Richard E. Wagner

Polarization dispersion and principal states in a 147-km undersea lightwave cable

The authors describe measurements of polarization dispersion in a 147-km undersea lightwave cable at 1.56 mu m. The wavelength dependence of the transmitted state of polarization was measured and interpreted in terms of the principal states description of polarization dispersion to determine the difference in the propagation delay time between the two principal states of polarization. Measured differential propagation delay times ranged between 2.5 and 10 ps among the four fibers tested. Significant wavelength dependence in both the principal states and the propagation delay times was observed over a 12-AA interval. >

Fiber-Based Broadband-Access Deployment in the United States

After more than 20 years of research and development, a combination of technological, regulatory, and competitive forces are finally bringing fiber-based broadband access to commercial fruition. The three main approaches-hybrid fiber coax, fiber to the cabinet, and fiber to the home-are each vying for dominance in the industry, and each has significant future potential to grow customers and increase bandwidth and associated-service offerings. Further technical advances and cost reductions will be adopted, eventually bringing performance levels and bandwidth to gigabits-per-second rates when user demand warrants while keeping service costs affordable

Transparent optical protection ring architectures and applications

This paper reviews recent progress in optical protection rings with the focus on transparent optical protection rings. Different optical protection ring architectures, such as dedicated and shared protection rings, in both the optical-channel (OCh) layer and the optical multiplex section (OMS) layer, are described. In particular, OCh shared protection rings (OChSPRINGs) are discussed in detail including node-architecture designs, ring protocols, triggers, and messaging channels. Feasibility studies and experimental results from Corning Inc. and other companies are reviewed. The paper also discusses how protection-switching times scale with number of nodes and number of wavelengths, and shows examples of applications using the scaling rules for practical optical networks such as metro, regional, and long-haul ring networks. The cost benefits of transparent optical protection rings are analyzed using a typical metro network. Finally, the paper discusses remaining issues and future developments in the optical protection ring area.

The potential of optical layer networks

There is enormous potential in newly emerging optical layer networks that support a rapidly growing Internet backbone. This potential stems from the value of extended reach to remove costly regenerators, the value of configurability to reduce provisioning times between IP routers, and the value of optical peering to increase the efficiency of the EP backbone network.

Metro network architecture scenarios, equipment requirements and implications for carriers

Metropolitan network traffic demands are used to project network topology and element characteristics assuming several different market penetrations for existing (ILEC) and new (CLEC) carriers.

Traffic Studies for Fast Optical Switching in an Intelligent Optical Network

The optical layer of the transport network is expected in the (near) future to make the transition from a statically configured layer to a fully flexible, automatic and intelligent layer. Such an intelligent optical network (ION) allows to set up (or tear down) bandwidth between two nodes on demand, following a simple request of the client network layer: the so-called switched connections. For successful deployment of these switched connections it is of utmost importance to have a well-educated idea about the granularities of the traffic flows in the optical transport network. Deploying switched connections with a capacity of 10 Gbps to transport a traffic demand with a granularity of a few hundred Mbps does not exactly make efficient use of the network resources. In this paper, the granularity of the traffic demand between US metro areas is investigated for two future points in time, namely 2006 and 2010. For this study we focus on the traffic flows between two metro area entities: the points of presence (PoPs) or the main aggregation points of the customer traffic in a metro area, and the collector central offices (COs) or the nodes a bit further in the metro area, closer to the end-customers. We have found that a significant portion of the total traffic volume at these moments in time will qualify for transport using switched connections with a capacity of 10 Gbps. According to our study, in 2006 around one third of the traffic will qualify for transportation in such 10 Gbps connections between PoPs in different metro areas, while by 2010 this amount will have increased to more than 99%. The traffic granularity between the collector COs, however, will in 2006 still be too small to justify the use of direct 10 Gbps connections, but in 2010 almost three quarter of the traffic could make use of 10 Gbps direct connections from collector CO to collector CO. These results enable us to sketch the expected network evolution scenario and determine the type and size of equipment needed in the different steps of the network evolution. The optical edge aggregation switches will have to be moved deeper into the metro area with time: in 2006 they will be needed at the PoPs, while by 2010 they could be placed at the collector COs.

Design, transport performance study and engineering of a 11 Tb/s US mesh metro network

A new top-down simulation methodology for successfully enabling transparent optical networks in the metro environment is presented. A 11 Tb/s ILEC network was engineered based on projected traffic demands for a typical medium size US metropolitan area. The approach combines traffic modeling, network dimensioning, and transport layer performance modeling. The latter is further composed of three main simulation steps: efficient wavelength-domain simulations for network crosstalk analysis, time-domain simulation for determining Q-penalties for pulse propagation effects and finally a Q-budgeting approach that combines the above results for flexible network design and engineering. As a result metro players like ILECs or CLECs can effectively and quickly engineer transparent networks in the metro environment using simulation methodologies like the above. Details on the actual traffic and transport layer models used as well as experimental validation results for the models will be presented in more detail at the conference.

Techno-economic study of the value of high stimulated Brillouin scattering threshold single-mode fiber utilization in fiber-to-the-home access networks

Cost modeling reveals that deployment of fibers with a high stimulated Brillouin scattering threshold in fiber-to-the-home access networks can reduce material and labor expenditures by more than 20%. Theory and measurements of the high stimulated Brillouin scattering fiber are presented to demonstrate its employability.

Interconnection of metropolitan and backbone networks

As Internet traffic continues to grow, eventually dominating voice traffic, the network economics and traffic granularities may become favorable for merging the metropolitan core with the long-distance backbone network, to form an integrated 10 Gb/s wavelength-routed network architecture.

A bottom-up traffic demand model for long haul and metropolitan optical networks

A bottom-up traffic model featuring traffic demand estimations, application-specific growth projections and detailed demand-to-working network capacity conversion factors is described and applied to both long haul and metropolitan networks (with >85% accuracy).