Yukio Tsukishima

Spectrum-efficient and scalable elastic optical path network: architecture, benefits, and enabling technologies

The sustained growth of data traffic volume calls for an introduction of an efficient and scalable transport platform for links of 100 Gb/s and beyond in the future optical network. In this article, after briefly reviewing the existing major technology options, we propose a novel, spectrum- efficient, and scalable optical transport network architecture called SLICE. The SLICE architecture enables sub-wavelength, superwavelength, and multiple-rate data traffic accommodation in a highly spectrum-efficient manner, thereby providing a fractional bandwidth service. Dynamic bandwidth variation of elastic optical paths provides network operators with new business opportunities offering cost-effective and highly available connectivity services through time-dependent bandwidth sharing, energy-efficient network operation, and highly survivable restoration with bandwidth squeezing. We also discuss an optical orthogonal frequency-division multiplexing-based flexible-rate transponder and a bandwidth-variable wavelength cross-connect as the enabling technologies of SLICE concept. Finally, we present the performance evaluation and technical challenges that arise in this new network architecture.

Demonstration of novel spectrum-efficient elastic optical path network with per-channel variable capacity of 40 Gb/s to over 400 Gb/s

We demonstrated, for the first time, a novel spectrum-efficient elastic optical path network for 100 Gb/s services and beyond, based on flexible rate transceivers and variable-bandwidth wavelength crossconnects.

Bandwidth Squeezed Restoration in Spectrum-Sliced Elastic Optical Path Networks (SLICE)

With the continuing growth in the amount of backbone traffic, improving the cost-effectiveness and ensuring survivability of the underlying optical networks are very important problems facing network service providers today. In this paper, we propose a bandwidth squeezed restoration (BSR) scheme in our recently proposed spectrum-sliced elastic optical path network (SLICE). The proposed BSR takes advantage of elastic bandwidth variation in the optical paths of SLICE. It enables spectrally efficient and highly survivable network recovery for best-effort traffic as well as bandwidth guaranteed traffic, while satisfying the service level specifications required from the client layer networks. We discuss the necessary interworking architectures between the optical path layer and client layer in the BSR in SLICE. We also present a control framework that achieves flexible bandwidth assignment as well as BSR of optical paths in SLICE. Finally, we describe an implementation example of a control plane using generalized multi-protocol label switching (GMPLS).

Optical Path Aggregation for 1-Tb/s Transmission in Spectrum-Sliced Elastic Optical Path Network

We propose and experimentally demonstrate optical path aggregation in a spectrum-sliced elastic optical path network (SLICE). Multiple optical orthogonal frequency-division-multiplexed (OFDM) 100-Gb/s optical paths are aggregated in the optical domain to form a spectrally continuous 1-Tb/s super-wavelength optical path and transmitted over a network of bandwidth-variable wavelength cross-connects. We evaluate the potential implementation issues and conclude that the OFDM paths can be optically aggregated with optical signal-to-noise ratio penalty of less than 1 dB.

Virtualized optical network (VON) for agile cloud computing environment

A virtualized optical network is proposed as a key to implementing increased agility and flexibility into a cloud computing environment by providing any-to-any connectivity with the appropriate optical bandwidth at the appropriate time.

The first functional demonstration of optical virtual concatenation as a technique for achieving terabit networking

The optical virtual concatenation (OVC) function of The Terabit LAN was demonstrated for the first time at the iGrid 2005 workshop in San Diego, California. The TERAbit-LAN establishes a lambda group path (LGP) for an application where the number of lambdas/L2 connections in a LGP can be specified by the application. Each LGP is logically treated as one end-to-end optical path, so during parallel transport, the LGP channels have no relative latency deviation. However, optical path diversity (e.g. restoration) can cause LGP relative latency deviations and negatively affect quality of service. OVC hardware developed by NTT compensates for relative latency deviations to achieve a virtual bulk transport for the Electronic Visualization Laboratorys (EVL) Scalable Adaptive Graphics Environment application.

Demonstration of colorless and directed/directionless ROADMs in router network

We demonstrate dynamic optical path operation of colorless ROADM and connection switching between routers in a router network. We also evaluate and demonstrate both colorless-directed ROADM and colorless-directionless ROADM in a router network.

Joint storage-network resource management for super high-definition video delivery service

This paper proposes a joint storage-network resource management for a super high-definition video delivery service. The method for allocating storage and optical path resources is discussed. The feasibility of the proposed system is shown.

The First Application-driven Lambda-on-Demand Field Trial over a US Nationwide Network

The Lambda-on-demand functionality with link aggregation to accommodate the dynamic bandwidth demands of an ultra-high-resolution visualization application was realized in over a US nationwide photonic network for the first time.

Power-efficient multi-layer networking: design and evaluation

With the exponential growth in the amount of Internet traffic, power consumption in the networking field has become a paramount issue. This paper focuses on the design of power-efficient multi-layer networks that comprise both the optical layer and the Internet Protocol (IP) layer, and analyzes several approaches such as power-efficient routing of lightpaths and power-efficient configuration of network devices. Based on practical network equipment and network architecture, this paper proposes a set of complete mathematical formulations to model comparatively complicated multi-layer networks, and utilizes Integer Linear Programming (ILP) to investigate the power-conservation effect through optimization. Simulation results indicate that significant power can be conserved with the power-efficient network design.