platform, except for our platform,'" he adds.

But not all developers see DoCoMo's moves as entirely sinister. Some think that DoCoMo has been as open as can be expected, short of embracing a totally open-source business model. The operator's motivation, it is argued, lies largely in protecting i-mode's tremendous brand equity, which will become especially vital when the service tries to move overseas. The technology behind i-mode (even the Java version) is not sophisticated, and what DoCoMo will really be selling its overseas partners is the brand, the business model (packet billing and subscription fee-based mobile services, among other aspects), and the know-how. DoCoMo certainly has a vested interest in protecting and nurturing all aspects of its semi-Walled Garden service offering, and that includes i-Appli. "If the user experience is not as good as expected," wrote one developer in a posting, "it could have serious consequences for DoCoMo." Vanguard's Romero agrees, surmising that outside developers are not really being prohibited from creating Java software for the i-Appli service. Providing the specs to official sites well before launch was "really just a head start," he says, adding, "By having some parts of the spec proprietary, that gives added control and additional features -- nothing wrong with that. Hopefully it locks the customer in."

It didn't take the developer community long to react when it became apparent that DoCoMo was not going to be all that helpful. Mail lists and developer Web sites have become quite active for passing on word-of-mouth information as well as sharing frustration with the mobile giant. "They always make the same mistake here: they just don't get it that by opening up the field for developers you actually boost demand, revenue, and profits," reads one posting, concluding with, "The manufacturers and DoCoMo are still wed to the concept that they make the most if they keep it all to themselves."

Philosophical gripes aside, the most keenly felt lack of assistance was DoCoMo's failure to field an official SDK (software development kit) or PC-based emulator. "DoCoMo has not opened 503i [class libraries] to the public," says Akira Sasaki, a University of Aizu student and wireless developer for The independent firm, he says, has developed its own i-Appli Java emulator since "DoCoMo won't release an official one." Others have created emulators that claim to model the i-Appli environment, and so far there's no word on which is best (see sidebar).

In the absence of any official assistance, one of the few ways to create a working emulator is to download a Java application and then decompile it to tease out the class library and other details. "I decompiled an unofficial appli, and the official calls correspond to what DoCoMo's documentation said they should/would be," admitted one developer. But, "Decompiling is a big no-no," warns Romero. "While it may not be strictly illegal, I've never seen or prepared a software licensing agreement that didn't prohibit it. It may be OK for an engineer who is trying to figure out how something works, but it's not allowed for commercial development." Of course, any developer who did so would argue that site owners don't require a user to sign a licensing agreement prior to downloading, say, Java Tetris, so they're free to do what they want with the software once received.

But the high-handed treatment developers have received from DoCoMo may not be anything personal. After all, DoCoMo has far more on its plate than just the Java rollout, and the firm may simply be too busy to devote anything more than token resources to assist outside developers. (NTT DoCoMo declined to comment for this story in view of regulatory requirements related to its new share offering.)

While the operator struggles with managing the phenomenal growth of i-mode (last year saw several embarrassing service outages due to network congestion and i-Appli Java applets have been limited to 10KB, partly due to processor limitations and partly so as not to swamp the servers), it is also trying to launch the world's first 3G mobile network. Speaking at a conference in Tokyo late last year, Shiro Tsuda, executive vice president at NTT's Network Headquarters, said the company is on schedule for introduction of commercial 3G services (known locally as IMT-2000) in May this year.

According to DoCoMo's plans, 3G will eventually provide 384-Kbps wireless download speeds and is expected to utterly transform the current 2G and 2.5G offerings. 3G's bandwidth will enable streaming video and audio, and content providers are drooling over the prospect of offering music and video download, not to mention TV-style advertising. But, at least in the beginning, there is no guarantee that all users will receive the 384-Kbps level of service at all times, as network congestion will affect data traffic. In fact, says Tsuda, "3G service deployment will initially be limited while testing takes place." At 3G's launch, data speeds will be limited to some 64 Kbps until DoCoMo sees how the network bears up. Also, there is pressure to boost the mobile computing experience on all the major operators here -- not just DoCoMo. "To increase market share, one challenge for the operators is to introduce new applications," says Dr. Hideo Okinaka, head of technology strategy in KDDI's Strategic Mobile Communications Planning Division.

But DoCoMo's Java rollout has not been the only example of DoCoMo throwing its weight around. Despite senior managers' repeated pronouncements that the company is a network operator, and is not in the content business, at least one regional arm of DoCoMo has started to build its own portal-like site optimized for both desktop and i-mode. NTT DoCoMo Kanagawa's Mobile Bay site ( offers shopping, local information, links, and entertainment. "I think [this site] competes with the independent content providers that helped build [i-mode]. I understand that they are trying to ensure high-quality content for their customers, but this will restrict competition," says iKaiwa's Moskowitz.

But whether it's steam-rolling independent content providers or man-handling third-party Java developers, DoCoMo's tendency to look out for No. 1 will probably only increase. The hard reality is that DoCoMo is the sole arbitrator of what happens on i-mode and will do everything it can to maintain control of the brand, the platform, and the service envelope. Independent developers who aren't members of the official family are probably safe in concluding that when new technologies like Bluetooth, streaming audio and video, videoconferencing, smart cards, and position-based services come online, they will probably be left out in the cold. Again.

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