WebCompanion: a friendly client-side Web prefetching agent

Accessing remote sites of the World Wide Web is often a frustrating experience for users because of long Web page retrieval times even over relatively fast Internet connections. Users are more likely to embrace the further expansion of the role of the Web into a major infrastructure for electronic commerce and for information, application, and multimedia delivery if Web accesses can be accelerated. One technique that attempts this is prefetching. We built a client-side Java-implemented prefetching agent, WebCompanion, which employs a novel adaptive, fast, and selective online prefetching strategy based on estimated round-trip times for Web resources. This strategy efficiently hides the access latencies for slow resources while at the same time limiting the network and server overhead and local resource consumption to moderate levels. Our extensive experiments show an average access speedup of greater than 50 percent and an average network byte overhead of less than 150 percent using WebCompanion over a fast Internet connection. We measured a slight acceleration in accessing the Web through WebCompanion even in a pessimistic scenario where the user never requests a prefetched document.