Caching reverse-geocoded locations on smartphones

Photo-driven smartphone usage often requires invoking a server to perform reverse-geocoded location lookup, an approach that incurs network delay and increased power consumption for communication. A solution we consider is to cache the reverse-geocoding results so that the location of subsequent photos taken within some range of previously reverse-geocoded photos can be looked up in the cache without having to access a server. The key challenge, then, is effectively defining and caching the reverse-geocoded regions on the smartphone to enable accurate lookups. We propose three schemes and evaluate their performance over a photo data set taken across 14 cities.