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.

SONET: now it's the standard optical network

Abstract: The authors discuss aspects of the SONET (synchronous optical network) standards and standardization process, both national and international, that they consider to be of particular interest. Restricting their attention to the standard dealing with rates and formats, they consider the SONET signal hierarchy, overhead channels, multiplexing, STS-1 payload pointer, sub-STS-1 payloads, and optical interface parameters. They include a brief history of the SONET standard and an outline of future work. >

MEMS: the path to large optical crossconnects

Abstract: Continuous growth in demand for optical network capacity and the sudden maturation of WDM technologies have fueled the development of long-haul optical network systems that transport tens to hundreds of wavelengths per fiber, with each wavelength modulated at 10 Gb/s or more. Micro-electromechanical systems devices are recognized to be the enabling technologies to build the next-generation cost-effective and reliable high-capacity optical crossconnects. While the promises of automatically reconfigurable networks and bit-rate-independent photonic switching are bright, the endeavor to develop a high-port-count MEMS-based OXC involves overcoming challenges in MEMS design and fabrication, optical packaging, and mirror control. Due to the interdependence of many design parameters, manufacturing tolerances, and performance requirements, careful trade-offs must be made in MEMS device design as well as system design. We provide an overview of the market demand, various design trade-offs, and multidisciplinary system considerations for building reliable and manufacturable large MEMS-based OXCs.

On double-link failure recovery in WDM optical networks

Abstract: Network survivability is a crucial requirement in high-speed optical networks. Typical approaches of providing survivability have considered the failure of a single component such as a link or a node. We consider a failure model in which any two links in the network may fail in an arbitrary order. Three loopback methods of recovering from double-link failures are presented. The first two methods require the identification of the failed links, while the third one does not. However, precomputing the backup paths for the third method is more difficult than for the first two. A heuristic algorithm that pre-computes backup paths for links is presented. Numerical results comparing the performance of our algorithm with other approaches suggests that it is possible to achieve 100% recovery from double-link failures with a modest increase in backup capacity.

Failure location algorithm for transparent optical networks

Abstract: Fault and attack management has become a very important issue for network operators that are interested to offer a secure and resilient network capable to prevent and localize, as accurately as possible, any failure (fault or attack) that may occur. Hence, an efficient failure location method is needed. To locate failures in opaque optical networks, existing methods which allow monitoring of the optical signal at every regeneration site can be used. However, to the best of our knowledge, no method exists today that performs failure location for transparent optical networks. Such networks are more vulnerable to failures than opaque networks since failures propagate without being isolated due to optoelectronic conversions. In this paper, we present a failure location algorithm that aims to locate single and multiple failures in transparent optical networks. The failure location algorithm developed in this paper can cope with ideal scenarios (i.e., no false and/or lost alarms), as well as with nonideal scenarios having false and/or lost alarms.

Architectural considerations involved in the design of an optical digital computer

Abstract: Communication problems such as interconnection bandwidth, clock skew, and connectivity restrict computational throughput. Bandwidth and clock skew problems limit the speed and add to the design complexity. Constrained connectivity forces a significant portion of the speed of a processor to be used to compensate for the limited number of interconnections. Philosophically, the large bandwidth, innate parallelism, and noninterfering propagation of optics offer mechanisms for overcoming these communication problems. The difficulty in exploiting these capabilities has been the absence of suitable optical logic and memory devices. Technologically, optical bistability and other advances in electrooptics now offer the possibility of cascadable optical logic elements with speed and power dissipation comparable with electronics. Architecturally, a parallel pipelined structure can be used to simplify the optical memory requirements as well as exploit the communication capabilities of optics.