The Web is rapidly increasing its reach beyond the desktop to devices ranging from mobile phones to domestic appliances. In such a heterogeneous client environment, the content adaptation to meet diverse device capabilities is becoming a major requirement for the future Web. Although a variety of approaches to the content adaptation has been researched, an intermediary-based transcoding infrastructure is regarded as a reasonable and appropriate solution to the content transcoding. Also, it is known that a transcoding proxy can improve its performance by caching transcoding results, because repeated transcoding task could be eliminated. Researchers applied a traditional Web cache to a transcoding proxy by modifying it to cache multiple versions of the same Web contents for diverse client capabilities.
Recently, cooperative transcoding proxy architecture is proposed to improve the system performance and address the scalability problem of a stand-alone transcoding proxy. This research adopted traditional cooperation mechanism (i.e. query-based discovery) to discover an object in a remote proxy. However, several problems occur in this architecture since the traditional mechanism for a single-version environment is applied to a multiple-version environment. Therefore, we propose alternative cooperative transcoding proxy architecture using a version clustering and content-aware caching, a content-aware transcoding request distribution, and a request redirection.