Threshold based selective survivability for optical WDM mesh networks

This paper presents survivability mechanisms that attempt to improve the overall restoration efficiency of dynamic link restoration in optical WDM mesh networks. The proposed mechanisms make use of network state information such as link load in order to identify critical network sections (such as links or segments) that are subsequently protected by selectively assigning backup capacity ahead of failures. The first approach, termed "threshold based selective link restoration", utilizes existing link load information to identify critical links, and the second approach, termed "threshold based selective segment restoration", employs data-analysis techniques to identify critical segments. The overall goal of the proposed algorithms is to improve the restoration efficiency by providing a trade-off between proactive protection and reactive restoration. The experimental results indicate that under high loads, the proposed approaches maintain a consistent restoration efficiency that is at least 10% when compared to dynamic restoration.