Fiberdyne Labs, Inc. Glossary of Fiber Optic Terms
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40/100/400
40/100 Gigabit Ethernet:
40GbE and 100GbE are rates of Ethernet protocol (40 and 100) for transmitting data over fiber optic networks. The technology was first defined by the IEEE 802.3ba-2010 standard.40GBASE-LR4 QSFP+:
40GbE QSFP+ LR4 (long range) optical module transmits 40Gb Ethernet over four 10G optical signals and multiplexes them into a single fiber over a distance of 10km. The module has a built-in mux/demux and LC interface.40GBASE-SR4 QSFP+:
40GbE QSFP+ SR4 (short range) optical module transmits 40Gb Ethernet over four separate 10G optical signals over a distance of 150m. It uses four wavelengths in the 850nm, with the mux/demux built-in to the modules.100G OIF Coherent:
A 100G long haul DWDM non-pluggable transceiver module modulated as 100G PM-QPSK, with coherent detection on the receive side. This is a full C-band, multi source agreement (MSA) module with single tunable 50GHz, and can reach approximately 2000km without the need for dispersion compensation. The module supports OTU4, usually with internal soft decision forward error correction (SD FEC) capability implemented using a powerful digital signal processing (DSP). The framework for this optical module was defined by the Optical Internetworking Forum (OIF).400ZR / OIF ZR:
400ZR / OIF ZR is an Ethernet-based networking interface defined by the Optical Internetworking Forum (OIF). Called an Implementation Agreement, it specifies 400G optical transmission over a single wavelength for dense wavelength division multiplexing (DWDM) deployments. 400ZR targets edge and relatively short reach DCI applications of up to 120km. The combination of 400G per wavelength and DWDM provides networks with very high capacity interconnect bandwidth.Adapter:
A mechanical media termination device designed to align and join fiber optic connectors. Often referred to as a coupling, bulkhead or interconnect sleeve.AGC:
Automatic gain control (AGC) in optical networking refers to a method of automatically adjusting the gain of the receiver to maintain a constant average output level of the wavelength stream in an optic fiber. AGC is usually used in EDFAs as one of two automatic adjustment methods.Analog:
A format that uses continuous physical variables such as voltage amplitude or frequency variations to transmit information.Aramid Yarn:
Strength elements that provide tensile strength and provide support and additional protection of the fiber bundles. Kelvar is a particular brand of aramid yarn.Armor:
Additional protective element beneath outer jacket to provide protection against severe outdoor environments. Usually made of plastic-coated steel, it may be corrugated for flexibility.Attenuation:
Attenuation in optical networks refers to a loss of intensity of the light signal over distance in a fiber optic cable. Measured in dB/km, attenuation is a significant factor when planning an optical network and is taken into consideration by any optical engineer. In order to compensate for attenuation, optical amplifiers are often used.Attenuation Coefficient:
The rate of optical power loss with respect to distance along the fiber, usually measured in decibels per kilometer (dB/km) at a specific wavelength. The lower the number, the better the fibers attenuation. Typical multimode wavelengths are 850 and 1300 nanometers (nm); singlemode wavelengths are 1310 and 1550 nm. Note: When specifying attenuation, it is important to note whether the value is average or nominal.Backbone Cabling:
The portion of premises telecommunications cabling that provides connections between telecommunications closets, equipment rooms and entrance facilities. The backbone cabling consists of the transmission media (optical fiber cable), main and intermediate cross-connects, and terminations for the horizontal cross-connect, equipment rooms, and entrance facilities. The backbone cabling can further be classified as campus backbone (cabling between floors or closets within a building).Bandwidth:
Measure of the information-carrying capacity of an optical fiber. Note: This term is often used to specify the normalized modal bandwidth (MHz·km) of a multimode fiber. See Dispersion for single-mode fibers.Bandwidth-Distance Product:
The information-carrying capacity of a transmission medium is normally referred to in units of MHz·km. This is called the bandwidth-distance product or, more commonly, bandwidth. The amount of information that can be transmitted over any medium changes according to distance. The relationship is not linear, however. A 500 Mhz·km fiber does not translate to 250 Mhz for a 2 kilometer length or 1000 MHz for a 0.5 kilometer length. It is important, therefore, when comparing media to ensure that the same units of distance are being used.Buffering:
(1) A product material extruded directly on the fiber coating to protect it from the environment (tight-buffered):
(2) extruding a tube around the coated fiber to allow isolation of the fiber from stresses in the cable (buffer tubes).Buffer Tubes:
Extruded cylindrical tubes covering optical fiber(s), used for protection and isolation. See Loose Tubes.Building Backbone:
The portion of the backbone cabling within a building (floor-to-floor or closet-to-closet). See Backbone Cabling.Bundle:
Many individual fibers contained within a single jacket or buffer tube. Also, a group of buffered fibers distinguished in some fashion from another grouping the same cable core.Cable:
An assembly of optical fibers and other material providing mechanical and environmental protection.Cable Assembly:
Optical fiber cable that has connectors installed on one or both ends. General use of these cable assemblies includes the inter connection of optical fiber cable systems and opto-electronic equipment. If connectors are attached to only one end of a cable, it is known as a pigtail. If connectors are attached to both ends, it is known as a jumper or patch cord.Cable Bend Radius:
Cable bend radius during installation infers that the cable is experiencing a tensile load. Free bend infers a smaller allowable bend radius, because it is at a condition of no load.C-band:
C-band in optical networking refers to a section of wavelengths (colors) that ranges between 1530nm to 1565nm.Campus Backbone:
The portion of the backbone cabling between buildings. See Backbone Cabling.Central Member:
The center component of a cable. It serves as an anti-buckling element to resist temperature-induced stresses. Sometimes serves as a strength element. The central member material is either steelCentralized Cabling:
A cabling topology used with centralized electronics, connecting the optical horizontal. Cabling with the building backbone cabling, passively in the telecommunications Closet.CFP:
The century form factor pluggable (CFP) is an optical transceiver module typically used for 100GbE and 100G OTU4 OTN data rates, as as a client interface or an uplink coherent interface. The optical interface supports a number of lanes, reaching 10km/40km over single mode (SM) fiber, and 100m over multimode (MM) fiber. The electric interface on the host side comprises 10 lanes of 10G. CFP supports LR4, ER4 and SR10 optical interfaces on the client side, and coherent tunable transceiver on the DWDM line side, reaching over 1000km without the need for DCM or regeneration sites.CFP2:
The century form factor pluggable 2 (CFP2), is an optical transceiver module which supports 100GbE and OTN OTU4 data rates. It is a smaller form factor than the CFP and consumes less power, enabling higher port density. The electrical interface depends on the application, for example, 10 lanes of 10G or 4 lanes of 25G. The optical interface is usually 4 lanes of 25G over a single mode fiber.CFP2-ACO:
The century form factor pluggable 2 analog coherent optics (CFP2-ACO) is a transceiver module coupled with a DSP on the host board, for 100G and 200G metro systems. The transceiver is tunable and pluggable, providing cost and power consumption reduction for 100G/200G single wavelength coherent DWDM applications. The transceiver also facilitates pay-as-you-grow benefits, as bandwidth is easily increased by adding transceivers. The CFP2-ACO is popular with system designers because of its multi-source agreement (MSA) form factor, increased bandwidth density, and interoperability with multiple optical transceiver vendors. The CFP2-ACO is dual-rate and enables transmission distance as high as 2500km in 100G DQPSK modulation or 600km in QAM 200G modulation.CFP2-DCO:
The century form factor pluggable 2 digital coherent optics (CFP2-DCO) is a DWDM module that supports 100G and 200G data rates in DCI and long-haul applications. The CFP2-DCO integrates the coherent DSP within the module. The CFP2-DCO a plug-and-play module enables simple and efficient deployment. The module also has digital signal processors which enable users to configure the module in real-time, for changing application needs.Cladding:
The material surrounding the core of an optical waveguide. The cladding must have a lower index of refraction to keep the light in the core.Coating:
A material put on a fiber during the drawing process to protect it from the environment and handling.Common Criteria:
The Common Criteria (CC), formalized as ISO/IEC 15408, defines a hierarchical framework of security concepts and terminology. This allows consumers, developers and regulatory groups to create standardized sets of security threats, objectives, requirements and assurance measures. The CC is a technical basis for the Common Criteria Recognition Arrangement (CCRA) international agreement, which ensures that Products can be evaluated by competent and independent licensed laboratories to determine the fulfilment of particular security properties. The CC is the driving force for the widest available mutual recognition of secure IT products.Composite Cable:
A cable containing both fiber and copper media per article 770 of the National Electrical Code (NEC).Conduit:
Pipe or tubing through which cables can be pulled or housed.Connecting Hardware:
A device used to terminate an optical fiber cable with connectors and adapters that provides an administration point for cross-connecting between cabling segments or interconnecting to electronic equipment.Connector:
A mechanical device used to align and join two fibers together to provide a means for attaching to and decoupling from a transmitter, receiver, or another fiber (patch panel). Commonly used connectors include the 568SC (Duplex SC), ST compatible, FDDI, ESCON, SMA 905/906, Biconic, FC or D4.Connector Panel:
A panel designed for use with patch panels; it contains either 6, 8 or 12 adapters pre-installed for use when field-connectorizing fibers.Connector Panel Module:
A module designed for use with patch panels; it contains either 6 or 12 connectorized fibers that are spliced to backbone cable fibers.Core:
The central region of an optical fiber through which light is transmitted.Coupling:
See AdapterCPE:
Customer premises equipment (CPE) is carrier or service provider equipment that is located on the customer's premises (physical location) rather than on the carrier or service provider premises, network, or in between. The equipment can be owned by the customer or by the carrier/provider.CPRI:
Common Public Radio Interface (CPRI™) is a digital radio frequency protocol used in transporting radio signals over fiber in mobile networks. It is commonly used in fronthaul networks. The following CPRI rates are standardized: 614.4Mbit/s, 1228.8 Mbit/s, 2457.6 Mbit/s, 3072.0 Mbit/s, 4915.2 Mbit/s, 6144.0 Mbit/s, 9830.4 Mbit/s.Crosstalk
Crosstalk in optical networks is where information from one channel crosses over into another channel, causing distortion in the transmitted signal. PacketLight's solutions eliminate crosstalk in WDM networks by using independently colored channels (wavelengths).CWDM:
Coarse wavelength division multiplexing (CWDM) is one of two types of WDM multiplexing technology (DWDM is the other). CWDM offers up to 18 channels (wavelengths) per each fiber pair, making it a good initial entry point for many organizations. CWDM operates in the spectral range of 1270nm to 1550nm, and each wavelength typically supports up to 10Gb Ethernet, 16G Fibre Channel, and STM-1/STM-4/STM-16. CWDM is primarily used in applications of up to 80km, as the signal waves are spaced further apart and cannot support amplification.CXP:
The century small form-factor pluggable (CXP) is an optical transceiver module for transporting 100Gb Ethernet in short distances of up to 100m. The electrical side has 12 lanes of 10G, and hte optical side has 12 lanes of 10G over 12 paralel multimode fibers. In case of a 100G network, only 10 lanes are used. The small form factor of the CXP and its low power consumption, make it a low cost 100G interface.Dark Fiber:
In optical networking, dark fiber is unused (or unlit) fiber, that is ready for use.DCM:
Dispersion compensation modules (DCM) are used in long spans of transmission fiber to maintain the integrity of the signal. The DCM provides fixed and tunable dispersion compensation. The DCM is usually placed between two fiber amplifiers, or at the beginning or end of the link, and is installed using the module's input and output fiber connectors.Decibel:
Unit for measuring the relative strength of light signals. Normally expressed in dB, it is equal to one-tenth the common logarithm of the ratio of the two levels. Expressed in dBm when a power level is compared to a milliwatt.Dielectric:
Non-metallic and, therefore, non-conductive. Glass fibers are considered dielectric. A dielectric cable contains no metallic components.Demarcation Point:
Demarcation point is the physical point in which the network of the carrier or service provider ends and the network of the customer begins. It defines where the carrier's / service provider's responsibility for the network ends. It can also indicate the demarcation (or defining point) between transport Layer-2/3 and the DWDM/OTN Layer-1 infrastructure. The demarcation point includes performance monitoring, loopback and other diagnostic means to isolate issues and detect network faults. In the demarcation point, either the 3R (retiming, reamplifying, and regeneration) or the OTN FEC, ensure an error-free optical layer.Demultiplexer (Demux):
A demultiplexer (demux) is a device that receives an input signal containing multiple signals and splits it into multiple signals while maintaining the integrity of each signal. In optical networks, the demultiplexer separates one optical signal containing multiple colored signals, into separate channels.Differential Mode Delay (DMD):
Occurs in some non-laser tested multimode fibers when they are used with laser sources. The result is signal distortion, which limits the distance Gigabit LX signals can be transmitted on multimode fibers.Digital:
A data format that uses two physical levels to transmit information corresponding to 0s and 1s. A discrete or discontinuous signal.Dispersion:
In optical networking wavelength velocity (or speed) is dependent on its frequency. Changes in frequency cause a delay in the light pulse, degrading the optical signal over long distances. Some data rates, such as 10Gb Ethernet, are more sensitive to dispersion than others. To prevent dispersion and ensure the integrity of the optical signal, dispersion compensation modules (DCM) are placed strategically along the optical link.DR4 (400GBase-DR4):
400 QSFP-DD DR4 optical module transmits 100Gb Ethernet over four separate 100G optical signals, over a distance of 500m. The module interface is MPO-12.DSP:
Digital signal processing (DSP) is used to improve the accuracy and reliability of digital communications, and is an important component in optical coherent transmission for high-speed links over 100G. It is able to differentiate between signals and noise, significantly improving the sensitivity of the receiving unit, especially noticeable when noise competes with a signal. The DSP performs modulation of the optical signal and compensates for fiber dispersion.DWDM:
Dense wave division multiplexing (DWDM) is a type of WDM multiplexing technology, which combines multiple wavelengths into a single optical fiber, facilitating very high utilization of the fiber. DWDM architecture enables fitting multiple wavelengths on a single fiber and supports long haul, metro and DCI applications with capacities of 10G/100G/200G/400G per wavelength. DWDM systems can support ultra-long haul applications of thousands of kilometers using amplifiers.EDFA:
Erbium-doped fiber amplifier (EDFA) is an optical device that amplifies optical signals without converting them to electrical signals, enabling them to reach longer distances (between 80km and 200km) without intermediary nodes. EDFAs are commonly used in DWDM networks. PacketLight offers three types of EDFAs: inline, boosters, and pre-amplifiers.Encryption:
Optical encryption solves the need for data security over DWDM and OTN links, and answers requirements and regulations that have been put into place to maintain confidentiality, data integrity, and authentication. Implementing encryption at the optical layer (Layer-1) of the signal has several advantages. Layer-1 supports multiple client protocols, does not allow for omissions and is easier to deploy. Most importantly, encryption on Layer-1 is transparent to the traffic at full bandwidth, without degradation to the link. The optical layer can also detect tapping attempts as it constantly monitors the power levels of the DWDM channels and alerts of any change.Entrance Facility:
An entrance to a building for both public and private network service cables, including the entrance point at the building wall and continuing to the entrance room or space.Equipment Room:
A centralized space for telecommunications equipment that serves the occupants of a building. An equipment room is considered distinct from a telecommunications closet because of the nature or complexity of the equipment.ER4 (100GBase-ER4):
100G QSFP28 ER4 (extended range) optical module transmits 100Gb Ethernet over four 25G optical signals, and multiplexes them into a single fiber over a distance of 40km. It uses four wavelengths in the 1300nm with the mux/demux built-in to the modules. The module interface is LC, and it supports 100G OTN OTU4.ESCON:
ESCON (Enterprise Systems Connections) is a method of data connection proprietary to IBM. The method utilizes a half-duplex optical fiber with serial interface. It is used mainly for connecting peripheral devices (printers, tape drives, disk storages) to IBM's mainframe computers. PacketLight's solutions support ESCON based connectivity.Ethernet:
Ethernet is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1983 as IEEE 802.3. Ethernet has since been refined to support higher bit rates, a greater number of nodes, longer link distances, and retains significant backward compatibility.FEC:
Forward error correction (FEC) refers to an error-controlling mechanism in data transmission. FEC allows the sender to add redundant data to the transmitted information, aiding the receiver to identify and correct any errors in the data. FEC boosts the network optical performance by a factor of at least 4 (6dB coding gain), and is a major feature of the OTN network. It is standardized by both ITU-T G.709 and ITU-T G.975 specifications.Ferrule:
A mechanical fixture, generally a rigid tube, used to protect and align a fiber in a connector. Generally associated with fiber optic connectors.Fiber:
Thin filament of glass. An optical waveguide consisting of a core and a cladding that is capable of carrying information in the form of light.Fiber Bend Radius:
Radius a fiber can bend before the risk of breakage or increase in attenuation occurs.Fibre Channel (FC):
Fibre Channel (FC) is a standardized gigabit transport technology utilized in storage devices and storage networking. FC transport rates include 1/2/4/8/10/16/32G. PacketLight supports all these rates over long distances.Fiber Optics:
Light transmission through optical fibers for communication or signaling.FICON:
FICON (fiber connection) is a proprietary IBM Fibre Channel protocol used primarily in mainframe computers. PacketLight products support FICON FC protocol.FIPS:
Federal Information Processing Standards (FIPS) were developed by the US federal government for use in computer systems by non-military government agencies and government contractors. One of the main topics of the FIPS standards is computer security. PacketLight encryption devices are compliant with FIPS 140-2 Level 2 requirements for encryption and data security.FOTP:
Fiber Optic Test Procedures. Defined in TIA/EIA Publication Series 455.Fresnel Reflection Losses:
Reflection losses that are incurred at the input and output of optical fibers due to the differences in refraction index between the core glass and immersion medium.FR4 (400GBase-FR4):
400G QSFP-DD FR4 optical module transmits 100Gb Ethernet over four optical signals, and multiplexes them into a single fiber over a distance of 2km. The module has a built-in mux/demux and LC interface.Fusion Splice:
A permanent joint produced by the application of localized heat sufficient to fuse or melt the ends of the optical fiber, forming a continuous single fiber.GDPR:
The General Data Protection Regulation ((EU) 2016/679), is designed to strengthen and unify data protection for all individuals within the EU, including export of personal information outside the EU. The GDPR stipulates that businesses must receive consent from individuals to collect personal details, and this consent can be withdrawn at any given time, with the information permanently deleted. The GDPR includes small to medium enterprises (SME) and large businesses. It took effect in May 2018, replacing the 1995 data protection directive (Directive 95/46/EC).Gigahertz (GHz):
A unit of frequency that is equal to one billion cycles per second, 109 Hertz.Graded-Index:
Fiber design in which the refractive index of the core is lower toward the outside of the fiber core and increases toward the center of the core; thus, it bends the rays inward and allows them to travel faster in the lower index of refraction region. This type of fiber provides higher bandwidth capabilities for multimode fiber transmission.Horizontal Cabling:
That portion of the telecommunications cabling that provides connectivity between the horizontal cross-connect and the work-area telecommunications outlet. The horizontal cabling consists of transmission media, the outlet, the terminations of the horizontal cables, and horizontal cross-connect.Horizontal Cross-Connect (HC):
A cross-connect of horizontal cabling to other cabling, e.g., horizontal, backbone, equipment.Hybrid Cable:
A fiber optic cable containing two or more types of fiber, such as 62.5 um multimode and single-mode.Index-Matching Fluid:
A fluid with an index of refraction close to that of glass that reduces reflections caused by refractive-index differences.Index of Refraction:
The ratio of light velocity in a vacuum to its velocity in a given transmission medium.Insertion Loss:
Insertion loss of a component is one of the main factors influencing optical link budget. It is expressed in dB and defined as 10*log (Pout/Pin of a signal of an optical component), where Pout = Signal Power at Output, and Pin = Signal Power at Input. Optical amplifiers are typically used to compensate for insertion losses along the optical path.ITU:
International Telecommunication Union (ITU) is a part of the UN family responsible for managing communication and technology issues for world governments and corporate communities. ITU is best known for its activities in establishing standards for technology and telecommunication equipment, monitoring the international radio-frequency spectrum, and spreading the technology around the world. ITU standards are recognized worldwide. PacketLight is on the ITU-approved telecom equipment list.Intermediate Cross-Connect (IC):
A secondary cross-connect in the backbone cabling used to mechanically terminate and administer backbone between the main cross-connect and horizontal cross-connect.Jumper:
Optical fiber cable that has connectors installed on both ends. See cable assembly.kpsi:
A unit of force per area expressed in thousands of pounds per square inch. Usually used as the specification for fiber proof test, e.g., 100 kpsi.Kilometer (km):
One thousand meters, or approximately 3,281 feet. The kilometer is a standard unit of length measurement in fiber optics. Conversion is 1 ft = 0.3048 m.LASER Diode:
Light Amplification by Stimulated Emission of Radiation. An electro-optic device that produces coherent light with a narrow range of wavelengths, typically centered around 780nm, 1310nm or 1550nm. Lasers with wavelengths centered around 780nm are commonly referred to as CD lasers.L-band:
L-band in optical networking refers to a section of wavelengths (colors) of light that ranges between 1565nm to 1625nm.LAN:
A local area network (LAN) is a group of devices that share a common communications line. The LAN network is usually concentrated in a relatively small area such as a single room, building or group of buildings.Latency:
Latency in optical networking refers to the time it takes for a signal to reach from the start point to the end point. This timeframe is usually measured in milliseconds and is especially important in applications that require speedy transfer of information such as video streaming and financial transactions.Layer-1, Layer-2, Layer-3
In fiber optic networks, networking standards are separated into layers:
Layer-1 - the physical layer - electrical and optical hardware where the electrical signals are converted into light, so they can be transported over fibers for short distances inside the data center or over long haul DWDM optical networks.
Layer-2 - the data link layer - handles errors in the physical layer, provides flow control, and frame synchronization.
Layer-3 - the network layer - switching and routing data from node to node.Light Emitting Diode (LED):
A semiconductor device used to transmit light into a fiber in response to an electrical signal. It typically has a broad spectral width.Link:
A telecommunications circuit between any two telecommunications devices, not including the equipment connector.Loose Tube Cable:
Type of cable design whereby coated fibers are encased in buffer tubes, offering excellent fiber protection and segregation.LR4 (100GBASE-LR4):
100G QSFP28 LR4 (long range) optical module transmits 100Gb Ethernet over four 25G optical signals, and multiplexes them into a single fiber over a distance of 10km. It uses four wavelengths in the 1300nm, with the mux/demux built-in to the modules. The module module interface is LC, and it supports 100G OTN OTU4.LR8 (400GBase-LR8):
400G QSFP-DD LR8 (long range) optical module transmits 400Gb Ethernet over eight 50G optical signals, and multiplextes them into a single fiber over a distance of 10km. It uses eight wavelengths in the 1300nm, with the mux/demux built-in to the modules. The module interface is LC.Main Cross-Connect (MC):
The centralized portion of the backbone cabling used to mechanically terminate and administer the backbone cabling, providing connectivity between equipment rooms, entrance facilities, horizontal cross-connects, and intermediate cross-connects.MDPE:
Abbreviation used to denote medium density polyethylene. A type of plastic material used to make cable jacketing.Mechanical Splicing:
Joining two fibers together by permanent or temporary means (vs. fusion splicing or connectors) to enable a continuous signal. The CamSplice is a good example of a mechanical splice.Megahertz (MHz):
A unit of frequency that is equal to one million cycles per second.Mesh Network:
Mesh network is a network topology in which some or all the network nodes are connected directly with no dependency on a single node. The nodes are connected to as many other nodes as possible and work in cooperation to efficiently route data to and from clients, with every node participating in the relay of information. Mesh topology increases network resilience in case of a failure of a node or connection.Metro Ethernet:
Metro Ethernet is an Ethernet-based standard often used to connect branch offices and other homogeneous organizations to internal Internet (Intranet). The Metro Ethernet computer network covers a large metropolitan area in order to connect users and businesses to the Internet.Micrometer (um):
One millionth of a meter; 10-6 meter. Typically used to express the geometric dimension of fibers. e.g. 62.5 um.Mode:
A term used to describe an independent light path through a fiber, as in multimode or single-mode.Mode Conditioning Patch Cords (MCP):
Mode Conditioning Patch Cords are used with Gigabit LX electronics when non-laser tested multimode backbone fibers are to be used. A splice in the patch cord transmit fiber offsets the laser launch to avoid DMD problems. Corning INFINICOR CL fiber cables are laser tested/qualified and do not require the use of mode conditioning patch cords. See differential Mode Delay (DMD).Mode Field Diameter:
The diameter of the one mode of light propagating in a single-mode fiber. The mode field diameter replaces core diameter as the practical parameter in single-mode fiber.Modulation:
Coding of information onto the carrier frequency. This includes amplitude, frequency or phase modulation techniques.Multifiber Cable:
An optical fiber cable that contains two or more fibers.Multimode Fiber:
Multimode fiber has a larger diameter core for light path than single mode fiber. In multimode fiber, light propagates in multiple modes, each taking a slightly different path through the fiber and travelling at a slightly different velocity for a given fiber length. The multimode optical light source is based on low cost LEDs and electronics, making multimode fiber networks a much more cost-effective optical connectivity solution. However, the low light concentration makes this solution applicable for short distances of between 300m and 550m. PacketLight’s WDM solutions enable to extend multimode fiber capabilities beyond the 550m limitations of the 62.5µm (OM1) multimode fiber, to 2km or more depending on fiber quality and service type.Multiplexer: (Mux)
A multiplexer (mux) is an electronic device that combines multiple electronic input signals into a single output signal, while maintaining the integrity of each signal. In optical networks, multiplexers unite different data rates coded in different colors, into one signal that can be transported over single or dual fiber without degrading or altering the signals.Multi-User Outlet:
A telecommunications outlet used to serve more than one work area, typically in open-systems furniture applications.Muxponder:
In optical networks, muxponders are used to aggregate multiple types of services into a single 10G/100G/200G/400G wavelength/uplink using OTN mapping. Muxponders utilize ITU OTN (optical transport network, see below) protocol and mapping to reduce the number of wavelengths needed to transport data and increase spectral efficiency of the network. They are the preferred choice for maximizing fiber capacity and for enabling simple future network growth. Services aggregated include: Ethernet, SONET/SDH, Fibre Channel, HD/SD-SDI, and OTU2/3/4.Nanometer:
A unit of measurement equal to one billionth of a meter; 10-9 meters. Typically used to express the wavelength of light, e.g., 1300 nm.National Electrical Code (NEC):
Defines building flammability requirements for indoor cables. Note: Local codes take precedence but may refer to or require compliance to the NEC.Native Video Transport:
Video is typically transported over metro networks. For example, live feeds to a TV studio, or within campus and enterprise networks. Native broadcast video transport transport delivers high quality video without compression, with low latency and reduced cost. Native video transport applications includes broadcast studios, sports stadiums, digital production and broadcast facilities and stations (TV, cinema). Video interfaces include 3G HD-SDI, HD-SDI, SD-SDI, DVB-ASI, FE/GbE, FC/FICON, SONET/SDH.NGN:
Next Generation Networking (NGN) is a term commonly used to describe packing voice, data, and video information into the same data packets using OTN encapsulation. NGN architecture is constantly evolving in the fields of telecommunication and access. PacketLight solutions support NGN architecture and serve as a basis for developing its infrastructure.NMS:
Network Management System (NMS) provides full fault, configuration, accounting, performance and security functionality to the system it is “attached” to, and adheres to relevant industry standards. PacketLight LightWatchTM is a multi-platform Java-based NMS, that controls PacketLight devices on the network and ensures smooth end-to-end provisioning. LightWatch is compliant with telecommunications management network (TMN) standards.Numerical Aperture (NA):
The number that expresses the light gathering ability of a fiber. Related to acceptance angle.OADM:
An optical add-drop multiplexer (OADM) is a passive optical device used in WDM networks and enables to add and separate (drop) single or multiple wavelengths (channels) from a stream of light on a single fiber while the remaining wavelengths continue through to the their destination.Open ROADM:
Open ROADM is an interoperability specification for the 400G DWDM pluggable module, defined by multi-source agreement (MSA). It focuses on long reach (>120km), advanced forward error correction (Open FEC) and supports 100G, 200G, 300G, and 400G data rates.OpenZR+:
OpenZR+ is a merge of two standards: ZR (by OIF) and Open ROADM (by MSA), which combines the best features from each standard and enables high performance pluggable modules and multi-vendor interoperability. The target reach of the OpenZR+ standard is 1200km. More than 10 times the reach of 400ZR.Optical Amplifier:
An optical amplifier amplifies the optical signal without first converting it to an electrical signal. Amplifiers are important in fiber optic systems as they eliminate the need for repeaters in long haul networks, which may include several amplification sites along the link. Optical amplifiers can amplify the entire C-band spectrum (up to 96 wavelengths) simultaneously. PacketLight offers the two main types of optical amplifiers: Erbium-doped fiber amplifier (EDFA), and Raman amplifiers.Optical Carrier (OC):
Optical carrier (OC) transmission rates are standardized specifications of transmission bandwidth for digital signals that can be carried on synchronous optical networking (SONET) networks. There are several levels of OC: OC-1, OC-3, OC-12, OC-24, OC-48, OC-192.Optical Circulator:
A three or four-port optical device designed so that light entering any port exists from the next port. Curculators are used to separate optical signals that travel in opposite directions in an optical fiber.Optical Fiber:
See Fiber.Optical Isolator:
Isolator, or optical diode, is an optical component which allows the transmission of light in only one direction.Optical Time Domain Reflectometer (OTDR):
An instrument that measures transmission characteristics by sending a series of short pulses of light down a fiber and providing a graphic representation of the backscattered light.Optical Transmitter:
An optical transmitter is a device that sends data and information to a receiver through a fiber optic cable. A transmitter is usually connected to a power supply and is part of an active solution for fiber optic networks.OSC:
The optical supervisory channel (OSC) is an additional wavelength which is usually outside the EDFA (see above) band, which carries information about the optical signal as well as remote conditions at the optical terminal or EDFA site. It is also normally used for remote software upgrades and user network management information.OTN:
Optical transport network (OTN) is an optical mapping layer for a number of different services over the same common frame and rate structure, enabling a single optical transport network regardless of the native client signal. OTN relies on ITU-T G.709 digital wrapper specification to transparently encapsulate client signals and provide faster troubleshooting and superior SLA monitoring capabilities. OTN includes the additional benefit of forward error correction (FEC) to boost the network optical performance by a factor of at least 4 (6dB coding gain).OTU4:
OTU4 is an OTN rate that transports a 100Gb Ethernet signal. It is defined in the ITU-T G.709 standard.PE:
Abbreviation used to denote polyethylene. A type of plastic material used for outside plant cable jackets.PVC:
Abbreviation used to denote polyvinyl-chloride. A type of plastic material used for cable jacketing. Typically used in flame-retardant cables.PVDF:
Abbreviation used to denote polyvinyl-difluoride. A type of material used for cable jacketing. Often used in plenum-rated cables.Pigtail:
Optical fiber cable that has a connector installed on one end. See Cable Assembly.PIN Diode:
A semiconductor device used to convert optical signals to electrical signals in a receiver.Plenum:
An air-handling space such as that found above drop-ceiling tiles or in raised floors. Also, a fire-code rating for indoor cable.Point-to-Point:
A point-to-point network topology refers to a bi-directional connection between two endpoints or nodes.QSFP+:
Quad small form factor pluggable (QSFP) is an optical transceiver usually used for 40G links in data centers, and is often used to save panel space by replacing 4 x SFP+.The optical and electrical interfaces utilize 4 lanes of 10G. The optical interface can be 4 lanes over a single fiber (single mode) or 4 lanes over 4 fibers (multimode). QSFP+ supports short reach (SR), long reach (LR) and extender reach (ER), with each providing a cost/reach tradeoff.QSFP28:
Quad small form factor pluggable 28 (QSFP28) is a hot-pluggable transceiver module designed for 100G data rate. It integrates 4 transmitter and 4 receiver channels. "28" refers to each lane carrying up to 28G data rate. Depending on the transceiver used, the QSFP28 typically operates at 4x25G for 100GbE but it will evolve to 2x50G or 1x100G over time as technology progresses. The QSFP28 has the same mechanical footprint and host board connector designs as the QSFP+ optical module, so it also supports 40GbE or breakout into 4x10GbE. There are three main types of QSFP28: LR4 for 10km, SR4 for 100m, and CWDM4 for 2km. The small footprint and low power consumption of the QSFP28 enable high density and capacity in 1U optical and switching systems, which facilitates cost reduction.QSFP-DD:
The quad small form factor hot pluggable (QSFP) double density (DD) transceiver module is designed for 400G data rate. It integrates 8 transmitter and 8 receiver electrical channels. DD means the doubling of the number of high-speed electrical interfaces that the module supports compared with a standard QSFP28 module. Each lane carries 50Gb/s by PAM4 modulation technology, achieving 400G network transmission, suitable for high-performance computing data centers and cloud networks. Depending on the transceiver used, the QSFP-DD typically operates at 8x25G NRZ modulation for 200GbE or 8x50G PAM4 modulation. The QSFP-DD has a similar mechanical footprint to the QSFP28, but the host board connector design is different (double the number of pins). The main QSFP-DD types are: CDWM LR4 for 10km, SR8 for 100m (MMF), DR4 for 500m and CWDM FR4 for 2km.Raman Amplifier:
Raman amplification is achieved by nonlinear interaction between the signal and a pump laser within an optical fiber. The Raman pump power is higher than in the Erbium-doped fiber amplifier (EDFA), enabling the signal to travel further (between 200km and 300km, depending on fiber attenuation). The Raman amplifier increases the effective distance and significantly improves OSNR.Receiver:
An electronic package that converts optical signals to electrical signals.Reflectance:
The ratio of power reflected to the incident power at a connector junction or other component or device, usually measured in decibels (dB.) Reflectance is stated as a negative value, e.g., -30 dB. A connector that has a better reflectance performance would be a -40 dB connector or a value less than -30dB. The terms return loss, back reflection, and reflectivity are also used synonymously in the industry to describe device reflections, but they are stated as positive values.Repeater:
A device used to regenerate an optical signal to allow an increase in the system length.Return Loss:
See Reflectance.Riser:
Pathways for indoor cables that pass between floors. It is normally a vertical shaft or space. Also a fire-code rating for indoor cable.ROADM:
A reconfigurable optical add-drop multiplexer (ROADM) is an optical device that allows wavelengths to be added or dropped from a WDM transport network without first converting them into electrical signals. The ROADM is remotely configurable and allows automatic power balancing.Scattering:
A property of glass that causes light to deflect from the fiber and contributes to optical attenuation.Single-Mode Fiber:
There are two types of fibers in optical networking today: single mode and multimode. Single mode (SM) optical fiber has a smaller core diameter, which forces all the energy in a light signal to travel in the form of a single mode, dramatically increasing the bit rate over distance. As it has a laser-based light source, SM fiber requires more expensive and precise electronics for data transport.SONET & SDH:
Synchronous optical networking (SONET) and synchronous digital hierarchy (SDH) are standardized multiplexing protocols that transfer multiple streams of bit over the optical fiber. SONET is the standard used in the US and Canada, and SDH is the standard used in the rest of the world. SONET rates are designated by optical carrier (OC), OC-1/3/12/24/48/192. SDH rates are designated by synchronous transport module (STM) STM-1/4/16/64.Splice Closure:
A container used to organize and protect splice trays. Typically used in outside plant environment.Splice Tray:
A container used to secure, organize and protect spliced fibers.Splicing:
The permanent joining of bare fiber ends to another fiber. See Fusion Splice and Mechanical Splicing.SR4 (100GBase-SR4):
100G QSFP28 SR4 (short range) optical module transmits 100Gb Ethernet over four separate 25G optical signals, over a distance of 100m. It uses four wavelengths in the 850nm, each carrying 25G in four parallel fibers. The module interface is MPO, and it supports 100G OTN OTU4.SR8 (400GBase-SR8):
400G QSFP-DD SR8 (short range) optical module transmits 400Gb Ethernet over eight separate 50G optical signals, over a distance of 100m (OM4). It uses eight wavelengths of 850nm, each carrying 50G in eight parallel fibers. The module interface is MPO.STM:
Synchronous transport module (STM) is the standard for transmitting SDH signal over fiber optic network. There are several levels of STM: STM-1, STM-4, STM-16 and STM-64.Storage Area Network (SAN):
A storage area network (SAN) is a system of storage devices incorporated into a one data storage unit and transparently connected to the local area network (LAN). It can usually be accessed only by a system administrator.Telecommunications Closet (TC):
An enclosed space for housing telecommunications equipment, cable terminations, and cross-connect between the backbone and horizontal cabling.Tight-Buffered Cable:
Type of cable construction whereby each glass fiber is tightly buffered by a protective thermoplastic coating to a diameter of 900 micrometers. Increased buffering provides ease of handling and connectorization.Transponde:r
Optical transponders send and receive the optical signal from a fiber. A transponder is typically characterized by its data rate and the maximum distance the signal travels. Transponders convert the incoming optical signal into a pre-defined optical wavelength, by first converting it to an electrical signal and performing the 3R. The electrical signal then drives the laser, generating the optical signals. Transparent transponders implement 3R functionality for shorter distances of up to 200km, and OTN transponders add the encapsulation of the service into OTN with FEC, enabling the signal to transport over thousands of kilometers without the need for regenerators.Transmitter:
An electronic package used to convert an electrical information-carrying signal to a corresponding optical signal for transmission by fiber. The transmitter is usually a light emitting diode (LED) or laser diode.Wavelength:
The distance between two successive points of an electromagnetic waveform, usually measured in nanometers (nm).WDM
Wavelength division multiplexing (WDM) is a technology of optical networking used to combine multiple optical signals into one, and transfer it over a single fiber, using multiplexing and demultiplexing to achieve the desired effect. WDM technology increases capacity while significantly decreasing CAPEX and OPEX of optical networking. It also enables bi-directional communication. There are two types of WDM technology: coarse WDM (CWDM) and dense WDM (DWDM).Work-Area Telecommunications Outlet:
A connecting device located in a work area at which the horizontal cabling terminates and provides connectivity for work-area cords.Zero-Dispersion Wavelength:
Wavelength at which the chromatic dispersion of an optical fiber is zero. Occurs when waveguide dispersion cancels out material dispersion.
A
APC:
Automatic power control (APC) in optical networking refers to a method of automatically adjusting the power (or attenuation) of the receiver to maintain constant average output level for wavelength stream in a fiber optic cable. APC is usually used in EDFAs as one of two automatic adjustment methods.
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