OptiComm: Optical Networking and Communications Conference最新文献

{"title":"Fiber span failure protection in mesh optical networks","authors":"Guangzhi Li, R. Doverspike, C. Kalmanek","doi":"10.1117/12.436053","DOIUrl":"https://doi.org/10.1117/12.436053","url":null,"abstract":"A major challenge of optical network design is deciding where spare capacity is needed and how much, so that interrupted traffic may be rerouted in the event of a failure. Given the optical network topology and traffic forecast, the network design needs to map the traffic forecast into optical connection demands. For each optical connection demand, two paths need to be computed, i.e., a service path and a restoration path. In most cases, optical network design mainly considers single failure. If two service paths do not share any single failure, their restoration paths can share the same capacity on any links that they have in common. In this way, the total spare capacity needed for restoration can be dramatically reduced. However, due to the layered architecture in optical networks, a pair of diverse paths in a particular layer won't necessarily be diverse when the lower layer topology is considered. For example, optical networks are typically built on top of a network of fiber spans. A single span cut in the fiber network can cause multiple link failures in the optical layer. In this paper, we investigate fiber span failure protection scenarios in mesh optical networks. Specifically, we provide an algorithm to find two fiber span disjoint paths for each demand, such that the total spare capacity allocated in the network is minimized. Another problem that arises in restoration path computation is the existence of a trap topology. In a trap topology, the pre- selected service path may not have a diverse restoration path even though two diverse paths exist in the network. For simple link-disjoint protection, the min-cost max-flow algorithm can be used to avoid this problem. For fiber span failure protection, the trap topology problem becomes complicated. We show that it is NP-hard problem to find the maximum number of fiber-span disjoint paths between two nodes. We provide two heuristic algorithms to solve this trap topology problem. We have implemented fiber span failure protection in our restoration capacity planning toolkit Cplan. We describe an application of fiber span failure protection at the end of the paper.","PeriodicalId":187370,"journal":{"name":"OptiComm: Optical Networking and Communications Conference","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115509185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Routing differentiated reliable connections in single- and multifiber WDM optical networks","authors":"C. Saradhi, C. Murthy","doi":"10.1117/12.436063","DOIUrl":"https://doi.org/10.1117/12.436063","url":null,"abstract":"Wavelength division multiplexing (WDM) networks are matured to provide, scalable data centric infrastructure, capable of delivering flexible, value added, high speed and high bandwidth services directly from the optical (WDM) layer. Different applications/end users need different levels of fault tolerance and differ in how much they are willing to pay for the service they get. The current optical networks are capable of providing either full protection in presence of single failure or no protection at all. So, there is a need for a way of providing the requested level of fault tolerance (reliability) to different applications/end users. We choose the reliability of a connection as a parameter to denote the different levels of fault tolerance. In this paper, we consider the problem of dynamically establishing reliable connections (R-connections) in wavelength routed WDM optical networks. We develop an efficient algorithm to select routes and wavelengths to establish an R-connection with a specified reliability guarantee, in a resource efficient manner, using primary-backup approach. In our scheme, we provide partial backup lightpaths for varying lengths of the primary lightpath to enhance the reliability of the connection. The length of the primary lightpath for which the backup lightpath is provided depends on the reliability required by the application/end user but not on the actual length of the primary lightpath, network topology, and design constraints. We present the initial experimental results which suggest that our scheme is attractive enough in terms of resource utilization and average call acceptance ratio.","PeriodicalId":187370,"journal":{"name":"OptiComm: Optical Networking and Communications Conference","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125873116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quality of protection (QoP): a quantitative unifying paradigm to protection service grades","authors":"O. Gerstel, G. Sasaki","doi":"10.1117/12.436060","DOIUrl":"https://doi.org/10.1117/12.436060","url":null,"abstract":"In this paper we discuss a quantitative framework for best- effort protection of the optical layer. This framework provides a way to bridge the gap between two known protection grades of fully protected connections vis-a-vis unprotected protection. The framework allows to specify the probability with which the connection will be protected, providing the customer with a full range of protection guarantees at possibly different prices. Since connections may be partially protected, the required protection bandwidth can be reduced. The amount of protection bandwidth is shown to depend on an 'equivalent survivable bandwidth.' The framework also extends to preemptable (low priority) connections and to different ring architectures.","PeriodicalId":187370,"journal":{"name":"OptiComm: Optical Networking and Communications Conference","volume":"4599 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129936968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simple and intelligent routing and wavelength assignment algorithm for all-optical networks","authors":"Ding Zhemin, M. Hamdi","doi":"10.1117/12.436061","DOIUrl":"https://doi.org/10.1117/12.436061","url":null,"abstract":"In this paper we consider the routing and wavelength assignment problem in a wavelength routed all optical network. Inspired by techniques from artificial intelligence, in particular the Blocking Island (BI) abstraction, we propose a simple and intelligent routing and wavelength assignment (RWA) algorithm: BI_RWA. This algorithm can be used in arbitrarily connected optical networks. In addition, it is general enough such that with some simple modifications, it can be applied to different optical networking scenarios: static or dynamic traffic, single or multiple fiber links between node pairs, with or without wavelength converters. We have conducted simulation experiments to evaluate the performance of our algorithm. The simulation is carried out in two parts: static traffic and dynamic traffic. The results will demonstrate that our RWA algorithm outperforms state-of-the-art related algorithms.","PeriodicalId":187370,"journal":{"name":"OptiComm: Optical Networking and Communications Conference","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134045418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lightpath merging mechanism for improving connectivity in MPλS networks","authors":"Seung-Joon Seok, Dongeun Suh, C. Kang, Gwan-Jung Kim, Jaesup Lee","doi":"10.1117/12.436066","DOIUrl":"https://doi.org/10.1117/12.436066","url":null,"abstract":"Recently, it is expected by a number of engineers that an intelligent optical network will be used for transport network of Internet. A MP(Lambda) S (Multiprotocol Lambda Switching), that is based on both wavelength routing technology and MPLS control plane protocols, is an approach IETF proposed for intelligent optical network. In this article, we propose a network architecture for the MP(lambda) S network, called an Integrated MPLS network. This article also applies a merging mechanism to MP(lambda) S network to improve connectivity, likely MPLS. The Merging mechanism can reduce the number of labels requested and blocking probability for label requests. However, wavelengths, unlikely electrical label, cannot be merged at optical level. To solve this problem, we define a merging module that interleaves two different data streams at electrical level. In addition, we examine the routing problem of the proposed MP(Lambda) S network and propose a graph model for solving this problem, simply. For evaluation of the proposed mechanism, we use simulation mode. The simulation results show that the merging mechanism may offer significant improvement of network performance.","PeriodicalId":187370,"journal":{"name":"OptiComm: Optical Networking and Communications Conference","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131851043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scheduling problems with applications to packet-switched optical WDM networks","authors":"E. Bampis, G. Rouskas","doi":"10.1117/12.436056","DOIUrl":"https://doi.org/10.1117/12.436056","url":null,"abstract":"We consider a scheduling problem, which we call the Scheduling and Wavelength Assignment (SWA) problem, arising in optical networks that are based on the Wavelength Division Multiplexing (WDM) technology. We prove that the SWA problem is (Nu) (Rho) -hard for both the preemptive and the non- preemptive cases. Furthermore, we propose two efficient approximation algorithms. The first is for the preemptive case and it is based on a natural decomposition of the problem to the classical multiprocessor scheduling and open-shop problems. For the non-preemptive case, we prove that a naive implementation of list scheduling produces a schedule that can be m times far from the optimum, where m is the number of processors (equivalently, WDM channels). Finally, we give a more refined version of list scheduling and we prove it to be a 2-approximation algorithm for both the off-line and the on- line contexts.","PeriodicalId":187370,"journal":{"name":"OptiComm: Optical Networking and Communications Conference","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128444491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IP-over-WDM dynamic link layer: challenges, open issues, and comparison of files-over-lightpaths versus photonic packet switching","authors":"M. Izal, Javier Aracil Rico","doi":"10.1117/12.436068","DOIUrl":"https://doi.org/10.1117/12.436068","url":null,"abstract":"This paper addresses the suitability of WDM coarse packet switching solutions for IP traffic. Our findings show that the combination of traffic grooming at the higher layers and coarse packet switching at the optical layer provides at least the same performance as more sophisticated and difficult to realize photonic packet switching solutions. We propose a network architecture named files-over-lightpaths that not only simplifies the network optical and electronic design by making use of coarse packet switching, but also serves to the purpose of decreasing the TCP transaction latency in comparison to a flat or split Internet organization with fine grain photonic packet switching.","PeriodicalId":187370,"journal":{"name":"OptiComm: Optical Networking and Communications Conference","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132701709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Incremental capacity dimensioning for reliable IP-over-WDM networks","authors":"S. Arakawa, M. Murata","doi":"10.1117/12.436055","DOIUrl":"https://doi.org/10.1117/12.436055","url":null,"abstract":"In order to construct a reliable IP over WDM network, backup paths as well as primary paths should be embedded within a wavelength-routed topology (or logical topology). However, many conventional approaches assume that the traffic demand is known a priori. In this paper, we propose a new approach, called an incremental capacity dimensioning approach, to build the logical topology. Our incremental approach consists of three steps for designing the logical topology: an initial phase, an incremental phase, and a readjustment phase. By our approach, the logical topology can be adjusted according to the incrementally changing traffic demand. During the incremental phase, the backup lightpaths are reconfigured when the new primary path is set up since the backup lightpaths do not affect the carried traffic on the primary paths. Our proposed algorithm, called MRB (Minimum Reconfiguring for Backup lightpath), assigns the wavelength route in such a way that the number of backup lightpaths to be reconfigured is minimized. Then, the backup lightpaths are actually reconfigured. For this purpose, we also formulate an optimality problem for reconfiguring the backup lightpaths. Our results show the total traffic volume which the IP over WDM network can accommodate is improved by using our MRB algorithm.","PeriodicalId":187370,"journal":{"name":"OptiComm: Optical Networking and Communications Conference","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114394303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal multicast in DWDM networks: minimizing wavelength conversion","authors":"M. MacGregor","doi":"10.1117/12.436058","DOIUrl":"https://doi.org/10.1117/12.436058","url":null,"abstract":"The problem of assigning wavelengths and routing multicast sessions in DWDM networks has given rise to a host of heuristic and approximate techniques. In this paper we demonstrate that it is feasible to find optimal solutions for many instances of this problem using integer linear programming. The technique presented is also useful as an optimal standard to which heuristics can be compared in order to determine the quality of solutions they generate. The goal of this paper is to document an integer programming tableau for routing multicast sessions in DWDM networks, while accounting for a variety of limits on the abilities of the nodes in the network to drop, split and convert wavelengths. Examples of applying the tableau to problems of moderate size are included.","PeriodicalId":187370,"journal":{"name":"OptiComm: Optical Networking and Communications Conference","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128251337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced route assignment mechanism in optical control plane","authors":"C. Xin, Y. Ye, S. Dixit, C. Qiao","doi":"10.1117/12.436050","DOIUrl":"https://doi.org/10.1117/12.436050","url":null,"abstract":"No doubt, there is a need to introduce intelligence into the control plane of the optical network to provide dynamic and real-time provisioning and effective survivability. However, the traffic pattern migration from static to dynamic gives rise to many challenging issues. One such issue is the route assignment. For static traffic, the route assignment can generally be optimized using a variety of offline algorithms. For dynamic traffic, however, such a global optimization is impossible. Nevertheless, it is possible to perform individual optimization for each new call in the dynamic traffic pattern. In this paper, we propose an enhanced route assignment mechanism for the optical control plane and evaluate its performance benefits.","PeriodicalId":187370,"journal":{"name":"OptiComm: Optical Networking and Communications Conference","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121827260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}