What Is I-mode?

photo of John Michael Pierobon By: John Michael Pierobon

The Japanese are wild about surfing the Web on their cellular telephones. This phenomenon is called i-mode.

First introduced in Japan in February 1999 by NTT DoCoMo, the mobile communications arm of NTT, i-mode is the world's most successful wireless Web and electronic mail service for mobile telephones.

Tens of millions of Japanese, mostly teenagers and young adults, are using i-mode to build networks of friends, follow the stock market, look up train schedules, download screen savers and music, etc. There is a growing list of official, and unofficial, i-mode Web sites which are adding content to enhance the i-mode experience.

The popularity of i-mode is due to several factors, including price. In Japan, local telephone calls are expensive and charged by the minute, while i-mode users are charged by the amount of data they send or receive, and not by the amount of time they are connected. In fact, in Japan, thanks to i-mode, it is cheaper to send electronic mail than to make a one minute telephone call.

Home computers are not as common in Japan because space is at a premium in Japanese homes, and because composing Japanese characters on keyboards is difficult and cumbersome. So, i-mode has become a cheaper and much more compact alternative to getting on the Internet.

Convenience is another reason why i-mode is so popular. Purchases of third-party goods and services made by subscribers are added to their monthly cellular telephone bill.

Because i-mode is always on, there are no latencies associated with using it. The irony of i-mode is that it seems fast, yet i-mode transmits at only 9600 bps. Compared to a V.90 modem this is very slow.

Electronic mail messages are short, limited to only 500 bytes, or 250 double byte Japanese characters, with no attachments. Most i-mode Web pages are simple and relatively small, made up of mostly of text data with very few graphics. Even animated GIF images are kept simple, consisting of up to five frames and a maximum size of 94 by 72 pixels. The average i-mode Web page is about 1200 bytes long. So downloading an i-mode Web page takes no more than a couple of seconds.

Compact HTML example:  weather and rain information

i-mode uses Compact HTML at its application layer. Compact HTML is a subset of HTML. Compact HTML does not support JPEG images, image maps, tables, frames, backgrounds, and stylesheets. So, i-mode Web sites are kept simple. Web pages are not flashy; they are practical. They are also easy to navigate because all basic functions are performed using a combination of buttons: cursor forward, cursor backward, select, previous page and next page.

Publishing an i-mode-compatible Web site is easy. Compact HTML is a published standard. As an unspoken convention, many Web sites offering an i-mode version in addition to their standard Web site simply create an extra directory called "i" and store i-mode-compatible Web pages there.

i-mode is uniquely Japanese. It only works in Japan. Even the compact screens of cellular telephones favor Japanese text which does not require spaces between words.

For i-mode to take off outside of Japan, adaptations to the NTT proprietary technology will have to take place, and a new generation of wireless devices will have to come to market. This is not that far off.

John Michael Pierobon is an Internet consultant based in Fort Lauderdale.
John Michael may be reached by sending electronic mail to pierobon@pierobon.org

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