Optimal Error Correcting Delivery Scheme for Coded Caching with Symmetric Batch Prefetching

Abstract

Coded caching is used to reduce network congestion during peak hours. A single server is connected to a set of users through a shared bottleneck link, which generally is assumed to be error-free. During non-peak hours, all the users have full access to the files and they fill their local cache with portions of the files available. During delivery phase, each user requests a file and the server delivers coded transmissions to meet the demands taking into consideration their cache contents. In this paper we assume that the link between the server and the users is error prone. A new delivery scheme is required to meet the demands of each user even after receiving finite number of transmissions in error. We characterize the average rate and peak rate for this problem. We find closed form expressions of these rates for a particular caching scheme namely symmetric batch prefetching. We also propose an optimal linear error correcting delivery scheme for coded caching problems with symmetric batch prefetching.