The mobile web is structurally different

One of the premier applications on the global Internet is browsing the World Wide Web. The advent of advanced browser-enabled cell phones, high-speed wireless networks, and "unlimited-data" pricing plans is fueling the demand for Web access on mobile devices. Further, there is an increasing amount of content in the mobile Web, the set of web pages written in markup languages (CHTML, XHTML, and WML) designed specifically for consumption on mobile wireless devices. Understanding the structural properties of the WWW can be very helpful in a variety of applications, such as crawling the Web more efficiently, or performing better search results ranking. So far, however, this line of investigation has been limited to the Web consisting of HTML pages. In this study we examine the structural properties of the mobile Web graph inferred from a crawl of mobile markup pages. We find that the mobile Web graph differs in general from the fixed web in several important ways. Its connectivity is sparser than the fixed Web and its node degree distributions fall off much more rapidly. We further analyze the Web graph in terms of its bow-tie structure, which has been studied previously for the fixed web. The properties of the bow-tie structure for mobile Web are quite different from those of the fixed Web, such as having a smaller central core strongly connected component (SCC) and more disconnectedness. We also find the CHTML and XHTML/WML subgraphs of the mobile Web subgraph differ significantly, indicating the influence of different usage and maturity of the mobile Web in Japan compared to other countries. We also consider the domain-level graphs, where all nodes of a domain are collapsed into a single node and all inter- domain edges are hidden, and find notable differences between the fixed and mobile graphs. To our knowledge this is the first study of the structural properties of the web graph. We briefly comment on the potential implications of the findings, focusing on crawl as an example application.