Glossary

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.

The net number of bits of information that are actually delivered to the user, without including any additional bits that might be used for control or protocol overhead.

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

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

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

A device that takes a single input signal and selects one of many data-output-lines, which is connected to the single input.

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.

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

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

An electronic component that decodes a digital signal of 0s and 1s and transforms it into a continuous analog signal, such as those of audio or laser light.

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.

The degradation of a light signal when travelling through an optical fiber. The same phenomenon happens when a prism splits white light into several colors.

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

Lasers that incorporate a Bragg reflector in their structure to provide wavelength-selective feedback. The reflector consists of alternating layers with varying refractive indices, stabilizing the laser's output wavelength.

Lasers that use a periodic structure within the gain medium to provide feedback and stabilize the laser’s output wavelength.

The standard that regulates cable provider links to subscribers.

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

The transmission of data in two directions simultaneously.