Home > Articles > Networking > Wireless/High Speed/Optical

  • Print
  • + Share This
This chapter is from the book

This chapter is from the book

Memory and Cache Size

A huge consideration for developing i-mode sites is the fact that the handset of your users will have a small memory and cache size. This means that your page size will have to be small enough to fit into that space, and that will be one of the primary objectives for optimizing your site.

So just how small is the built-in memory and cache of a typical i-mode device? Well, like so many other things in this article, that answer varies based upon the individual handset. DoCoMo's i-mode handsets all send information about the browser (the user agent) to your Webserver in the form of a string like the following:


This translates to:

DoCoMo/HTTP version/handset model/cache size

The first generation of i-mode handsets were limited to 5KB, and do not include the information about cache. For instance:


Later i-mode terminals had an option to expand the volume of data that could be used for pages by increasing the size of the cache. When an i-mode handset is accessing your server with an increased cache, it is indicated through the addition of the cache information. For example:


The lowercase "c" signifies that the terminal is using an increased cache, and the value that follows is the maximum cache size allocated for data download for one page—which includes both text and images.

If the same type of handset does not have the increased cache turned on, no information about the cache will be sent, and the download limit will be the default 5KB for that device. For instance:


Pages that are too large will cause an error message in the i-mode terminal, and the content will be truncated at the download limit for that device.

  • + Share This
  • 🔖 Save To Your Account