gain - The increase in output current, voltage, or power relative to input current, voltage, or power, respectively. Gain is usually expressed in dB.

Gantt chart - A simple chart that diagrams a project schedule.

gap distance - The distance between optical fiber ends.

gas tube protector - An overvoltage protector featuring metallic electrodes that discharge in a gas atmosphere within a glass or ceramic envelope. This type of protector does not require replacement each time it discharges.

gateway - An internetworking service used to connect dissimilar applications running on different networks with different communications protocols. Gateways normally operate at one or more of the top four layers of the Open Systems Interconnection Reference Model. See also portal and wireless LAN gateway.

Gaussian noise - In electrical conductors, the noise resulting from molecular vibration. This background noise increases logarithmically with temperature.

general conditions - Any of a number of standards or code documents published that are applicable to the project delivery method.

Gigabit Ethernet (GbE) - A LAN protocol with a data transfer rate of 1000 Mbls (1 Gb/s).

gigabit per second (Gbls) - A transmission rate denoting one billion bits per second.

gigahertz (GHz) - A unit of frequency denoting one billion cycles per second. See also hertz (Hz).

glass fiber - See optical fiber.

global unlock - An input that, when activated, generates a signal that unlocks doors in the access control systems.

gopher pole - A telescoping pole for placing or pulling cable above suspended ceilings or limited access areas.

Grade 1 residential telecommunications cabling - Cabling that provides a generic cabling system that meets the minimum requirements for telecommunications services (e.g., telephone, satellite, community antenna television, data services).

Grade 2 residential telecommunications cabling - Cabling that provides a generic cabling system that meets the requirements for current needs as well as for developing basic, advanced, and multimedia telecommunications services.

grade of service (GoS) - With respect to the percentage of blocked calls to the completed calls, defined as calls blocked. (Nortel)

graded index profile - The refractive index profile of an optical fiber. See gradedindex fiber.

graded-index fiber - An optical fiber design in which the refractive index decreases continuously from the center of the core to the outside of the core.

grommet - Generally a rubber insulator used to protect a wire passing through an aperture. See also bushing.

ground - A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth, or to some conducting body that serves in place of earth. (TIA) See also approved ground and earth ground.

grounded - Connected to earth or to some conducting body that serves in place of the earth.

grounded conductor - A system or circuit conductor that is intentionally grounded.

ground enhancement material - Any material used to enhance the soil for a low resistance to ground.

ground fault circuit interrupter (GFCI) - A device intended for the protection of personnel that functions to deenergize a circuit or portion thereof, within an established period of time, when a current to ground exceeds the values established for a Class A device. (NEC)

ground fault - An undesirable connection to ground.

ground grid - An extensive system of bare conductors, buried below the surface of the earth, intended to provide a low-resistance connection to earth and to equalize the potential within the area covered. (TIA)

grounding - See grounded.

grounding bushing - A fitting for attaching a ground wire to a conduit.

grounding conductor - A conductor used to connect the grounding electrode to the building's main grounding busbar. (TIA)

grounding electrode - 1. A conductor, usually a rod, pipe, or plate (or group of conductors), in direct contact with the earth for the purpose of providing a lowimpedance connection to the earth. (TIA) 2. A device that establishes an electrical connection to the earth. (NEC)

grounding electrode conductor (GEC) - The conductor used to connect the grounding electrode to either the equipment grounding conductor, or to the grounded conductor of the circuit at the service equipment, or at the source of a separately derived system. (TIA)

grounding electrode system - One or more grounding electrodes bonded to form a single reliable ground for a structure. See Codes, Standards, and Regulations.

grounding equalizer (GE) - A conductor that interconnects elements of the telecommunications grounding infrastructure (formerly telecommunications bonding backbone interconnecting bonding conductor.

grounding grid - See grounding mat

grounding mat - An extensive system of bare conductors, buried below the surface of the earth, intended to provide a low-resistance connection to earth and to equalize the potential within the area covered. (TIA)

grounding system - A system of hardware and wiring that provides an electrical path from a specified location to an earth ground point.

grounding terminal - A suitable bar, bus, terminal strip, or binding post terminal where grounding and bonding conductors can be connected.

ground loop - Interference in electrical communication links due to the ground at each end being at different potentials.

ground plane - A system of conductors placed beneath an elevated antenna as a near field reflective point serving as an earth ground.

ground potential - The zero reference level used to apply and measure voltages in a system.

ground potential rise (GPR) - A voltage difference between a grounding electrode system and the earth return currents produced by a lightning strike or a powerfault current.

ground-reflected wave - The portion of a wave that reaches a receiving antenna after it has reflected off the Earth's surface.

ground resistivity - The measured direct current resistance of a volume of earth.

ground ring - A ground ring encircling the building or structure, in direct contact with the earth at a depth below earth surface not less than 0.76 m (2.5 ft), consisting of at least 6 m (20 ft) of bare conductor not smaller than No. 2. (NEC)

ground rod array - Consists of two or more ground rod assemblies, bonded together, separated by a distance equal or greater than the length of the ground rod assembly.

ground wave - A low-frequency radio wave that bends along the earth's surface rather than traveling through the atmosphere.

ground wire - See bonding conductor and bonding conductor for telecommunications.

groupware - A network software application designed to enhance administrative communications (e.g., e-mail, scheduling, coordination, collaboration) among users in an organization.

guaranteed maximum price (GMP) - Bidders may be required to state a GMP that is not to be exceeded. This allows the owner an understanding of the absolute maximum cost of the project before start of construction.

guard band - In analog signals, guard bands are small bands of unused frequencies that are allocated as buffers between data carrying channels: Guard bands provide a buffer against interference from adjacent channels due to signal drift.

guy - A steel stranded wire used to provide counter tension to the pole opposite that of the installed cable pull tension to keep the pole upright.

guy rod end - A single, double, or triple eye at the end of a guy rod for the attachment of the guy wire to the connect point above the ground anchor.