New bounds on the (n, k, d) storage systems with exact repair

Soheil Mohajer, Ravi Tandon

Research output: Chapter in Book/Report/Conference proceedingConference contribution

20 Scopus citations


The exact-repair problem for distributed storage systems is considered. Characterizing the optimal storage-vs-repair bandwidth tradeoff for such systems remains an open problem for more than four storage nodes. A new family of information theoretic bounds is provided for the storage-vs-repair bandwidth tradeoff for all (n, k, d) systems. The proposed bound readily recovers Tian's result for the (4, 3, 3) system, and hence suffices for exact characterization for this system. In addition, the bound improves upon the existing bounds for the (5, 4, 4) system. More generally, it is shown that this bound characterizes the optimal boundary of the exact repair tradeoff for all distributed storage systems, with (n, k, d) = (n, n-1; n-1) when β ≤ 2α/k.

Original languageEnglish (US)
Title of host publicationProceedings - 2015 IEEE International Symposium on Information Theory, ISIT 2015
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages5
ISBN (Electronic)9781467377041
StatePublished - Sep 28 2015
Externally publishedYes
EventIEEE International Symposium on Information Theory, ISIT 2015 - Hong Kong, Hong Kong
Duration: Jun 14 2015Jun 19 2015

Publication series

NameIEEE International Symposium on Information Theory - Proceedings
ISSN (Print)2157-8095


OtherIEEE International Symposium on Information Theory, ISIT 2015
Country/TerritoryHong Kong
CityHong Kong


  • Distributed storage system
  • Exact repair
  • New outer bounds

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Information Systems
  • Modeling and Simulation
  • Applied Mathematics

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