Multi-link cache data retrieval for delivery phase in ultra dense small cell networks

Smart user association methods can have tremendous advantages when it comes to caching. It is anticipated that, in future, small cell deployment will be such that there will be at least one small cell for every user. This comes with a great advantage of maximizing the hit probability for cache-enabled networks. In this work, we investigate a multi-link user association model for Ultra Dense Networks (UDN) in which a user associates with multiple caching entities to retrieve its requested content. The user has a chance to search for the requested file at multiple locations, which will increase the chances of getting the request fulfilled, subsequently increasing the cache hit ratio of the user. We let the user select its preferences based on the received SINR from the available caches and leverage the basic user association methods to fully exploit the resources available to the user. Consequently, we derive analytical expressions to study the data rate and achieved cache hit ratio by the proposed method. Through simulation results, we illustrate that the performance of our proposed multi-link cache data retrieval method is distinctively different from present schemes and shed new insight on serving users in a cache-enabled UDN.