Coded caching in a multi-server system with random topology
File(s)MGL_TCOM20.pdf (622.33 KB)
Accepted version
Author(s)
Mital, Nitish
Gunduz, Deniz
Ling, Cong
Type
Journal Article
Abstract
Cache-aided content delivery is studied in a multi-server system with P servers and K users, each equipped with a local cache memory. In the delivery phase, each user connects randomly to any ρ out of P servers. Thanks to the availability of multiple servers, which model small-cell base stations (SBSs), demands can be satisfied with reduced storage capacity at each server and reduced delivery rate per server; however, this also leads to reduced multicasting opportunities compared to the single-server scenario. A joint storage and proactive caching scheme is proposed, which exploits coded storage across the servers, uncoded cache placement at the users, and coded delivery. The delivery latency is studied for both successive and parallel transmissions from the servers. It is shown that, with successive transmissions the achievable average delivery latency is comparable to the one achieved in the single-server scenario, while the gap between the two depends on ρ, the available redundancy across the servers, and can be reduced by increasing the storage capacity at the SBSs. The optimality of the proposed scheme with uncoded cache placement and MDS-coded server storage is also proved for successive transmissions.
Date Issued
2020-08-01
Date Acceptance
2020-04-01
Citation
IEEE Transactions on Communications, 2020, 68 (8), pp.4620-4631
ISSN
0090-6778
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Start Page
4620
End Page
4631
Journal / Book Title
IEEE Transactions on Communications
Volume
68
Issue
8
Copyright Statement
© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Sponsor
Commission of the European Communities
Commission of the European Communities
Identifier
https://ieeexplore.ieee.org/document/9082622
Grant Number
677854
675891
Subjects
0804 Data Format
0906 Electrical and Electronic Engineering
1005 Communications Technologies
Publication Status
Published
Date Publish Online
2020-04-30