On the Fundamental Limit of Coded Caching Systems with a Single Demand Type Caching is a technique to reduce the communication load in peak hours by prefetching contents during offpeak hours. Recently MaddahAli and Niesen introduced an information theoretic framework for coded caching, and showed that significant improvement can be obtained compared to uncoded caching. Considerable efforts have been devoted to identify the precise information theoretic fundamental limit of such systems, however the difficulty of this task has also become clear. One of the reasons for this difficulty is that the original coded caching setting allows multiple demand types during delivery, which in fact introduces tension in the coding strategy to accommodate all of them. In this paper, we seek to develop a better understanding of the fundamental limit of coded caching by investigating single demand type systems. We first show that in the canonical threeuser threefile systems, such single demand type systems already provide important insights. Motivated by these findings, we focus on systems where the number of users and the number of files are the same, and the demand type is when all files are being requested. A novel coding scheme is proposed, which provides several optimal memorytransmission operating points. Outer bounds for this class of systems are also considered, and their relation with existing bounds is discussed.

Multiaccess coded caching: gains beyond cacheredundancy The work considers the Kuser cacheaided shared link broadcast channel where each user has access to exactly z caches of normalized size xcexb3, and where each cache assists exactly z users. For this setting, for two opposing memory regimes, we propose novel caching and coded delivery schemes which maximize the local caching gain, and achieve a coding gain larger than  1Kgamma (users served at a time) despite the fact that the total cache redundancy remains  Kgamma irrespective of z. Interestingly, when z  fracK1Kgamma, the derived optimal coding gain is Kgamma z1, matching the performance of a hypothetical scenario where each user has its own dedicated cache of size zgamma.