  Cellular networks are facing severe traffic overloads due to the
proliferation of smart handheld devices and traffic-hungry applications. A
cost-effective and practical solution is to offload cellular data through WiFi.
Recent theoretical and experimental studies show that a scheme, referred to as
delayed WiFi offloading, can significantly save the cellular capacity by
delaying users' data and exploiting mobility and thus increasing chance of
meeting WiFi APs (Access Points). Despite a huge potential of WiFi offloading
in alleviating mobile data explosion, its success largely depends on the
economic incentives provided to users and operators to deploy and use delayed
offloading. In this paper, we study how much economic benefits can be generated
due to delayed WiFi offloading, by modeling a market based on a two-stage
sequential game between a monopoly provider and users. We also provide
extensive numerical results computed using a set of parameters from the real
traces and Cisco's projection of traffic statistics in year 2015. In both
analytical and numerical results, we model a variety of practical scenarios and
control knobs in terms of traffic demand and willingness to pay of users,
spatio-temporal dependence of pricing and traffic, and diverse pricing and
delay tolerance. We demonstrate that delayed WiFi offloading has considerable
economic benefits, where the increase ranges from 21% to 152% in the provider's
revenue, and from 73% to 319% in the users' surplus, compared to on-the-spot
WiFi offloading.
