Photon Netw Commun DOI 10.1007/s11107-017-0721-0 ORIGINAL PAPER An online cost-efficient protection scheme for quick recovery in all-optical WDM mesh networks Vishal Dey 1 · Monish Chatterjee 2 · Saptarashmi Bandyopadhyay 1 · Uma Bhattacharya 1 Received: 20 September 2016 / Accepted: 20 June 2017 © Springer Science+Business Media, LLC 2017 Abstract Since a single fiber carries a huge amount of data in optical WDM networks, a fiber cut even for a brief period is a very serious event. Designing schemes to prevent dis- ruption of user traffic and recovery techniques from failures is thus an important area of research. Since a single fiber cut is the most common type of fault, in this paper we address the problem of protecting all-optical WDM mesh networks from single link failure. Our proposed online pro- tection scheme is an improvement over an existing approach and is not only cost-efficient in terms of network resource consumption but can also provide quick recovery from a link failure. We first provide an ILP formulation for the problem and then propose a heuristic solution iStreams that can pro- vide near-optimal solution in polynomial time. Performance comparisons with some well-known schemes of protection show that our heuristic algorithm can be a better choice for conserving resource while providing quick recovery from a link failure. Keywords WDM · All-optical networks · Link failure · Protection scheme · Cost-efficient · Quick recovery B Monish Chatterjee monish_chatterjee@yahoo.com Vishal Dey vishal.iiestcst@gmail.com Saptarashmi Bandyopadhyay saptarashmicse@gmail.com Uma Bhattacharya ub@cs.iiests.ac.in 1 Department of Computer Science and Technology, Indian Institute of Engineering Science and Technology, Shibpur, India 2 Department of Computer Science and Engineering, Asansol Engineering College, Asansol, India 1 Introduction As the traffic over the Internet is growing exponentially every year, a single fiber in optical WDM networks that form the Internet backbone will carry huge amount of data. The dis- ruption of this traffic due to a fiber failure even for a brief period is indeed a serious affair. Thus designing survivabil- ity schemes to protect traffic disruption due to fiber failures will remain one of the most important areas of research [1]. Since a fiber cut is the most commonly occurring fault in optical networks, most works on fault have addressed the problem of surviving from a single link failure [1]. In order to accommodate the rapidly growing traffic, network resources have become scarce and so it has become neces- sary that reliable networks be designed in a cost-efficient way. All-optical or transparent networks offer many advan- tages over their optically opaque counterparts. One important advantage is faster switching due to the absence of electronic and photonic processing delays that can act as a bottleneck on the transmission time. All-optical networks, however, expe- rience higher blocking probability than the opaque ones due to the absence of wavelength conversion. They also have lim- itations in signaling capabilities and complete performance monitoring [2]. Any survivability scheme for all-optical net- works must then address these critical limitations and be designed in a way to consume as fewer resources as pos- sible. However, survivability schemes that are best in terms of resource conservation do not take into account the time required to recover from a failure, which can be substantial. Thus it is important to design robust schemes for survivabil- ity considering the trade-offs between recovery speed, data loss, capacity requirements and time complexity. Two schemes generally used for addressing the problem of survivability from a link failure in optical WDM networks are 123