This article presents an overview of planning problems that arise in the design and dimensioning of survivable telecommunications networks using the Synchronous Digital Hierarchy (SDH) or Synchronous Optical Network (SONET) transmission standards. SDH/SONET principles and the two main strategies for network survivability are described, i.e. restoration (design of a reserve network) and protection (in particular, the design of multiple self-healing rings networks). Then an extensive synthesis of the related litterature covering these problems is presented and future challenges are discussed.
Published November 1998 , 26 pages