In February 1999, the Japanese network carrier NTT DoCoMo launched a service called “ i - mode ” as a feature that allowed mobile subscribers access to simple Web content on their mobile handsets. Rather than requiring a new markup language like HDML or WML, i - mode browsers were capable of rendering pages written in C - HTML, which was simply a subset of the HTML v3.2 language common at the time. Although publishers were encouraged to build special C - HTML sites specifically for i - mode usage, they used their existing HTML knowledge and tools, which meant there was a much smaller barrier to getting sites online. That factor resulted in a huge number of publishers doing so.
Many things contributed to i - mode (and similar rival offerings from other carriers) becoming hugely popular in Japan. One was the reliability and consistency of the browsers and the networks; another was the way in which DoCoMo provided billing mechanisms that allowed site owners to take payments from users for various commercial services. Some also suggest that the relative lack of PC - based Web access in Japan at the time also drove i - mode to success; for many consumers, their mobile device was the easiest and quickest way to access Web content at all, so i - mode adoption grew phenomenally (rising to 40 million users in a mere four years following its launch).
Whatever the reasons, i - mode and other Japanese mobile web platforms were held in high esteem by the mobile industry elsewhere in the world. Very quickly, their ubiquitous use throughout Japan became a blueprint for what a successful mobile web might look like, and several European and Asian carriers endeavored to replicate its success by using exactly the same technologies in their own networks several years later. (Notably, most of these were unsuccessful, suggesting that the i - mode technology itself was not the main factor of the Japanese network ’ s success.)
Source of Information : Wiley - Professional Mobile Web Development with WordPress Joomla and Drupal