Fiber Optic Wiki

History of transport networks

July 18, 2011

Transport networks, the underlying optical fiber-based layer of telecommunications networks, have evolved from Digital cross connect system (DCS)-based mesh architectures in the 1980s, to SONET/SDH (Synchronous Optical Networking/Synchronous Digital Hierarchy) ring architectures in the 1990s. In DCS-based mesh architectures, telecommunications carriers deployed restoration systems for DS3 circuits such as at&t FASTAR (FAST Automatic Restoration)[1] and MCI Real Time Restoration (RTR), restoring circuits in minutes after a network failure. In SONET/SDH rings, carriers implemented ring protection such as SONET Universal Path Switched Ring (UPSR) (also called Sub-Network Connection Protection (SCNP) in SDH networks) or SONET Bidirectional Line Switched Ring (BLSR)[4] (also called Multiplex Section - Shared Protection Ring (MS-SPRing) in SDH networks), protecting against and recovering from a network failure in 50 msecs or less[5], a significant improvement over the recovery time supported in DCS-based mesh restoration, and a key driver for the deployment of SONET/SDH ring-based protection.

Optical mesh networks 2

July 18, 2011

Optical mesh networks refer to transport networks that are built directly off the mesh-like fiber infrastructure deployed in metropolitan, regional, national, or international (e.g., trans-oceanic) areas by deploying optical transport equipment that are capable of switching traffic (at the wavelength or sub-wavelength level) from an incoming fiber to an outgoing fiber. In addition to switching wavelengths, the equipment is typically also able to multiplex lower speed traffic into wavelengths for transport, and to groom traffic (as long as the equipment is so-called opaque - see subsection on transparency). Finally, these equipment also provide for the recovery of traffic in case of a network failure. As most of the transport networks evolve toward mesh topologies utilizing intelligent network elements (optical cross-connects or optical switches [8]) for provisioning and recovery of services, new approaches have been developed for the design, deployment, operations and management of mesh optical networks.

Recovery in optical mesh networks

July 18, 2011

Optical mesh networks support the establishment of circuit-mode connection-oriented services. Multiple recovery mechanisms that provide different levels of protection or restoration against different failure modes are available in mesh networks. Channel, link, segment and path protection are the most common protection schemes. P-cycles is another type of protection that leverages and extends ring-based protection. Restoration is another recovery method that can work on its own or complement faster protection schemes in case of multiple failures.

Fiber Optic Video Transmission is Booming While Waiting for an Even Bigger Boom

July 16, 2011

Hospital operating rooms in cinemas, Traffic Control Center to become high quality video is ubiquitous, and in a growing number of demanding applications, optical fiber cables, such as the distribution vehicle choice.

Optical fiber connector

July 16, 2011

An optical fiber connector terminates the end of an optical fiber, and enables quicker connection and disconnection than splicing. The connectors mechanically couple and align the cores of fibers so that light can pass. Most optical fiber connectors are spring-loaded: The fiber endfaces of the two connectors are pressed together, resulting in a direct glass to glass or plastic to plastic contact, avoiding any glass to air or plastic to air interfaces, which would result in higher connector losses.

Optical fiber connector Analysis

July 16, 2011

FC connectors' floating ferrule provides good mechanical isolation. FC connectors need to be mated more carefully than the push-pull types due to the need to align the key, and due to the risk of scratching the fiber endface while inserting the ferrule into the jack. FC connectors have been replaced in many applications by SC and LC connectors.

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