This document has been composed to provide an authoritative reference on antenna terminology used in Powertec documentation. The definitions have been compiled with reference to IEEE and ETSI documents, along with documentation from non-governing but respected industry leaders, which are listed below for additional reference.

2GSecond generation of mobile wireless communication technology, which uses the digital technologies for the mobile communication.
3GThird generation of wireless communication technologies, which support broadband voice, data and multi-media communications over wireless networks.
3.5GGenerally refers to the technologies beyond the well defined 3G wireless/mobile technologies. Currently, HSDPA is considered the primary 3.5G technology.
3GPPCollaboration agreement between ETSI (Europe), ARIB/TTC (Japan), CCSA (China), ATIS (North America) and TTA (South Korea).
4GFourth generation of wireless communication technologies. Informally used to refer to LTE/E-UTRA.
802.11A group of wireless specifications developed by the IEEE for wireless local area network (WLAN) communications. It details a wireless interface between devices to manage packet traffic to avoid collisions. Some common specifications include the following: 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac.
802.11aAn extension to IEEE 802.11 that applies to wireless LANs and provides up to 54 Mbps in the 5 GHz band. 
802.11gAn extension to IEEE 802.11 which offers wireless transmission up to 54 Mbps in the 2.4 GHz band.
802.11nIEEE Standard for WLAN enhancements for higher throughput designed to raise effective WLAN throughput to more than 300 Mbps.
802.11xRefers to a group of evolving WLAN standards that are elements of the IEEE 802.11 family of specifications. 802.11x should not be mistaken for any one of its elements because there is no single 802.11x standard.
802.15A group of IEEE standards that specifies communications for wireless personal area networks (WPAN) based on the Bluetooth tehnologies.
802.16A group of IEEE standards that defines wireless communications between a subscriber site and a core network. It is called Wireless MAN technology, which is also branded as WiMAX.
Absolute Radio Frequency Channel Number (ARFCN)Channel numbering scheme used to identify specific RF channels in a radio system. UARFCN for UMTS systems, EUARFCN for E-UTRA systems.
Absorption SpectrumA diagram which shows the wavelengths of electromagnetic radiation absorbed by a material. The material could be a gas, a solute or a solid.
Access Point (AP)A device controlling a single wireless subnetwork. Typically referring to a device acting as a central transmitter and receiver of WLAN radio signals.
Active AntennaAntenna, where the electromagnetic signal can be amplified or processed electronically before radiation or after reception or both
Adaptive Antenna System (AAS)An antenna system having circuit elements associated with its radiating elements such that one or more of the antenna properties are controlled by the received signal
Adaptive Modulation and Coding (AMC)Protocol that sets modulation and coding parameters depending on channel state. Modulation and code rate changes in complexity to maintain the received signal quality or channel conditions.
Adaptive Power Control (APC)Automatic function implemented to offer a dynamic power control that delivers maximum power only during deep fading; in this way for most of the time the interference is reduced. 
Adjacent Channel Interference Ratio (ACIR)Ratio of wanted power to the interference power from the adjacent channels.
Adjacent Channel Leakage Ratio (ACLR)Ratio of the transmitted power to the power measured after a receiver filter in the adjacent RF channel. Measure of transmitter performance in WCDMA systems.
Adjacent Channel Selectivity (ACS)Measurement of a receiver's ability to process a desired signal while rejecting a strong signal in an adjacent frequency channel.
Air InterfaceConductor-free medium, usually air, between a transmitter and the receiver through which communication is achieved by means of a modulated inductive or propagated electromagnetic field.
AliasingSignal distortion that occurs when sampling frequency of a signal is less than the Nyquist rate.
ALOHAPacket-based radio access protocol where every packet sent is acknowledged. Lack of an acknowledgement is an indication of a collision and results in a retransmission.
AmplifierElectronic device for increasing the amplitude of broadcast signals.
Ancillary EquipmentElectrical or electronic equipment, that is intended to be used with of a receiver or transmitter.
AntennaDevice that serves as a transducer between a guided wave (e.g. coaxial cable) and a free space wave, or vice versa. Alternate definition: Device designed to radiate or receive electromagnetic waves.
Antenna EfficiencyRatio of antenna gain to antenna directivity. It corresponds to the level of electrical losses in the antenna, a highly efficient antenna would provide maximal gain with maximal beamwidth.
Antenna Factor
The factor that allows to known, from the voltage registered at the terminals, either the value of the electric field or the value of the magnetic field by the following ratios: Afe = E / Us in m-1 for the electric field. Afh = H / Us in m-1 for the magnetic field.
Antenna GainThe ratio of the radiation intensity, in a given direction, to the radiation intensity that would be obtained if the power accepted by the antenna were radiated isotropically.
Array AntennaAn antenna comprised of a number of identical radiating elements in a regular arrangement and excited to obtain a prescribed radiation pattern.
Artificial AntennaNon-radiating dummy load equal to the nominal impedance specified by the applicant.
AttenuationDecreasing in signal magnitude between two points. These points may be along a radio path, transmission line or other devices.
AttenuatorDevice specifically designed to decrease the magnitude of a signal transmitted through it.
Automatic Gain Control (AGC)System which holds gain and, accordingly, the output of a receiver substantially constant in spite of input-signal amplitude fluctuations.
Automatic Power Control (APC)Technique of measuring the performance of a radio channel and adjusting the power of the transmitter to a level appropriate for link characteristics.
Automatic Repeat reQuest (ARQ)Communication protocol in which the receiving device detects errors and requests retransmissions.
Automatic Transmit Power Control (ATPC)Function implemented to offer a dynamic power control that delivers maximum power only during deep fading; in this way for most of the time the interference is reduced and the transmitter operates in a higher linearity mode.
Average Radiation IntensityThe average radiation intensity is equal to the total power radiated by the antenna divided by 4π.
Axial RatioRatio of maximum to minimum power contained in the field components of the polarization ellipse.
Backfire AntennaAn antenna consisting of a radiating feed, a reflector element, and a reflecting surface such that the antenna functions as an open resonator, with radiation from the open end of the resonator.
Back LobeA radiation lobe whose axis makes an angle of approximately 180 degrees with respect to the beam axis of an antenna. [See: Rear Lobe]
BackhaulConnection from base stations to the core network.
BackscatterRadio wave propagation in which the direction of the incident waves, resolved along a reference direction are oppositely directed.
BalunTransformer, used to convert balanced into unbalanced signals or vice-versa.
Bandwidth (Antenna)The range of frequencies within which the performance of the antenna, with respect to some characteristic, conforms to a specified standard.
Bandwidth (Radio)Bandwidth is the portion of the frequency spectrum required to transmit desired information. Each radio channel has a center frequency and additional frequencies above and below this carrier frequency which is used to carry the transmitted information.
Base Transceiver Station (BTS)A network component which serves one cell, and is controlled by a Base Station Controller. The BTS can consist of one or more TRXs with or without common control equipment.
Base Station (BS)A physical grouping of equipment which provides access to a core network by receiving and transmitting radio signals from and to Mobile Stations within its area of coverage.
BasebandTransmission means through which digital signals are sent without frequency shifting. In general, only one communication channel is available at any given time. Non-modulated transmission.
Beam (Antenna)The major lobe of the radiation pattern of an antenna.
Beam FormingFunctionality of an antenna system, where the amplitude and phase of radiating aperture of the antenna system is optimized through different techniques to achieve a desired shaped radiation pattern.
Beam Forming GainAdditional (antenna) gain realized by using beam forming techniques in smart antenna systems.
Beam SteeringFunctionality of an antenna system, which allows the change in the direction of the main lobe of its radiation pattern.
BeamwidthAntenna beamwidth, also known as the half-power beamwidth, is the angle between the two directions at which the measured copolar pattern is 3 dB below the value on the main beam axis. See also: Half Power Beamwidth, HPBW.
Binary Phase Shift Keying (BPSK)Type of phase modulation using two distinct carrier phases to signal ones and zeros.
Bit Error Rate (BER)Percentage of bits that have errors relative to the total number of bits received in a transmission, usually expressed as ten to a negative power
Blade AntennaA form of monopole antenna that is blade-shaped for strength and low aerodynamic drag.
BlockA unit of information consisting of a header and an information field. A block is a set of consecutive bits equivalent to one frame; each bit belongs to one and only one block.
Block Error Rate (BLER)Error rate of the transport (data) blocks passed by the physical layer to MAC layer for a given transport channel (i.e. physical layer error rate).
BoresightDirection of maximum radiation of a directional antenna. Alternate definition: optical axis of a directional antenna, along which the peak antenna gain is found.
Carrier (Company)Licensed telecommunication company who provides telecommunication services and services for call or message routing purposes.
Carrier (Transmission)Modulated waveform conveying physical channels. Alternate: Continuous frequency capable of being modulated or impressed with a second signal.
Carrier Aggregation (CA)Aggregation of two or more component carriers in order to support wider transmission bandwidths. Inter-band CA refers to aggregation of carriers in different operating bands, as opposed to intra-band CA which refers to aggregation of carriers within the same operating band.
Carrier FrequencyCarrier Frequency refers to the nominal frequency of a carrier wave, the frequency of the unmodulated electrical wave at the output of an amplitude modulated, the center frequency of a frequency modulation signal, frequency modulated, or phase modulated transmitter of the output of a transmitter when the modulation is zero. Also known as RF Carrier
Carrier-to-Noise Ratio (C/N or CNR)Ratio of signal power to noise power in the defined measurement bandwidth: For digital modulation: CNR = Es/N0, the energy-per-symbol to noise-density ratio; the signal power is measured in the occupied bandwidth, and the noise power is normalized to the modulation-rate bandwidth.
Carrier PairTwo different carriers which are allocated together to provide one uplink and one downlink. Normally the two carriers are allocated at a fixed frequency spacing (the duplex separation).
Carrier PowerAverage power supplied to the antenna transmission line by a transmitter during one cycle taken under the condition of no modulation.
Central Station (CS)Base station which communicates each way with many terminal stations and, in many cases, repeater stations.
ChipA unit of modulation used in direct sequence spread spectrum modulation.
ChirpSignal in which the carrier frequency increases or decreases with time.
Circular PolarisationPolarisation of an electromagnetic wave in which either the electric or the magnetic vector executes a circle perpendicular to the path of propagation with a frequency equal to that of the wave.
Coaxial AntennaAn antenna comprised of an extension to the inner conductor of a coaxial line and a radiating sleeve that in effect is formed by folding back the outer conductor of the coaxial line.
Co-Channel Interference (CCI)Capability of a receiver to demodulate the desired signal and achieve the minimum specified BER performance in the presence of an unwanted signal at the same assigned channel/frequency.
Code Division Multiple Access (CDMA)Technique for spread-spectrum multiple-access digital communications that creates channels through the use of unique code sequences.
Collinear Array AntennaA linear array of radiating elements, usually dipoles, with their axes lying in a straight line. Typically shortened to "Collinear Antenna".
Co-polarisationThat polarization that the antenna is intended to radiate/receive. Alternate Spelling: Co-polarization.
Co-polar PatternDiagram representing the radiation pattern of a test antenna when the reference antenna is similarly polarized, scaled in dBi or dB relative to the measured antenna gain.
Co-polarUsed to define parameters (such as gain or radiation pattern) applicable to radiated signals in the wanted plane of polarization (for linear polarization) or wanted direction of rotation (for circular polarization).
CongestionState of a system or a part thereof which is entered when the traffic load exceeds the capacity of the system which is then no longer able to meet the negotiated QoS objectives for the already established connections and/or for the new connection requests.
Contention (Access)A conflict between the demands made on a network termination in multipoint access.
Contention RatioContention Ratio (or over subscription ratio) is the number of subscribers sharing the same data capacity. The lower the contention ratio the higher the quality of service. A 50:1 contention ratio means that up to 50 subscribers are sharing the same bandwidth at any one time.
Contention-Based ProtocolProtocol that allows multiple devices to share the same spectrum by defining the events that occurs when two or more transmitters attempt to simultaneously access the same channel and establishing rules by which a transmitter provides reasonable opportunities for other transmitters to operate on the same channel.
Corner ReflectorA reflecting object consisting of two or three mutually intersecting conducting flat surfaces.
Cross PolarisationIn a specified plane containing the reference polarization ellipse, the polarization orthogonal to a specified reference polarization.
Cross Polarisation Discrimination (XPD)Cross polarization discrimination of an antenna, in a given direction, at a transmit or receive frequency, is defined as the ratio of the on-axis co-polar gain to the cross-polar gain in that direction. It is expressed in dB, and often abbreviated to XPD.
Cross PolarUsed to define parameters (such as gain or radiation pattern) applicable to radiated signals orthogonally to the co-polar plane of polarization.
Cross Polar IsolationThe ratio of the power coupled between the two orthogonally polarised ports of a dual polarised antenna.
Cross Polar PatternDiagram representing the radiation pattern of a test antenna when the reference antenna is orthogonally polarized, scaled in dBi, or dB relative to the measured antenna gain.
DepolarisationThe conversion of power from a reference polarization into the cross polarization.
Complex Dielectric ConstantThe complex permittivity of a physical medium in ratio to the permittivity of free space.
Dipole AntennaAny one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole. Common usage considers the dipole antenna to be a metal radiating structure that supports a line current distribution similar to that of a thin straight wire so energized that the current has a node only at each end.
Directional AntennaAn antenna having the property of radiating or receiving electromagnetic waves more effectively in some directions than others. This term is usually applied to an antenna whose maximum directivity is significantly greater than that of a half-wave dipole
DirectivityThe ratio of the maximum radiation intensity in a given direction from the antenna to the radiation intensity averaged over all directions.
Director ElementA parasitic element located forward of the driven element of an antenna, intended to increase the directivity of the antenna in the forward direction.
Discone AntennaA biconical antenna with one cone having a vertex angle of 180°, i.e. in which one of the cones is replaced by a disc.
Donor AntennaAntenna, typically rooftop mounted, supplying RF input to a repeater/rebroadcast system. 
Downlink Dual CarrierDownlink Dual Carrier is a feature allowing resources to be assigned to a mobile station on up to two radio frequency channels within the same frequency band.
Driven ElementA radiating element coupled directly to the feed line of an antenna.
Eb/N0Bit Energy to Noise ratio.
Effective Isotropically Radiated Power (EIRP)In a given direction, the gain of a transmitting antenna multiplied by the net power accepted by the antenna from the connected transmitter. Also known as Equivalent Isotropically Radiated Power. The EIRP allows making comparisons between different emitters regardless of type, size or form. From the EIRP, and with knowledge of a real antenna's gain, it is possible to calculate real power and field strength values.
Effective Radiated Power (ERP)In a given direction, the relative gain of a transmitting antenna with respect to the maximum directivity of a half-wave dipole multiplied by the net power accepted by the antenna from the connected transmitter. Also known as Equivalent Radiated Power.
E-PlaneFor a linearly polarized antenna, the plane containing the electric field vector and the direction of maximum radiation.
Electric Field StrengthA vector that corresponds to strength exercised independently on a loaded particle of a displacement in the space. It is expressed in volts per metre (V/m)
Electrical TiltAngular shift in elevation of the direction of maximum gain of the antenna by a specific electrical design of the antenna.
Electromagnetic Interference (EMI)Any source of RF transmission that is within the frequency band used by a communication link, which degrades the performance of this link.
Electromagnetic SpectrumElectromagnetic Spectrum refers to the full range of electromagnetic frequencies, which include Radio Frequency (RF).
European Telecommunications Standard Institute (ETSI)Based in France, ETSI is officially responsible for standardization of Information and Communication Technologies (ICT) within Europe.
Evolved Packet Core (EPC)A framework for an evolution or migration of the 3GPP system to a higher-data-rate, lower-latency, packet-optimized system that supports, multiple RATs.
Evolved Packet System (EPS)An evolution of the 3G UMTS characterized by higher-data-rate, lower-latency, packet-optimized system that supports multiple RATs. The Evolved Packet System comprises the Evolved Packet Core together with the evolved radio access network (E-UTRA and E-UTRAN).
Evolved-UMTS Terrestrial Radio Access (E-UTRA)Also known as UMTS Long Term Evolution (LTE). Key 3G technology to ensure the competitiveness of UMTS and provide a high-data-rate, low-latency and packet-optimized system.
FadingFading is the variation in signal strength from its normal value. Fading is normally negative and can be either fast or slow. It is normally characterized by the distribution of fades, Gaussian, Rician, or Rayleigh.
Far-Field PatternAny radiation pattern obtained in the far-field of an antenna.
Far-Field RegionThat region of the field of an antenna where the angular field distribution is essentially independent of the distance from a specified point in the antenna region.
Fast FadingFast fading is the short term component associated with multipath propagation. It is influenced by the speed of the mobile terminal and the transmission bandwidth of the signal.
Fast HandoffFast Handoff is a way that access points can let authenticated users roam among different access points without losing authentication.
Federal Communications Commission (FCC)Federal Communications Commission (FCC) is the regulatory body governing communications technologies in the US. 
Feed (Antenna)For continuous aperture antennas, the feed is the primary radiator; for example, a horn feeding a reflector.
Feed LineA transmission line interconnecting an antenna and a transmitter or receiver or both.
Feed Horn (Feedhorn)A small horn antenna used to convey radio waves between the transmitter/receiver and the parabolic reflector.
Feeder CableA feeder is a transmission system which lies between the access network and the service node.
Flat FadingType of fading in a communications channel that attenuates or fades all frequencies in the channel in the same amount.
Folded DipoleAn antenna composed of two or more parallel, closely-spaced dipole antennas connected together at their ends with one of the dipole antennas fed at its center and the others short-circuited at their centers.
Footprint (Wireless Communications)Refers to geographical areas in which an entity is licensed to broadcast its signal.
Free-Space Path Loss (FSPL)The loss between two isotropic radiators in free space resulting from the decrease in power density with the square of the separation distance. Expressed as a power ratio.
FrequencyMeasurement of the number of times that a repeated event occurs per unit time. Expressed in cycles per second, i.e. Hertz.
Frequency BandA continuous set of frequencies lying between two specified limiting frequencies. Band of frequencies over which the performance characteristics of the equipment/antenna are set within specified limits.
Frequency DiversitySimultaneous use of multiple frequencies to transmit information. This is a technique used to overcome the effects of multipath fading since the wavelength for different frequencies result in different and uncorrelated fading characteristics.
Frequency Division Duplex (FDD)Duplex technique where the traffic in each direction of a two-way telecommunications link is carried on two different carrier frequencies, each dedicated to the traffic in one direction. 
Frequency Division Multiple Access (FDMA)Multiple access technology that allows multiple users to share the radio frequency spectrum by putting each traffic channel on a discrete frequency band.
Frequency ReuseTechnique of reusing frequencies and channels within a communications system to improve capacity and spectral efficiency.
Frequency Shift Keying (FSK)Modulation where the data causes the frequency of the carrier to change from one frequency to another on discrete stages.
Forward Error CorrectionMethod of introducing redundancy to binary data that allows for the detection and/or correction of errors introduced during transmission of that data. FEC enables the receiver to detect and fix errors to packets without the need for the transmitter to retransmit packets
Fresnel ContourThe locus of points on a surface for which the sum of the distances to a source point and an observation point is a constant, differing by a multiple of a half-wavelength from the minimum value of the sum of the distances.
Fresnel RegionThe region (or regions) adjacent to the region in which the field of an antenna is focused.
Fresnel ZoneFresnel Zone is an elliptical area on either side of the straight line of sight that must also be clear for a long-range wireless network to work.
Front-to-Back Ratio (F/B Ratio)The ratio of the maximum directivity of an antenna to its directivity in a specified rearward direction. 
Gain (Antenna)The ratio of the radiation intensity, in a given direction, to the radiation intensity that would be obtained if the power accepted by the antenna were radiated isotropically.
Gain (System)Ratio of the output amplitude of a signal to the input amplitude of a signal.
Global Navigation System (GLONASS)Russian satellite location technology similar to global positioning system.
Global Positioning System (GPS)Global Positioning System (GPS) is a "constellation" of 24 satellites that orbit the Earth at a height of 10,900 miles, making it possible for people using ground receivers to determine their geographic location within 10 to 100 meters.
Ground PlaneElement within an installation, which might represent a metal chassis, a collector plate, a mass mesh or a unit, comprising these elements. The ground plane is intended to reduce the shield surface loop and to improve the equipotentiality of the
H-PlaneFor a linearly polarized antenna, the plane containing the magnetic field vector and the direction of maximum radiation.
Half Power Beamwidth (HPBW)In a radiation pattern cut containing the direction of the maximum of a lobe, the angle between the two directions in which the radiation intensity is one-half the maximum value. Alternate Definition: Angle between the two directions at which the measured copolar pattern is 3 dB below the value on the main beam axis.
Half Power DipoleA wire antenna consisting of two straight collinear conductors of equal length, separated by a small feeding gap, with each conductor approximately a quarter-wavelength long.
HandoverProcess in which the User Equipment continuously receives services while it crosses radio access areas covered with distinct radio access mode and/or radio system.
Hard HandoverHard handover is a category of handover procedures where all the old radio links in the UE are abandoned before the new radio links are established.
Helical AntennaAn antenna whose configuration is that of a helix. The diameter, pitch, and number of turns in relation to the wavelength provide control of the polarization state and directivity of helical antennas.
Horizontal PolarisationA linearly polarised electromagnetic wave whose electric field vector is horizontally polarized.
Horn (Antenna)An antenna consisting of a waveguide section in which the cross sectional area increases towards an open end that is the aperture.
Hybrid Automatic Repeat reQuestScheme wherein information blocks are encoded for partial error correction at receiver and additional, uncorrected errors are retransmitted.
Intermediate Frequency (IF)A frequency to which a carrier frequency is shifted as an intermediate step in transmission or reception.
ImpedanceA measure of the complex resistive and reactive attributes of a component in an alternating current circuit
Impedance Mismatch FactorThe ratio of the power accepted by an antenna to the power incident at the antenna terminals from the transmitter.
Input ImpedanceThe impedance presented by an antenna at its terminals.
InterferenceEffect of unwanted energy due to one or a combination of emissions, radiation, or induction upon reception in a radiocommunication system, manifested by any performance degradation, misinterpretation, or loss of information which could be extracted in the absence of such unwanted energy.
Inter-Symbol Interference (ISI)Distortion of the received signal caused by temporal spreading and consequent overlap of adjacent modulation symbols. Alternate Definition: An interference effect where energy from prior symbols in a bit stream is present in later symbols
International Telecommunications Union (ITU)United Nations agency that deals with telecommunications issues.
Intermodulation ProductsUnwanted frequencies resulting from intermodulation between carriers or harmonics of emission or between any oscillations generated to produce the carrier.
Inter-Port IsolationRatio in dB of the power level applied to one port of a multi-port antenna to the power level received in any other port of the same antenna as a function of frequency.
Isolation (Between Antennas)A measure of power transfer from one antenna to another. The isolation between antennas is the ratio of power input to one antenna to the power received by the other, usually expressed in decibels.
Isotropic RadiatorHypothetical, loss less antenna having equal radiation intensity in all directions; used as a zero-dB gain reference in pattern measurements or directivity calculations.
Input Port(s)Flange(s) or connector(s) through which access to the antenna is provided.
Lens AntennaAn antenna consisting of an electromagnetic lens and a feed that illuminates it.
Lens (Electromagnetic)A three-dimensional structure, through which electromagnetic waves can pass, possessing an index of refraction that may be a function of position and a shape that is chosen so as to control the exiting aperture illumination.
Line of Sight (LoS)Describes an unobstructed radio path or link between the transmitting and receiving antennas of a communications system. Additional Terms: Near-Line of Sight, Non-Line of Sight, Radio-Line of Sight, Optical-Line of Sight.
Linear PolarisationA plane wave whose electric field vector is linearly polarized.
Link BudgetCalculation involving the gain and loss factors associated with the antennas, transmitters, transmission lines and propagation environment used to determine the maximum distance at which a transmitter and receiver can successfully operate.
Loading (Antenna)The modification of a basic antenna such as a dipole or monopole caused by the addition of conductors or circuit elements that change the input impedance or current distribution or both.
Log Periodic AntennaAny one of a class of antennas having a structural geometry such that its impedance and radiation characteristics repeat periodically as the logarithm of frequency.
Long Term Evolution (LTE)Also known as E-UTRA . Key 3G technology to ensure the competitiveness of UMTS and provide a high-data-rate, low-latency and packet-optimized system.
Long Term Evolution Advanced (LTE-A)Extension of E-UTRA. Achieves improvements in data rates using techniques such as Carrier Aggregation, enhanced use of multi-antenna techniquies, and support for Relay Nodes.
Loop AntennaAn antenna whose configuration is that of a loop. If the electric current in the loop, or in multiple parallel turns of the loop, is essentially uniform and the loop circumference is small compared with the wavelength, the radiated pattern approximates that of a Hertzian magnetic dipole.
Low Noise Amplifier (LNA)Receiving preamplifier having very low internal noise characteristics placed very near the antenna of a receiver to capture the C/N before it can be further degraded by noise in the receiving system.
LubLub is the interface between a Base Station and Radio Network Controller (RNC).
MAC AddressMedia Access Control address is the address associated with every hardware device on the network.
Main Beam/LobeRadiation lobe containing the direction of maximum radiation. In certain antennas, such as multilobed or splitbeam antennas, there may exist more than one major lobe.
Mean Side Lobe LevelThe average value of the relative power pattern of an antenna taken over a specified angular region, which excludes the main beam, the power pattern being relative to the peak of the main beam.
Mechanical TiltFixed angular shift in elevation of the antenna main beam axis by a change to the physical mounting.
MicrocellVery small cell used in densely populated areas where traffic volume is high. There is no official definition of what cell radius distinguishes a small cell from a microcell.
ModulationProcess of varying the characteristic of a carrier according to an information bearing signal. Varying one or more of the signal's basic characteristics -- frequency, amplitude, and/or phase.
MonopoleAn antenna, constructed above an imaging plane, that produces a radiation pattern approximating that of an electric dipole in the half-space above the imaging plane.
Multi-Beam AntennaAn antenna capable of creating a family of major lobes from a single non-moving aperture, through use of a multiport feed, with one-to-one correspondence between input ports and member lobes, the latter characterized by having unique main beam pointing directions. Often the multiple main beam angular positions are arranged to provide complete coverage of a solid angle region of space.
MultipathPropagation phenomenon characterized by the arrival of multiple versions of the same signal from different locations shifted in time due to having taken different transmission paths of varying lengths.
Multiple In Multiple Out (MIMO)Refers to using multiple antennas in a UE device to improve performance and throughput. The MIMO technology takes advantage of multipath or the use of orthogonal polarisations.
MultiplexA stream of all the digital data carrying one or more services within a single physical channel.
Multiplexer (MUX)Electronic component that selects one of several input signals and forwards the selected input into a single line.
NarrowbandClassification for the spectral width of a transmission system, typically one involving signals of a narrow range of frequencies.
Near Field PatternAny radiation pattern obtained in the near-field of an antenna. Near-field patterns are usually taken over paths on planar, cylindrical, or spherical surfaces.
Near-Field RegionThat part of space between the antenna and far-field region. In lossless media, the near-field may be further subdivided into reactive and radiating near-field regions.
Near Field Region, RadiatingThat portion of the near-field region of an antenna between the farfield and the reactive portion of the near-field region, wherein the angular field distribution is dependent upon distance from the antenna
Near Field Region, ReactiveThat portion of the near-field region immediately surrounding the antenna, wherein the reactive field predominates.
NoiseThe signal component resulting from undesirable communication channel signals.
Noise FigureFigure of merit for receivers and preamplifiers representing the amount of excess noise added to the signal by the amplifier or receiving system itself. The lower the noise figure, the less excess noise is added to the signal.
Noise FloorThe measure of the signal created from the sum of all the noise sources and unwanted signals within a system.
nLOSNear Line Of Sight
NLOSNon Line Of Sight
Null SteeringTo control, usually electronically, the direction at which a directional null appears in the radiation pattern of an operational antenna.
Null Steering Antenna SystemAn antenna having in its radiation pattern one or more directional nulls that can be steered, usually electronically.
Nyquist RateMinimum sampling rate proposed by Nyquist for converting a band limited waveform to digital pulses. The rate must be at least twice the highest frequency of interest in the waveform being sampled.
Omnidirectional AntennaAn antenna having an essentially non-directional pattern in a given plane of the antenna and a directional pattern in any orthogonal plane. Alternative: antenna system which radiates power uniformly in one plane with a directive pattern shape in a perpendicular plane.
Orthogonal Frequency Division Multiplexing (OFDM)Transmission method where the transmitted signal is composed of multiple narrow band OFDM-sub-carriers, all modulated in parallel.
OFDM SymbolTransmitted signal for that portion of time when the modulating amplitude and phase state is held constant on each of the equally-spaced carriers in the signal
Orthogonal PolarisationIn a common plane of polarization, the polarization for which the inner product of the corresponding polarization vector and that of the specified polarization is equal to zero.
Orthogonal Transmit DiversityForward link transmission method which distributes forward link channel symbols among multiple antennas and spreads the symbols with a unique Walsh or quasi-orthogonal function associated with each antenna.
PagingAct of seeking a User Equipment
Paging CycleThe individual time interval between monitoring Paging Occasion for a specific UE.
Paging OccasionPeriod in which UE listens to Paging Message for incoming traffic requests, system information changes, etc.
Paraboloidal ReflectorAn axially symmetric reflector that is a portion of a paraboloid.
Parasitic ElementA radiating element that is not connected to the feed lines of an antenna and that materially affects the radiation pattern or impedance of an antenna, or both.
PassbandFrequency band within which signals are transmitted by a filter without attenuation.
Path LossAmount of loss introduced by the propagation environment between a transmitter and receiver.
Peak PowerThe instantaneous power of the RF envelope which is not expected to be exceeded for [99.9%] of the time.
Pencil Beam AntennaAn antenna whose radiation pattern consists of a single main lobe with narrow principal half-power beamwidths and side lobes having relatively low levels.
PhasePhase is the current position in the cycle of something that changes cyclically.
Physical ChannelRF carrier that is modulated with information bits of the bursts.
Pilot ChannelUnmodulated, direct-sequence spread spectrum signal transmitted by a W/CDMA base station or mobile station. It allows the mobile stations to acquire the timing of the forward channel, serves as a phase reference for demodulation, and allows the mobile to search out the best (strongest) base stations for acquisition and hand-off.
Pilot PollutionType of co-channel interference in W/CDMA systems caused when the pilot code from a distant cell or base station is powerful enough to create an interference problem.
Plane Wave (Antenna)At any point in the far field of an antenna, the radiated wave can be represented by a plane wave whose electric field strength is the same as that of the wave and whose direction of propagation is in the radial direction from the antenna. As the radial distance approaches infinity, the radius of curvature of the radiated wave’s phase front also approaches infinity, and thus, in any specified direction, the wave appears locally as a plane wave.
Polarisation (Antenna)In a given direction from the antenna, the polarization of the wave transmitted by the antenna. When the direction is not stated, the polarization is taken to be the polarization in the direction of maximum gain.
Polarisation (Wave)In a specified direction from an antenna and at a point in its far field, the polarization of the (locally) plane wave that is used to represent the radiated wave at that point.
Polarisation DiversityDiversity technique where antennas of different polarizations, i.e., horizontal and vertical, are used to provide diversity reception. The antennas take advantage of the multipath propagation characteristics to receive separate uncorrelated signals.
Polarisation EfficiencyThe ratio of the power received by an antenna from a given plane wave of arbitrary polarization to the power that would be received by the same antenna from a plane wave of the same power flux density and direction of propagation, whose state of polarization has been adjusted for a maximum received power.
Polarisation MatchThe condition that exists when a plane wave, incident upon an antenna from a given direction, has a polarization that is the same as the receiving polarization of the antenna in that direction.
Polarisation Pattern (Antenna)The spatial distribution of the polarizations of a field vector excited by an antenna taken over its radiation sphere.
Power Reflectance of a RadomeAt a given point on a radome, the ratio of the power flux density that is internally reflected from the radome to that incident on the radome from an internal radiating source.
Power Spectral Density (PSD)A function of power versus frequency and when integrated across a given bandwidth, the function represents the mean power in such a bandwidth. By knowing the power spectral density and system bandwidth, the total power can be calculated.
Power Transmittance of a RadomeIn a given direction, the ratio of the power flux density emerging from a radome with an internal source to the power flux density that would be obtained if the radome were removed
Primary RadiatorThe radiating element of a reflector or lens antenna that is coupled to the transmitter or receiver directly, or through a feed line.
Processing GainRatio of the bandwidth of a spread spectrum signal to the bandwidth of the baseband signal.
PropagationProcess an electromagnetic wave undergoes as it is radiated from the antenna and spreads out across the physical terrain.
Propagation DelayLoss of time between the transmission and reception of a signal caused only by delays in the transmission medium itself. There are several terms (e.g. absolute delay, envelope delay, group delay) with nearly the same meaning.
Q (Antenna)Measure of the bandwidth of an antenna relative to the center frequency of the bandwidth.
Q-BandAlso known as V-Band, is a radio bandwidth range between 40 GHz to 50 GHz.
Quadrature Amplitude Modulation (QAM)Type of modulation where the signalling information is carried in the phase and amplitude of the modulated carrier wave. Specifically for QAM, the amplitude of two waves, 90 degrees out-of-phase with each other (in quadrature) are changed (modulated or keyed) to represent the data signal, in which each combination of phase and amplitude represents one of sixteen four-bit patterns.
Quadrature Phase Shift Keying (QPSK)Digital modulation scheme that conveys data by changing, or modulating, the phase of the carrier wave. QPSK uses four points on the constellation diagram, equispaced around a circle. With four phases, QPSK can encode two bits per symbol.
Radiated Emissions Measurement (REM)Measurement, typically tabulised, of ambient electric field strength at set distances from the transmitting antenna. Values are commonly used in consideration of safe RF exposure levels.
RadiationThe outward flow of energy from any source in the form of radio waves.
Radiation Pattern (RP)Diagram describing the power flux density in a given plane and at a constant distance from the antenna as a function of the angle from the zero degree reference direction
Radiation Pattern Envelope (RPE)An envelope below which the radiation pattern shall fit.
Radiating ElementA basic subdivision of an antenna that in itself is capable of radiating or receiving radio waves. Typical examples of a radiating element are a slot, horn, or dipole antenna.
RadiatorAny antenna or radiating element that is a discrete physical and functional entity.
Radio (Electromagnetic)Frequency within the electromagnetic spectrum normally associated with radio wave propagation. Electromagnetic waves whose frequencies are below 3,000 GHz.
Radio Frequency InterferenceRefers to the noise caused by other Radio Frequency that interferes with information being transmitted across unshielded copper cable.
RadomeA cover of dielectric material, intended to protect an antenna from the effects of its physical environment. May contribute to the overall performance of the antenna.
Rake ReceiverRadio receiver having multiple "fingers" and utilizing off-sets of a common spreading code to receive and combine several multipath (time delayed) signals, in effect using "time diversity" to overcome deep fades.
Radio Access Network (RAN)Ground-based infrastructure required for delivery of wireless communications services, including high-speed mobile access to the Internet.
Rayleigh FadingType of signal fading caused by independent multipath signals having a Rayleigh Probability Distribution Function.
Realised GainThe gain of an antenna reduced by the losses due to the mismatch of the antenna input impedance to a specified impedance.
Receive BandFrequency band which is used by one or more receivers paired with the transmitter
Receive ChainReceiver circuit with an associated antenna assembly.
Receive DiversityProcess of providing two independent receiving systems and spatially separated antennas to overcome fading effects on the radio signal.
Receive Signal Code Power (RSCP)Given only signal power is received, the average power of the received signal after despreading and combining.
Receive Signal Strength Indication (RSSI)Root mean squared (RMS) value of the signal received at the receiver antenna. The RSSI estimate is compensated for all the time-varying processes (such as automatic gain control) that affect the estimation procedure for obtaining a relative measure to
use in comparing the strength of signals received at different times
Receiver (Rx)Device on a transmission path which converts the signals as received from the transmission system into the signals required by the destination equipment. Alternate: An item of electronic equipment designed to receive electromagnetic radio frequency emissions.
Receiver Co-Channel RejectionMeasure of the capability of a receiver to receive a wanted signal, without exceeding a given degradation, due to the presence of an unwanted signal, both signals being at the nominal frequency of the receiver.
Receiver Noise FigureThe noise figure of the receiving system referenced to the receiver input.
Receiver OverloadingInterfering signal level expressed in dBm, above which the receiver begins to lose its ability to discriminate against interfering signals at frequencies differing from that of the wanted signal due to the onset of strong non-linear behaviour.
Receiver SensitivityAbility to receive a wanted signal at low input power level while providing a pre-determined level of performance.
Reed-Solomon CodeBlock-based error correcting codes with a wide range of applications in digital communications and storage.
Reference Signal Received Power (RSRP)The linear average over the power contributions (in Watts) of the resource elements that carry cell-specific reference signals within the considered measurement frequency bandwidth.
ReflectionIn an antenna, the redirection of an impinging RF wave from a conducting surface
Reflector ElementA parasitic element located in a direction other than forward of the driven element of an antenna intended to increase the directivity of the antenna in the forward direction.
Relay (Radio)Transmitter in a network that re-transmits a signal received off-air, either by simple frequency transposition or by regenerating the signal.
Relay Node (RN)A network element in the E-UTRAN, wirelessly connected to an eNode B and providing relaying function to UEs served by the E-UTRAN.
RepeaterA device that receives, amplifies and transmits the radiated or conducted RF carrier both in the downlink direction (from the base station to the mobile area) and in the uplink direction (from the mobile to the base station). A 'repeater' is a radio transceiver used to extend the transmission of a base station beyond its normal range.
Sampling RateNumber of samples of an analog signal that are taken per second to represent it digitally.
ScatteringThe random redirection of RF energy from irregular conducting surfaces.
ScramblingThe process whereby a sequence of data is made unintelligible.
SectorA geographical area resulting from the splitting of a cell achieved by the use of the sector antenna.
Sector AntennaAntenna system with a directive radiation in both azimuthal and vertical planes, typically utilised to cover a number of receivers in a geographic area.
Shadow FadingPhenomenon that occurs when a mobile moves behind an obstruction and experiences a significant reduction in signal power.
Side LobeA radiation lobe in any direction other than that of the major lobe.
Side Lobe SupressionAny process, action, or adjustment to reduce the level of the side lobes or to reduce the degradation of the intended antenna system performance resulting from the presence of side lobes.
Signal to Interference plus Noise Ratio (SINR)Ratio of the received strength of the desired signal to the received strength of undesired signals (noise and interference).
Signal to Noise Ratio (SNR)Ratio between the average power of signal and the average power of noise in a given point.
Simultaneous LobingA direction-determining technique utilizing the signals of overlapping lobes existing at the same time.
Slot AntennaA radiating element formed by a slot in a conducting surface.
Soft HandoverSoft handover is a category of handover procedures where the radio links are added and abandoned in such manner that the UE always keeps at least one radio link to the network.
Spectral EfficiencyDefined as the ratio between the peak gross-bit-rate and the occupied bandwidth. E.g. 10 b/Hz = 100 Mb/s data rate in a 10 MHz channel.
Steerable-Beam Antenna SystemAn antenna with a non-moving aperture for which the direction of the major lobe can be changed by electronically altering the aperture excitation or by mechanically moving a feed of the antenna.
SubcarrierCarrier wave modulated by a signal wave and then used with other subcarriers to modulate the main carrier wave.
SubreflectorA reflector other than the main reflector of a multiple-reflector antenna
SubscriberA user of a telecommunication service, based on a contract with the provider of the service.
Subscriber Identity Module (SIM)An integrated circuit card containing network related subscriber information.
Surge (Voltage)A transient voltage wave propagating along a line or a circuit and characterized by a rapid increase followed by a slower decrease of the voltage.
Synchronous-Code Division Multiple Access (S-CDMA)Multiple access physical layer technology in which different transmitters can share a channel simultaneously. The individual transmissions are kept distinct by assigning each transmission an orthogonal 'code'. Orthogonality is maintained by all
transmitters being precisely synchronized with one another.
Time Division Duplex (TDD)Transmission scheme that allows an asymmetric flow for uplink and downlink transmission which is more suited to data transmission. In a Time Division Duplex system, a common carrier is shared between the uplink and downlink, the resource being switched in time. Users are allocated one or more timeslots for uplink and downlink transmission.
Time Division Multiple Access (TDMA)Digital technology that enables a large number of users to access, in sequence, a single radio frequency channel without interference by allocating unique time slots to each user within each channel.
Transmit Diversity (Tx Diversity)Transmit diversity is based on space-frequency block coding techniques complemented with frequency-shift time diversity when four transmit antennas is used.
Transmit Power Control (TPC)Technique in which the transmitter output power is controlled resulting in reduced interference to other systems/users.
TransmitterEquipment, that allows to modulate a baseband transport stream and to broadcast it on one frequency.
Trellis CodeType of error correcting code for modulation.
Turbo CodeA high performance error correction coding scheme which has proven to be the most efficient in most cases.
Universal Mobile Telecommunications System (UMTS)The telecommunications system, incorporating mobile cellular and other functionality, that is the subject of specifications produced by 3GPP
UMTS Terrestrial Radio Access Network (UTRAN)Radio access network based on the UTRA standard term describing the Radio Network Controllers and Node Base stations of a UMTS network.
UplinkAn 'uplink' is a unidirectional radio link for the transmission of signals from a Mobile Station to a base station, from a Mobile Station to a mobile base station or from a mobile base station to a base station.
User Equipment (UE)A device allowing a user access to network services.
Vertical PolarisationA linearly polarised electromagnetic wave whose electric field vector is vertically polarized.
WaveguideForm of RF transmission line used for microwave applications. A system of material that is designed to confine electromagnetic waves in a direction defined by its physical boundaries. Typical types: Rectangular, Circular.
Whip AntennaA thin, flexible, monopole antenna.
Wireless Access Point (WAP)Also known as Access Point (AP), is a device that "connects" wireless communication devices together to create a wireless network. WAPs act as a central transmitter and receiver of WLAN radio signals. 
Wideband-Code Division Multiple Access (WCDMA)See: UMTS.
WiMAXWorldwide Interoperability for Microwave Access (IEEE 802.16x)
Wireless BridgeNetwork bridge which a least one of its portals resides on a wireless network. Typically refers to a microwave link.
Wireless ISP (WISP)A company that provides wireless Internet access for public. WISPs typically provide fixed-ethernet via wireless bridging, or install Wi-Fi wireless hotspots in airports, hotels and other public business places.
Wi-Fi Protected Access (WPA)Data encryption specification for 802.11 wireless networks. Uses an encryption method called Temporal Key Integrity Protocol (TKIP) to secure data transmissions.
Wi-Fi Protected Access 2 (WPA2)Enhanced version of WPA. It is the official 802.11i standard that was ratified by the IEEE in June, 2004. It uses the Advanced Encryption Standard (AES) instead of TKIP.
Yagi-Uda AntennaA linear end-fire array consisting of a driven element, a reflector element, and one or more director elements.
ZigbeeDefined in the IEEE 802.15.4, is the technology used in the low data rate Wireless Personal Area Network (WPAN) for home control, building automation industrial automation.


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  2. ETSI, TErms and Definitions Database Interactive (TEDDI), [Online], Available:
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  4. 3GPP SP-72, "Vocabulary for 3GPP Specifications (Release 13)", 3GPP, Valbonne, France, 3GPP TR 21.905 V13.1.0, Jun. 2016.