Service provisioning with ad-hoc deployed high-speed access points in urban environments

Exploiting user-deployed networks as part of a public infrastructure has been proposed as a concept to radically lower the cost of provisioning access and services in urban environments. An important question is how dense a network with spotty coverage has to be in order to support interesting services. In this paper, we introduce a framework for evaluating the user-perceived performance for two service types, a time-critical news subscription service (involving streaming) and a more delay tolerant entertainment service ("Web browsing"). The user terminals contain a memory cache and an "agent" that opportunistically downloads and stores relevant pieces of information as users walk close to the access points. Results show that above a critical access point density, that is still significantly lower than the one required for continuous coverage, the services start performing very well with little or no outdated information. In most studied scenarios, we are communication limited meaning that memory capacity is not a problem, but energy is