Optimal Coded Caching under Statistical QoS Information
Emanuele Parrinello, Ayşe Ünsal, Petros Elia · 2019
The work studies the K -user shared-link broadcast channel with coded caching, where each user's file-request comes with a certain Quality-of-Service (QoS) requirement, thus allowing - in the context of multi-layered coding - users to download only those file layers that are necessary to meet their own QoS requirements. The work characterizes the exact optimal worst-case delivery time, under the assumption of uncoded cache placement that is oblivious to the individual QoS requirement of each user. The work derives a new index coding based information theoretic converse, which interestingly tells us exactly how to optimally cache.