Glossary

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There are currently 111 terms in this directory
5G
Fifth-generation technology standard and architecture for mobile networks. It uses higher frequencies, and more (but smaller) cell sites to provide greater bandwidth and lower latency. It is also expected to enable a considerable increase in Internet-of-Things applications.
5G

Access Network
The section of a telecom network that connects subscribers to the plant of their immediate service provider.

Active Component
A part of a photonic circuit that requires external electric power to control or modify optical signals. Examples: lasers, modulators, photodetectors

Analog Signal
A continuous signal that represents (i.e. another physical quantity (i.e. that is "analogous" to the other quantity).

Attenuation
The degradation of an optical signal over distance. Depending on the medium (air, optical fiber) this degradation will vary.

Backbone (Core Network)
The part of a network that interconnects different networks and sites of a network provider.

Backhaul
The part of a 5G network that connects the centralized units (CU) of the radio network to the core network of the provider.

Bits Per Second
A common measure of data speed for telecommunications equipment and links.

C-Form Factor Pluggable
A pluggable transceiver form factor (significantly larger than an SFP) that developed originally for 100G transmission. It was been replaced over time by the smaller SFP and QSFP form factors.
CFP

Cable Modem Termination System
The hub of a cable provider plant where all the connections from subscribers converge into.
CMTS

Cloud
The software and services that run on Internet services instead of locally on your computer.

Coherent Optical Transmission
Transmission of the optical signals that uses all properties of the signal (intensity, frequency, phase, polarization) to pack more data into that signal. In contrast direct detect transmission uses only the intensity.

Commercial off the Shelf Equipment
Equipment that is not custom made, but that can be bought immediately from a seller's stock.
COTS

Commercial Temperature Specification
Temperature specification that is roughly between -5 and 80 degrees Celsius. This is the minimum standard required for telecom equipment.
C-TEMPO

Core Network
The section of a telecom network that connects service providers to each other and to the Internet cloud.

Course Wavelength Division Multiplexing
A WDM standard in which the system transport typically eight wavelengths with a channel spacing of 20nm, usually from 1470nm to 1610nm.
CWDM

Dark Fiber
Optical fiber that has already been laid out but is not being used for transmission. This dark fiber provides potential for future network scale up or can be leased to other carriers.

Datacenter Interconnects
Links used to connect one datacenter with another. They are usually on the range of a few kms or tens of kms
DCI

Datacom
Data communication: the industry that focuses on installating and maintaining links between datacenters or inside a data center.

Demarcation Technology
Technologies that provide the interface between the provider's access network and the end customer's on-premises wiring / network.
DEMARC

Dense Wavelength Division Multiplexing
A WDM standard that has much narrower channel space than DWDM, with 0.4 or 0.8 channel spacing. It is used for links in which carriers want to maximize their fiber capacity or very dense access networks.
DWDM

Digital Signal
A signal that varies discontinuously and is just sampling (not a full representation) of a physical quantity.

Digital Signal Processor
The component of a communication systems that codes or decodes digital data from a signal. It's necessary for coherent communications.
DSP

Discrete Photonics
A photonic approach in which the components are manufactured separately and then interconnected via optical fiber. This is contrast to integrating the photonic components on a single chip.

Distributed Access Architecture
Architectures that decentralize the access network of a provider, splitting the headend into several nodes.

Docsis
The standard that regulates cable provider links to subscribers.

Downstream
The telecommunications link that goes from the carrier to the end user. It is the channel that users download data with.

Edge of the Network
The part of a specific network that is closer to the end user.

Erbium Doped Fiber Amplifier
An optical fiber with embbeded Erbium bits that uses electrical current to increase the intensity of an optical signal. These amplifiers allow the optical signal to travel for a longer distance.
EDFA

Fabless Model
A model in which a company designs semiconductor chips but outsources the chip manufacturing to a specialized factory (foundry). EFFECT Photonics is a fabless company.

Fiber to the Home
An upgrade to fixed access networks (such as cable) in which Internet service to the subscriber home is delivered via optical fiber. This is in contrast to legacy networks that deliver service via electrical copper or coaxial wires.
FTTH

Forward Error Correction
Error correction codes that allow a receiver to detect data errors without requiring the transmitter to resend data. This saves time and channel capacity.

Foundry
A semiconductor chip fabrication plant (also called a fab).

Free Space Optics
Optical communication technology that transmits and receives light wireless through air. This is in contrast to using a solid medium like optical fiber.

Fronthaul
Links in a mobile network that connect remote radio units to a centralized controller. They are the intermediate links that connect wireless end users to the core transport network.

Full Band Tunable
A transceiver that can tune its frequency across the entire optical C-band (infrared wavelengths from 1535-1565 nm)

Gigahertz
A frequency unit equivalent to one billion Hertz. Many microwave signals are in this frequency range.
GHz

Grey Transceiver
A standard optical transceiver that cannot tune its frequency channel. It's called grey because unlike tunable transceivers, it cannot change its "color".

Headend
A control center (often in a cable network) where signals from subscribers and nodes are brought together and managed before introducing them to the rest of the cable network.

Host Agnostic
A device (such as a pluggable transceiver) that can work with any kind of host device. Achieving this requires interoperability standards.

Hybrid Fiber Coaxial Network
A fixed access network (such as cable networks) that uses fiber until a certain point but then uses coaxial cable to reach the subscriber.
HFC NETWORK

Hyperscale Data Center
A data center that is much larger than a typical enterprise data center. A common definition is that it needs to have more than 5000 servers. They are more power efficient because energy and cooling can be centralized in a single location.

Hyperscaler
A company that builds hyperscale data centers. All the big tech giants (Microsoft, Google, Amazon, Facebook) do this.

Indium Phosphide
A III-V semiconductor material that is commonly used for high-frequency electronics and photonics circuits. It is the most common material platform used to build semiconductor lasers for communications, and the material of choice for EFFECT Photonics circuits.
InP

Information and Communication Technology
An umbrella term that refers to all the infrastructure and components that enable modern computing and communications.
ICT

Integrated Photonics
Integrating optical components on a semiconductor chip, similar to how electronics integrates electrical components.

Intra Data Center Interconnect
Connections between servers and buildings of the same data center. They can range from a hundreds of meters in distance to a few kilometers.

LAN PHY
This usually refers to an Ethernet network interface, usually 10G.

Latency
A metric in communication networks that measures how fast data can travel from one end to the other and back. Low latency is vital to many modern communications use cases, such as gaming or video conferencing.

Long-Haul Network
Networks links longer than 1000kms

Medium Access Control Layer
The layer of a network that controls the hardware responsible for transmission medium (air, Ethernet cable, coaxial, fiber).
MAC

Metro Networks
A network that providers connectivity within a metropolitan region. Its links are longer than those of an access network but shorter than long-haul links.

Midhaul
The links of a 5G radio access network that connect the distribution unit to the central unit (CU).

Modulator
A device that imposes a lower-frequency signal (the information) into a higher-frequency signal (the carrier signal) for the purposes of transmission.

Moore's Law
The empirical observation made by Gordon Moore in 1965 that the number of transistors in an electronic integrated circuit doubles roughly every two years. It is a guiding principle and target for the electronics semiconductor industry.

Multiplexer
A device that selects between several input signals and forwards the selected input into a single output line.

Nanometer
A billionth of a meter. It is a common unit for semiconductor fabrication processes.

Narrow Tunable
Said of a tunable DWDM transceiver that can only scan through a small section of the C-band.

Network Function Virtualisation
Using It virtualization technologies to emulate network functions that previously required specialized hardware. It allows network operators to replace this expensive hardware with affordable commercial off-the-shelf servers
NFV

Node
A redistribution point or endpoint within a network. It usually contains a device attached to the network that is capable of transmitting and receiving of the communications channel.

Node Split
The process of splitting a node (and all its associated links) into two or more nodes. By reducing the number of links and customers served by a single node, the network operator can provide more capacity to customers.

Open Optical Networking
The network paradigm in which telecom operators are not "locked-in" to a specific vendor and can instead build their networks with parts from different vendors. Achieving this requires the use of common standards and open software interfaces that can work with equipment of different vendors.

Optical Amplifier
An optical device that amplifies an optical signal with the help of an electrical pumping current.

Optical Engine
The part of an optical transceiver that handles the generation, modulation, and detecting of light.

Optical Fiber
A flexible, transparent fiber made by drawing pure glass (silica) or plastic into a diameter slightly thicker than a human hair.

Optical Losses
The inherent weakening of an optical signal as it passes through a transmission medium like air or fiber. It varies depending on the material used.

Optical Modulator
A device that imposes a lower-frequency signal (the information) into an optical carrier signal for the purposes of transmission through optical fiber.

Optical Network
The layer of a network that is composed of optical components.

Optical System-On-Chip
Integrating every optical function (including laser, amplifier modulator, detector) on a single chip. This can increase the efficiency of the optical engine and make it easier to mass produce.

Optical Transceiver
An optical communications device that sends an receives signal via optical fiber.

Packaging
In the case of transceiver development, it is the process of assembling the different parts of the transceiver (electronics, PIC, power supply) into the same package.

Partial Integration
In contrast to full integration / system-on-chip, an approach where only a few optical components are integrated on the same chip, while others are discrete and separate (such as the laser)

Passive Component
An optical component that does not require additional electrical energy to operate. Couplers, splitters, waveguides are an example of this.

Photon
The smallest unit of a beam of light. It does not have mass and travels at the speed of light.

Photonic Integrated Circuit
An optical circuit in which the components are integrated on a chip.
PIC

Photonics
The technological field that aims to integrate optical components on a single semiconductor chip, in a similar way to how electronics integrates electrical components on a chip.

Physical Layer
The lowest layer in the OSI model of networks. It is the layer closest to the physical connection between devices and that interfaces with the transmission medium
PHY

Pluggable
A smaller transceiver that can be easily "plugged" into another device such as a switch or router.

Power Usage Effectiveness
A ratio that describes how efficiently a data center uses energy. It is the ratio of total energy used by a data center facility to the energy delivered to computing equipment. An ideal PUE is 1.0 (energy deliver is perfectly efficient).
PUE

Pure Play Foundry
A semiconductor chip factory that manufactures devices for other companies without designing them. Two big examples are GlobalFoundries and TSMC in Taiwan.

Quad Small Form Factor Pluggable
The "big brother" of the SFP module format, with four lanes that allow for speeds four times higher than the corresponding SFP.
QSFP

Quantum Computer
A device that uses the properties of quantum mechanics (superposition, interference, entanglement) to perform calculations. In theory, these computers can solve certain computational problems (such as the factorization behind encryption) much faster than classical computers.

Quantum Key Distribution
A secure communication method that implements properties of quantum mechanics. These properties allow two communicating users to easily detect the presence of an eavesdropper.

Quantum Safe Encryption
Also called post-quantum or quantum-resistant encryption. Encryption algorithms that are thought to be secure against an attack by quantum computer.

Qubit
The quantum version of a classical information bit. While a normal bit can be just 0 or 1, a qubit can have a combination of 0 or 1 states.

Reconfigurable Optical Add Drop Multiplexer
A multiplexer that can add or drop optical signals using WDM technology, without having to change them into electrical signals. Its development was a vital breakthrough that made WDM technology more widespread.
ROADM

Remote PHY
A type of distributed architecture in cable access networks in which the physical layer (PHY) is moved from the cable headend to the nodes in the edge of the network. It reduces the load on the headend, allowing to handle more fiber connections.

Self Tuning
An algorithm that allows a WDM optical transceiver to tune itself without the manual input of a technician. It makes the process of network installation and management much easier.

Semiconductor Optical Amplifier
An optical amplifier built on a semiconductor chip and that can be integrated with other optical components on the same chip. Must be produced on an active material such as InP (so they can't be made in silicon)
SOA

SFP+
The evolution of the SFP transceiver module that can support 10Gbps channels (compared to the original SFP which supports 1G)

SFP28
The SFP transceiver module version that can support speeds of 25Gbps.

Signal to Noise Ratio
A key metric of communication systems that compares the level of a desired signal to the level of background noise.

Small Form-Factor Pluggable
A compact pluggable transceiver module that can be connected to networking hardware (switches, routers)
SFP

Software Defined Network
The networking paradigm that decouples the control layer from networking hardware and centralizes it in a hub (usually in the cloud). This means that the central office can manage all the hardware or virtualize network functions in servers. This makes network management much easier.
SDN

Spectral Bands
The different "colors" of the electromagnetic spectrum. The most common band for optical communications is the C-band (1530-1565nm) but there also other bands such as the L-band (1565-1625), the S-band (1460-1530nm) and the O-band (1260-1360nm).

Speed of Light
The speed of light in a vacuum (represented by c) is a fundamental physical constant and the "speed limit" of the universe. However, if light travels in a medium (such as air or fiber), the speed of light will decrease.

System Integrators
Companies that buy telecommunications equipment and use it to build and manage telecom infrastructure and systems. They provide the full system and management solution for network carriers.

Tail End Module
The module opposite to the central head-end. It's usually the remote module that is closer to the end customer.

Telecom
The industry that transmits information (through wire, radio, optical or other mediums) over longer distance. A related, but different industry datacom, which is focused on datacenters.

Terahertz
A frequency unit equal to a trillion Hertz (10^12). It is the frequency unit commonly used for optical signals.
THz

Time Division Multiplexing
A method of transmitting several independent signals over the same medium (such as fiber). Unlike WDM, TDM uses the same wavelength channel and the signals must split that channel and transmit in specific, alternating time slots.

Transceiver
A smaller device that can receive and transmit telecommunications signals. It's usually a smaller version of a transponder.

Transmission Rates
The rate at which information is transmitted over a communications link.

Transponder
A device that can receive and transmit telecommunications signals. It's usually a larger device that needs its own space in a shelf.

Transport Network
The part of the telecommunications network that relays data from one node of the telecom carrier network to another. This in contrast to the access network, which takes the data to the end customer.

Truck Roll
A maintenance / repair visit to a site. Network operators want to minimize truck rolls to minimize their operational expenditure.

Upstream
The telecommunications link that goes from the end user back to the carrier. This is important in situations when the end user uploads data.

Vertical Integration
A company that extends the operations in its supply chain, bringing in previously outsourced operations in-house.

Wafer
A round piece of semiconductor material, such as silicon or InP. The larger the wafer sizes, the more devices can be produced (at a lower price). The consumer electronics industry uses 12 inch wafers to produce at a very high volume, but the lower volume telecom industry uses 3-6 inch wafers to produce its devices

Wavelength Locker
A device that stabilizes and locks the emission of a lasers into a single wavelength. Without the locker, the laser's wavelength might drift with temperature and other mechanical instabilities.

Wavelength Selective Switch
Components in WDM networks that will route (switch) signals between optical fibers depending on the required wavelengths.