Cache management in a mobile device

摘要

A user visiting a space is equipped with a mobile device in communication with a service system. Media items held by the service system are associated with various locations around the space and a user arriving at such a location is presented with the corresponding item or items. Preferably, these media items are pre-emptively loaded into a cache of the user's mobile device in dependence on the user's progress around the space. Items can also be flushed from cache on this basis. Instead of, or as a precursor to, flushing an item from cache to free up space, the cache space occupied by an item is reduced by degrading it.

主权项

1. A method of managing a cache of a mobile device, the cache being used for storing items associated with physical locations associated with a user; the method comprising:
(a) receiving an item at the mobile device and initially storing the received item in an un-degraded form, wherein the received item is stored in the cache of the mobile device; (b) upon a probability of usage of the received item falling below a first threshold, degrading the received item to reduce the amount of cache space needed to store the received item and storing the degraded item in the cache instead of the un-degraded item, wherein said probability of usage of the received item is at least partially assessed from a determination of a probability of a feature associated with the item being visited, and wherein said probability of the feature being visited is at least partially assessed from a distance of said feature from said physical locations associated with said user; (c) upon the received item being required for presentation to the user, retrieving the received item from cache and presenting it to the user; (d) determining whether the received item is in a degraded form, this step being carried out before, at the same time as, or after the receiving step (c); (e) where the determining step (d) indicates that the item is in a degraded form, requesting an un-degrading form of the received item for the degraded form of the received item being presented to the user; and (f) upon the probability of usage of the received item falling below a second threshold, flushing the received item from the cache.