Availability formulations for segment protection

Segment Protection (SP) is an efficient scheme for protection in WDM optical networks. This letter provides algebraic formulations to evaluate SP availability both in the dedicated and shared backup case. The availability models are applied to numerical examples and significant relations between SP availability and relevant connection parameters are identified.

I. Introduction

Thanks to the wavelength-division-multiplexing (WDM) technology, today's optical networks provide a transport infrastructure with very high capacity. This huge capacity requires efficient survivability mechanisms in order to avoid that the failure of a network element (typically a link or a node) can cause a large amount of data loss. Recently, new techniques have been proposed to efficiently deal with this problem in mesh networks. Among them, Segment Protection (SP) is a promising candidate for protection in WDM/MPLS networks because of its desirable resource efficiency, and for its ability to limit the signalling delay for recovery.