The Case for Opaque Multiwavelength Optical Networks

Arisoylu

2003

SPIE Proceedings

We discuss the problem of designing translucent optical networks composed of restorable, transparent subnetworks interconnected via transponders. We formulate the problem of designing restorable subnetworks in translucent networks as an Integer Linear Programming (ILP) problem, where the subnetworks are determined subject to the constraints that each subnetwork satisfies size limitations and it is 2-connected. A greedy heuristic algorithm for the same problem is also proposed for planar network topologies.We propose section restoration for translucent networks where failed connections are rerouted inside the subnetwork which contains the failed link. The network design problem of determining working and restoration capacities with section restoration is formulated as an ILP problem. Numerical results show that section restoration generates fiber costs which are close to those with the path restoration technique for the mesh topologies used in this study. It is also shown that the number of transponders with the translucent optical network is substantially reduced compared to opaque networks.

Section: Partitioning With Ilp Formulationmentioning

confidence: 99%

“…46 Second type of optical networks is the opaque network architecture. 7 In opaque networks, a connection passes through optical/electronic/optical converters, called transponders, at each node. Opaque networks may utilize optical or electronic form of switching at intermediate nodes.…”

Section: Introductionmentioning

confidence: 99%

Subnetwork partitioning and section restoration in translucent optical networks

Arisoylu

2003

SPIE Proceedings

“…A second type of optical networks is the opaque network architecture [7]. In opaque networks, a connection passes through optical/electronic/optical converters, called transponders, at each node.…”

Section: Introductionmentioning

confidence: 99%

Design of Translucent Optical Networks: Partitioning and Restoration

Photonic Network Communications

Arisoylu

2004

Abstract. We discuss the problem of designing translucent optical networks composed of restorable, transparent subnetworks interconnected via transponders. We develop an integer linear programming (ILP) formulation for partitioning an optical network topology into subnetworks, where the subnetworks are determined subject to the constraints that each subnetwork satis®es size limitations, and it is two-connected. A greedy heuristic partitioning algorithm is proposed for planar network topologies.We use section restoration for translucent networks where failed connections are rerouted within the subnetwork which contains the failed link. The network design problem of determining working and restoration capacities with section restoration is formulated as an ILP problem. Numerical results show that ®ber costs with section restoration are close to those with path restoration for mesh topologies used in this study. It is also shown that the number of transponders with the translucent network architecture is substantially reduced compared to opaque networks.

“…In the optical networks currently being deployed, each link is optically isolated by transponders that are employing O/E/O conversions, and these networks are called opaque [15]. Since transponders increase the network cost and they are bit-rate and format speci®c, there is a tendency to introduce all-optical subnetworks called domains of transparency [16].…”

Section: Introductionmentioning

confidence: 99%

Untitled

Yetginer

Photonic Network Communications

2003

Abstract. In this paper, we study regenerator placement and traf®c engineering of restorable paths in generalized multiprotocol label switching (GMPLS) networks. Regenerators are necessary in optical networks in order to cope with transmission impairments. We study a network architecture where regenerators are placed only at selected nodes for decreasing cost of regeneration. We propose two heuristic algorithms for optimum placement of these regenerators. Performances of these algorithms in terms of required number of regenerators and computational complexity are evaluated. In this network architecture with sparse regeneration, off-line computation of working and restoration paths is studied for traf®c engineering with path rerouting as the restoration scheme. We study two approaches for selecting working and restoration paths from a set of candidate paths and formulate each method as an integer linear programming (ILP) problem. A traf®c uncertainty model is developed in order to compare these methods based on their robustness with respect to changing traf®c patterns. Traf®c engineering methods are compared based on number of additional demands resulting from traf®c uncertainties that can be carried over the network. Proposed heuristic regenerator placement algorithms are also evaluated from a traf®c engineering point of view.