Programming WebLogic Server for Wireless Services
i-Mode is currently a proprietary, closed specification, developed and deployed by NTT DoCoMo of Japan, that allows for the development of Internet and Web-based services for mobile phones and other wireless digital devices. The only i-Mode implementation is DoCoMo's mobile internet access system, although several telecommunication companies in Europe and the United States have expressed an interest in i-Mode.
The i-Mode specification addresses the limitations of wireless networks (low bandwidth, high latency, and unpredictable availability and stability) and wireless devices (limited CPU, memory, and battery life, and a simple user interface). It specifies two essential elements of wireless communication: an over-the-air wireless protocol and a markup language.
i-Mode gateways form the connection between clients on the wireless network and applications hosted on application servers on the Internet. The i-Mode gateway builds a bridge between the telecommunication and computer networks by routing requests from wireless clients to the application servers.
i-Mode applications use the compact Hypertext Markup Language (cHTML), which is specifically designed to interface with the microbrowsers in i-Mode-enabled devices. cHTML is a subset of HTML, with a number of extensions for the mobile phone environment. The NTT DoCoMo (English) Supported Tags and Specs defines the tags and structure of a cHTML document.
When a wireless client sends a request to an i-Mode application running on WebLogic Server, the request is first routed through the i-Mode gateway and then forwarded to the appropriate URL. The response is then re-routed back through the gateway, translated to i-Mode, and forward to the wireless client. This proxy architecture allows application developers to build services that are network and terminal independent.