Optical Transport Network

About: Optical Transport Network is a research topic. Over the lifetime, 6055 publications have been published within this topic receiving 85783 citations.

Cost and Reliability Considerations in Designing the Next-Generation IP over WDM Backbone Networks

Abstract: To accommodate the increasing demands for bandwidth, Internet Service Providers (ISPs) have deployed higher-speed links and reconfigurable optical add drop multiplexers (ROADMs) in their backbone networks. To address the reliability challenges due to failures and planned outages, ISPs typically use two backbone routers at each central office in a dual-home configuration. Thus at the IP layer, redundant backbone routers as well as redundant transport equipment to interconnect them are deployed to provide reliability through node and path diversity. However, adding such redundant resources increases the overall cost of the network. Hence, a fundamental redesign of the backbone network which avoids such redundant resources by leveraging the capabilities of an intelligent optical transport network is a highly desirable objective. It is clear that such a redesign must lower costs without compromising on the reliability achieved by today's backbone networks. Modeling the costs and reliability of the network at all layers is an important step in achieving this objective. In this paper, we undertake an in-depth investigation of the cost and reliability considerations involved in designing the next-generation backbone network. Our work includes a detailed analysis of the operation, cost and reliability of the network at the IP layer and the multiple layers below it. We discuss alternative backbone network designs which use only a single router at each central office but use the optical transport layer to carry traffic to routers at other offices in order to survive failures or outages of the single local router. We discuss trade-offs involved in using these designs.

Elementary photonic switching modules in three divisions

Abstract: In three-divisional photonic switching networks, data is interchanged among channels that are formed in space, time, and wavelength This paper presents several techniques for designing the architectures of small photonic switching modules that switch in three divisions In one technique, Marcus' (1970) classical transformation from a space-only Clos network to a time-space-time architecture is generalized to the wavelength division and extended to three divisions In another technique, Hunter's (see IEEE J Lightwave Technol, vol11, no3, p495-511, 1993) space-time transformation is also generalized and extended to three divisions It is illustrated on several classical network architectures, including the most elementary case of a three-division photonic switching module based on the Benes (1965) architecture: an eight-by-eight network in which each side has two fibers and each fiber has two wavelengths and two timeslots

Optical wavelength selection control system in optical networks

Abstract: An optical wavelength selection control system in an optical network includes an optical center node device and a plurality of terminal devices each comprised of a work station and an interface. The optical center node device includes a control circuit, a plurality of optical switches and a plurality of tunable wavelength filters. When there occurs a collision among the plurality of terminal devices wherein a plurality of terminal devices send simultaneously optical packets to the same terminal device, the control circuit operates to control the optical switches and the tunable wavelength filters such that they select only one optical packet, based on information relating to, for example, a data length to be transferred. The control circuit sends out an acknowledgment (ACK) signal to the terminal device whose optical packet has been selected. To each of the terminal devices whose optical packets have not been selected, the control circuit sends out, in addition to a not-acknowledgement (NACK) signal, a signal indicating a resending time schedule. There are no possibilities any more for at least these optical packets to be involved in the collision problems, and this ensures an enhancement of the throughput of the network system.

A novel optical networking scheme utilizing coarse granular optical routing and fine granular add/drop

Abstract: We propose a novel network architecture that exploits coarse granular routing while add/drop operations are done at wavelength granularity. Node architecture and the network design algorithm are introduced. Numerical results verify its cost efficacy.

Method and device for setting up and operating a modular, highly scalable, very simple, cost-efficient and enduring transparent optically routed network for network capacities of greater than 1 Petabit/s

Abstract: A method for setting up, operating and/or scaling a modular optically routed transport network includes: providing a quasi passive Optical Transport Network (OTN) core network according to ITU-T G709 with N network nodes at the core network edge; providing at least one active component in each network node for the transmission of data over the core network; and changing at least one of the at least one active component in at least one network node for scaling the network The at least one active component is an optical transceiver comprising digital signal processors (DSPs)