It has been recently advocated that in large communication systems it is benecial both for the users and for the network as a whole to store content closer to users. One particular implementation of such an approach is to co-locate caches with wireless base stations. In this paper we study geographically distributed caching of a xed collection of les. We model cache placement with the help of stochastic geometry and optimize the allocation of storage capacity among les in order to minimize the cache miss probability. We consider both per cache capacity constraints as well as an average capacity constraint over all caches. The case of per cache capacity constraints can be eciently solved using dynamic programming, whereas the case of the average constraint leads to a convex optimization problem. We demonstrate that the average constraint leads to signicantly smaller cache miss probability. Finally, we suggest a simple LRU-based policy for geographically distributed caching and show that its performance is close to the optimal.
['Konstantin Avrachenkov', 'Xinwei Bai', 'Jasper Goseling']
Optimization of Caching Devices with Geometric Constraints