Waveband Grooming Research Articles

Survivable waveband grooming in multi-domain optical networks

Since the size of traffic demands ranges from sub-wavelength-level to wavelength-level, traffic demands need to be aggregated and carried over the network in a cost effective manner to make sure that the resources can be utilized effectively. Therefore, the technique called waveband grooming is proposed to save the cost and to reduce the number of switching ports in Optical-Cross Connects (OXCs). However, the existing waveband grooming algorithms are mostly limited to single-domain optical networks and also do not consider the survivability. The current optical backbones keeps enlarging, and the backbones are actually divided into multiple independent domains to provide the needed scalability and the confidentiality. It is necessary to study the survivable waveband grooming in multi-domain optical networks. In this paper, we propose two new heuristic algorithms called Intra-domain Sub-path Survivable Grooming (ISSG) algorithm and Inter-domain End-to-end Survivable Grooming (IESG) algorithm, respectively. In ISSG, we allocate an end-to-end inter-domain working path for each demand and then calculate a link-disjoint backup sub-path for each intra-domain working sub-path. In IESG, we allocate two link-disjoint end-to-end inter-domain paths for each demand, one is working path and the other one is backup path. Simulation results show that ISSG and IESG have similar trend with different parameters. In addition, IESG has lower blocking probability while ISSG has lower average port-cost.

Survivable integrated grooming in multi-granularity optical networks

Survivability is an important issue to ensure the service continuity in optical network. At the same time, with the granularity of traffic demands ranging from sub-wavelength-level to wavelength-level, traffic demands need to be aggregated and carried over the network in order to utilize resources effectively. Therefore, multi-granularity grooming is proposed to save the cost and reduce the number of switching ports in Optical-Cross Connects (OXCs). However, current works mostly addressed the survivable wavelength or waveband grooming. Therefore, in this paper, we propose three heuristic algorithms called Multi-granularity Dedicated Protection Grooming (MDPG), Multi-granularity Shared Protection Grooming (MSPG) and Multi-granularity Mixed Protection Grooming (MMPG), respectively. All of them are performed based on the Survivable Multi-granularity Integrated Auxiliary Graph (SMIAG) that includes one Wavelength Integrated Auxiliary Graph (WIAG) for wavelength protection and one waveBand Integrated Auxiliary Graph (BIAG) for waveband protection. Numerical results show that MMPG has the lowest average port-cost, the best resource utilization ratio and the lowest blocking probability among these three algorithms. Compared with MDPG, MSPG has lower average port-cost, better resource utilization ratio and lower blocking probability.

Multicast multi-granular grooming based on integrated auxiliary grooming graph in optical networks

In order to improve the bandwidth utilization efficiency and reduce the blocking probability for multicast requests in optical networks, the multicast traffic grooming approach was proposed to groom a lot of low-speed traffic to a few of high-speed light-trees. At the same time, in order to save the ports and the cost of optical cross-connect, the multicast waveband grooming approach was proposed to groom multiple light-trees to a few of waveband tunnels. However, the existing approaches all did not consider the joint performances of improving bandwidth utilization efficiency, reducing blocking probability and saving ports for multicast requests. Therefore, in this article, we propose a new multicast multi-granular grooming approach to perform the hierarchical sequential grooming to improve the joint performances based on a newly developed integrated auxiliary grooming graph (IAGG) that includes multiple wavelength integrated grooming graphs (WIGGs) and one waveband virtual topology layered graph (BVLG) to support both the multicast traffic grooming and multicast waveband grooming. In order to achieve the map of light-tree to the virtual topology layer in WIGG or BVLG, we present a light-segment map method, where a light-tree will be divided to several light-segments each of which will be independently mapped to the virtual topology layer. Since different definitions of blocking probability may lead to different objectives, we define two kinds of blocking probability, mean blocking probability of requests (MBPR) and mean blocking probability of users (MBPU). According to the two definitions of blocking probability, we propose two multicast multi-granular grooming heuristic algorithms, Heuristic Algorithm with minimizing MBPR and Heuristic Algorithm with minimizing MBPU based on IAGG. Simulation results show that the two proposed algorithms are both efficient and have better performances than traditional multicast grooming algorithm.

Multicast Grooming Algorithms in Waveband Switching Multi-Domain Optical Networks

In this paper, we study the multicast waveband grooming in multi-domain optical networks and propose three heuristic algorithms, Per-Domain Multicast Grooming (PDMG), Virtual Topology Multicast Grooming (VTMG) and Hierarchical Multi-domain Multicast Grooming (HMMG). Simulation results show that, comparing with PDMG and VTMG, HMMG has the best performance of ports savings and the lowest blocking probability.

Multi-cast waveband grooming algorithms in multi-domain optical networks

With the increasing of number of multimedia network applications, multi-cast services are becoming more and more popular. At the same time, the waveband switching technique is proposed to save ports and to reduce the cost of optical cross-connect. However, the existing multi-cast waveband grooming algorithms are mostly limited to single-domain optical networks. The size of optical backbones keeps enlarging, and the backbones are actually divided into multiple independent domains to provide the needed scalability and confidentiality. To solve these problems, the authors propose three heuristic algorithms: per-domain multi-cast grooming (PDMG), virtual topology multi-cast grooming (VTMG) and hierarchical multi-domain multi-cast grooming (HMMG). The main difference between these algorithms is that the inter-domain routing is performed in a different manner; in other words, the routings in PDMG, VTMG and HMMG are computed based on the domain-by-domain fixed routing table, the high layer in the aggregative virtual topology of multi-domains and the hierarchical integrated multi-cast auxiliary graph, respectively. For the intra-domain routing, the three algorithms employ the same method based on an intra-domain multi-cast integrated auxiliary graph. Simulation results show that compared with PDMG and VTMG, HMMG has the best performance in terms of the number of ports saved and the blocking probability.

基于组播树的多粒度波带静态疏导算法

基于组播树的多粒度波带静态疏导算法

Performance analysis of an optical network employing waveband and traffic grooming

This paper analyses an optical network architecture composed by an arrangement of nodes equipped with multi-granular optical cross-connects (MG-OXCs) in addition to the usual optical cross-connects (OXCs). Then, selected network nodes can perform both waveband as well as traffic grooming operations and our goal is to assess the improvement on network performance brought by these additional capabilities. Specifically, the influence of the MG-OXC multi-granularity on the blocking probability is evaluated for 16 classes of service over a network based on the NSFNet topology. A mechanism of fairness in bandwidth capacity is also added to the connection admission control to manage the blocking probabilities of all kind of bandwidth requirements. Comprehensive computational simulation are carried out to compare eight distinct node architectures, showing that an adequate combination of waveband and single-wavelength ports of the MG-OXCs and OXCs allow a more efficient operation of a WDM optical network carrying multi-rate traffic.

Dynamic waveband grooming based on hierarchical integrated grooming auxiliary graph in multi-domain mesh optical networks

With the number of wavelengths in fibers increasing, the number of optical switching ports in conventional Optical Cross-Connect (OXC) keeps enhancing, so that waveband grooming technique is proposed to save the switching ports in OXC. Most of previous works focused on waveband grooming in single-domain optical network. Since the current optical backbone is actually divided to multiple domains according to the different network providers, it is necessary to study the waveband grooming in multi-domain optical networks. However, waveband grooming in multi-domain optical networks is more challenging than that in single domain networks because of the routing scalability and security issues. Therefore, in this paper, we propose a new heuristic Hierarchical Multi-domain Waveband Grooming (HMWG) algorithm based on Hierarchical Integrated Grooming Auxiliary Graph (H-IGAG) to reduce the total number of optical switching ports. The H-IGAG is compared of the Intra-domain Waveband Integrated Auxiliary Graph (Intra-WIAG) and the Inter-domain waveband Virtual Topology Graph (Inter-VTG). For the demand in single-domain, HMWG directly computes the route from the source node to destination node in the single-domain with waveband grooming on Intra-WIAG. For the demand spanning different domains, HMWG first computes the route from the source node to the selected border node in source domain and computes the route from the selected border node to the destination node in destination domain with waveband grooming on Intra-WIAG, respectively. Then, HMWG computes the route from the selected border node in source domain to the selected border node in destination domain with waveband grooming on Inter-VTG. Simulation results show that, compared with previous grooming algorithm, HMWG can obtain better performance.

Multicast Grooming Algorithm in Waveband Switching Optical Networks

In optical Wavelength-Division-Multiplexing (WDM) networks, multicast becomes more and more popular to provide high-speed communication between one point and multiple points. At the same time, the ports of Optical Cross-Connect (OXC) are greatly enhanced with the increasing number of wavelengths in fibers, and then the waveband switching technique is proposed to save the ports and reduce the cost of OXC. However, current waveband grooming algorithms are all limited in unicast. To achieve the multicast communication and meanwhile save the ports of OXC, we need to solve the multicast grooming, routing and wavelength/waveband assignment problem which is the HP-hard. In this paper, we propose a heuristic algorithm named Integrated Multicast Waveband Grooming (IMWG) based on Multicast Layered Auxiliary Graph (MLAG) that includes a Virtual Topology Layer (VTL) and multiple Waveband-Plane Layers (WPLs) to support the single-hop, multi-hop and hybrid multicast waveband grooming. For each demand, IMWG first computes a single-hop or multi-hop grooming waveband-tree on VTL. If the grooming waveband-tree cannot be found on VTL, IMWG computes a new waveband-tree on WPL. If the new waveband-tree cannot be found on WPL, IMWG computes a hybrid grooming waveband-tree on MLAG. Simulation results show that, compared with other algorithms, IMWG is able to obtain better performances.

Protection schemes with waveband grooming in fault-tolerant multidomain optical networks

In wavelength-division-multiplexing networks, the fault-tolerance is very important since failures may lead to a significant amount of data loss. At the same time, the waveband switching technique is very interesting since it can save switching ports in optical cross-connections. In addition, the hierarchical routing in multidomain optical networks is very challenging since the interdomain routing is based on aggregative virtual topology. However, previous works did not jointly consider the three issues. We propose two schemes, segment-based protection (SBP) and path-based protection (PBP), to provide the fault-tolerance and waveband grooming in multidomain optical networks. In SBP, for each connection we first compute an interdomain loose route based on virtual topology, and then we compute the intradomain exact path-pairs in each single domain traversed by the loose route based on physical topology. In PBP, for each connection we first compute an interdomain loose primary path and an interdomain loose backup path based on virtual topology, and then we compute the intradomain exact paths in each single domain traversed by the loose primary path and backup path based on the physical topology. To support multidomain waveband grooming, we present the layered auxiliary graph. Simulation results show that PBP performs better than SBP.

Waveband Grooming based on Layered Auxiliary Graph in multi-domain optical networks

With the number of wavelengths on fibers keeps increasing, the size and the cost of Optical Cross-Connect (OXC) are greatly enhanced and then the control and management of optical switches become more and more complicated. Therefore, the technique called waveband switching is proposed to reduce the size and the cost of OXC; that is, to save the All-Optical (OOO) switching ports in OXC. However, the existing waveband switching algorithms are all limited in single-domain optical networks. Actually, with the scale of optical backbone keeps enlarging, the network is divided to multiple independent domains to perform the hierarchy routing for achieving the scalability. In order to reduce the size and the cost of OXC meanwhile to achieve the scalability in multi-domains, in this paper we propose a new heuristic algorithm called Waveband Grooming with Layered Auxiliary Graph (WGLAG) since the waveband grooming problem is the NP-hard to perform the inter-domain routing based on the virtual topology of multi-domain network and the intra-domain routing based on the physical topology of single-domain network. In intra-domain routing with waveband grooming of each single-domain, we propose the Layered Auxiliary Graph (LAG) that includes one virtual topology layer and multiple waveband-plane layers to compute a single-hop, or multi-hop or hybrid waveband route for each connection request based on the sub-path waveband grooming scheme. Simulation results show that, WGLAG not only can effectively save more switching ports to reduce the cost of OXC but also can obtain lower blocking probability than other algorithm.

Routing and wavelength assignment in hierarchical WDM networks

A new routing and wavelength assignment method applied in hierarchical wavelength division multiplexing (WDM) networks is proposed. The algorithm is called offline band priority algorithm (offline BPA). The offline BPA targets to maximize the number of waveband paths under the condition of minimum number of wavelengths, and solve the routing and wavelength assignment (RWA) problem with waveband grooming to reduce cost. Based on the circle construction algorithm, waveband priority function is introduced to calculate the RWA problem. Simulation results demonstrate that the proposed algorithm achieves significant cost reduction in WDM network construction.

Traffic grooming in hybrid ring-star optical networks

The increasing demand for Internet network capacity requires optical traffic-grooming technology to reduce the complexity of the network. A network with optical cross connects is one potential architecture to achieve this goal. We show that an alternate architecture based on a hybrid ring-star topology and waveband grooming helps to reduce the network complexity by minimizing the number of nodes and the number of ports required in each node. We develop an analytical method for the design of hybrid ring-star topologies to reduce the capital cost of the overall optical network. We evaluate the performance of our method in terms of the number of network elements required for a national backbone network and demonstrate its savings in comparison to waveband grooming.

Call for Papers: Waveband Switching, Routing, and Grooming

Call for Papers: Waveband Switching, Routing, and Grooming Coordinating Associate Editor Jun Zheng, University of Ottawa Guest Editor Jason P. Jue, The University of Texas at Dallas Submission deadline: 1 May 2006 The rapid advances in dense wavelength-division multiplexing (DWDM) technology have enabled the provisioning of hundreds of wavelengths on a single fiber, which has brought about a large increase in the size of optical cross-connects (OXCs) as well as in the cost and control complexity of such OXCs. Waveband switching (WBS) is a concept recently introduced to reduce the cost and control complexity of OXCs. The basic idea of WBS is to group a set of wavelengths together into a waveband and transmit and switch the waveband optically using a single port. In a WBS network, a waveband is transmitted and switched as a single entity whenever possible and is demultiplexed into individual wavelengths only if necessary. A multigranular OXC (MG-OXC) is employed not only to switch traffic at multiple levels or granularities such as fiber, waveband, and wavelength, but also to add and drop traffic at multiple granularities. Traffic can also be transported from one level to another via multiplexers within the MG-OXC. By using WBS, the number of ports of an OXC can be significantly reduced, leading to reduced size, cost, and control complexity of the OXC. Because of its practical importance, WBS has attracted much attention from both industry and academia in recent years. To realize the vision of a WBS network, it is critical to solve various related problems, such as switch architecture and algorithm design. Owing to the differences in network design objectives, however, traditional techniques developed for wavelength-routed networks (WRNs) cannot be directly applied to WBS networks. This has motivated a large amount of research activities in recent years that seeks effective solutions to WBS related problems. The aim of this feature issue is to present a collection of high-quality research papers that reflect the state-of-the-art research progresses and results in this focus area. Scope of Submission The aim of this feature issue is to present a collection of high-quality research papers that focus on wavelength switching, routing, and grooming. We are soliciting original contributions that were previously unpublished and are currently not under consideration by any other journal. As applicable to this theme, topics of interests include but are not limited to: Waveband switching Waveband routing Waveband assignment Waveband grooming Waveband conversion Switch/OXC architecture Multi-granular switch/OXC Waveband and wavelength multiplexing Hierarchical cross-connect WDM networks Waveband control and management Waveband protection and restoration Performance modeling and analysis Experimental field trials Manuscript Submission To submit to this special issue, follow the normal procedure for submission to JON, indicating ``WBS' in the ``Comments' field of the online submission form. For all other questions relating to this feature issue, please send an e-mail to jon@osa.org, subject line ``WBS.' Additional information can be found on the JON website: http://www.osa-jon.org/submission/. Submission Deadline: 1 May 2006

Call for Papers: Waveband Switching, Routing, and Grooming

Call for Papers: Waveband Switching, Routing, and Grooming

Call for Papers: Waveband Switching, Routing, and Grooming

Call for Papers: Waveband Switching, Routing, and Grooming Coordinating Associate Editor Jun Zheng, University of Ottawa Guest Editor Jason P. Jue, The University of Texas at Dallas Submission deadline: 1 May 2006 The rapid advances in dense wavelength-division multiplexing (DWDM) technology have enabled the provisioning of hundreds of wavelengths on a single fiber, which has brought about a large increase in the size of optical cross-connects (OXCs) as well as in the cost and control complexity of such OXCs. Waveband switching (WBS) is a concept recently introduced to reduce the cost and control complexity of OXCs. The basic idea of WBS is to group a set of wavelengths together into a waveband and transmit and switch the waveband optically using a single port. In a WBS network, a waveband is transmitted and switched as a single entity whenever possible and is demultiplexed into individual wavelengths only if necessary. A multigranular OXC (MG-OXC) is employed not only to switch traffic at multiple levels or granularities such as fiber, waveband, and wavelength, but also to add and drop traffic at multiple granularities. Traffic can also be transported from one level to another via multiplexers within the MG-OXC. By using WBS, the number of ports of an OXC can be significantly reduced, leading to reduced size, cost, and control complexity of the OXC. Because of its practical importance, WBS has attracted much attention from both industry and academia in recent years. To realize the vision of a WBS network, it is critical to solve various related problems, such as switch architecture and algorithm design. Owing to the differences in network design objectives, however, traditional techniques developed for wavelength-routed networks (WRNs) cannot be directly applied to WBS networks. This has motivated a large amount of research activities in recent years that seeks effective solutions to WBS related problems. The aim of this feature issue is to present a collection of high-quality research papers that reflect the state-of-the-art research progresses and results in this focus area. Scope of Submission The aim of this feature issue is to present a collection of high-quality research papers that focus on wavelength switching, routing, and grooming. We are soliciting original contributions that were previously unpublished and are currently not under consideration by any other journal. As applicable to this theme, topics of interests include but are not limited to: Waveband switching Waveband routing Waveband assignment Waveband grooming Waveband conversion Switch/OXC architecture Multi-granular switch/OXC Waveband and wavelength multiplexing Hierarchical cross-connect WDM networks Waveband control and management Waveband protection and restoration Performance modeling and analysis Experimental field trials Manuscript Submission To submit to this special issue, follow the normal procedure for submission to JON, indicating ``WBS' in the ``Comments' field of the online submission form. For all other questions relating to this feature issue, please send an e-mail to jon@osa.org, subject line ``WBS.' Additional information can be found on the JON website: http://www.osa-jon.org/submission/. Submission Deadline: 1 May 2006

Call for Papers: Waveband Switching, Routing, and Grooming

Call for Papers: Waveband Switching, Routing, and Grooming Coordinating Associate Editor Jun Zheng, University of Ottawa Guest Editor Jason P. Jue, The University of Texas at Dallas Submission deadline: 1 May 2006 The rapid advances in dense wavelength-division multiplexing (DWDM) technology have enabled the provisioning of hundreds of wavelengths on a single fiber, which has brought about a large increase in the size of optical cross-connects (OXCs) as well as in the cost and control complexity of such OXCs. Waveband switching (WBS) is a concept recently introduced to reduce the cost and control complexity of OXCs. The basic idea of WBS is to group a set of wavelengths together into a waveband and transmit and switch the waveband optically using a single port. In a WBS network, a waveband is transmitted and switched as a single entity whenever possible and is demultiplexed into individual wavelengths only if necessary. A multigranular OXC (MG-OXC) is employed not only to switch traffic at multiple levels or granularities such as fiber, waveband, and wavelength, but also to add and drop traffic at multiple granularities. Traffic can also be transported from one level to another via multiplexers within the MG-OXC. By using WBS, the number of ports of an OXC can be significantly reduced, leading to reduced size, cost, and control complexity of the OXC. Because of its practical importance, WBS has attracted much attention from both industry and academia in recent years. To realize the vision of a WBS network, it is critical to solve various related problems, such as switch architecture and algorithm design. Owing to the differences in network design objectives, however, traditional techniques developed for wavelength-routed networks (WRNs) cannot be directly applied to WBS networks. This has motivated a large amount of research activities in recent years that seeks effective solutions to WBS related problems. The aim of this feature issue is to present a collection of high-quality research papers that reflect the state-of-the-art research progresses and results in this focus area. Scope of Submission The aim of this feature issue is to present a collection of high-quality research papers that focus on wavelength switching, routing, and grooming. We are soliciting original contributions that were previously unpublished and are currently not under consideration by any other journal. As applicable to this theme, topics of interests include but are not limited to: Waveband switching Waveband routing Waveband assignment Waveband grooming Waveband conversion Switch/OXC architecture Multi-granular switch/OXC Waveband and wavelength multiplexing Hierarchical cross-connect WDM networks Waveband control and management Waveband protection and restoration Performance modeling and analysis Experimental field trials Manuscript Submission To submit to this special issue, follow the normal procedure for submission to JON, indicating ``WBS' in the ``Comments' field of the online submission form. For all other questions relating to this feature issue, please send an e-mail to jon@osa.org, subject line ``WBS.' Additional information can be found on the JON website: http://www.osa-jon.org/submission/. Submission Deadline: 1 May 2006

Waveband grooming and IP aggregation in optical networks

An automatically switched optical network (ASON) can be used as the transport layer of generalized multiprotocol label switching (GMPLS) networks. The design of an ASON involves determining the number of optical cross-connects (OXC) in the network, the required number of ports per OXC, and the interconnection topology of the OXCs. Given the number of ports per OXC, we present a linear algorithm to find the number of OXCs and to identify a cost-effective topology. We then develop a scheme that can be used to perform waveband grooming for several different topologies of an ASON that uses single-layer multigranular OXCs. We identify the bottlenecks and investigate the effect of traffic grooming schemes in the design of an ASON as a function of the peak access rate per customer. We evaluate the topologies and architectures for a national trunk network.