Third-generation (3G) systems provide access to a wide range of telecommunication services supported by both fixed telecommunication networks and other services specific to mobile users. A range of mobile terminal types will be supported and may be designed for mobile or fixed use. Key features of 3G systems are the compatibility of services, small terminals with worldwide roaming capabilities, Internet access and other multimedia applications, high bandwidth, and a wide range of services and terminals.

Fourth-generation (4G) networks extend 3G network capacity by an order of magnitude, rely entirely on a packet infrastructure, use network elements that are 100 percent digital, and offer extremely high bandwidth.

A contraction of the words abnormal end, used to describe a computer crash in the mainframe world.

A form of optical attenuation in which optical energy is converted into an alternative form, often heat. Often caused by impurities in the fiber, hydroxyl absorption is the best known form.

The critical angle within which incident light is totally internally reflected inside the core of an optical fiber.

The set of technologies used to reach the network by a user.

A device used in SONET and SDH systems that has the capability to add and remove signal components without having to demultiplex the entire transmitted transmission stream, a significant advantage over legacy multiplexing systems such as DS3.

Transmission equipment (including media, amplifiers, splice...