Wireless Technology Glossary


 

3G: Third generation mobile phones and telecommunications services standards meeting the International Mobile Telecommunications - 2000 (IMT-2000) specifications. IMT-2000 specifications require a minimum peak data rate of 200 kilobits per second. A number of radio interfaces are called 3G including UMTS, W-CDMA, HSPA+, CDMA2000, and TD-SCDMA.

4G: Fourth generation mobile phones and telecommunications services standards meeting the International Mobile Telecommunications - 2000 (IMT-2000) specifications. IMT-2000 specifications require a minimum peak data rate of 200 kilobits per second.

Access Pont (AP): A transmitting and receiving (transceiver) station that is part of that is part of a wireless local area network (WLAN).

Adaptive (Smart) Antenna: An adaptive antenna is one in which one or more characteristics can be modified to change some property of the antenna, such as the direction of a lobe or its directivity.

Adjacent Channel: A channel immediately next to another channel.

Adjacent Channel Interference (also see Interference): Adjacent channel interference occurs when signals from equipment from an adjacent channel are sufficiently-strong as to interfere with the primary channel´s equipment. Such interference often takes the form of desense of a receiver but can also result from modulation spurs that inadvertently appear in an adjacent channel.

Air Interface: The protocol by which a wireless device connects to a wireless service.

AMPS: Advanced Mobile Phone System. A first-generation cellular phone system using analog mobile phones, operating in the 800 MHz cellular FM band (former UHF TV channels 70 - 83). Now phased out in favor of GSM or CDMA2000.

Analog: Two popular types of analog modulation are Amplitude Modulation (AM) and Frequency Modulation (FM), technologies that occupy relatively-wide bandwidths and so have largely beed supplanted by new digital modulation techniques. AM is still used in the 530 - 1605 kHz AM broadcast band while FM is still used in the 88 - 108 MHz FM broadcast band.

Antenna: All transmitters and receivers require an "antenna" of some sort, which is a device by which electromagnetic waves ("radio" waves) are coupled into and out of a device.

Antenna Aperture: The aperture of an antenna is defined as how effective the antenna is at receiving RF energy. Also known as "effective area".

Antenna Directivity (aka "directivity"): The directivity of an antenna is its ability to concentrate RF energy in particular directions, much like focusing a light beam from a flashlight or floodlight. Although some small residual amount of light can be seen from the sides of the flashlight, most of the light energy has been focused in another direction where it can be best used. Directivity of an antenna is usually expressed in dB.

Antenna Gain: Antenna gain is the ratio of energy in a particular direction with respect to a reference antenna, usually isotropic, but sometimes with respect to a dipole antenna. Gain is usually expressed in dBi (gain with respect to an isotropic antenna, which has no directivity and thus no gain) or dBd (gain with respect to a dipole antenna, which two main lobes are 2.14 dB stronger than an isotropic antenna).

Antenna Efficiency: Antenna efficiency is affected by many factors, including construction technique and materials (conductor and dielectric losses), matching (loss due to reflections of RF energy between the antenna feedline and the antenna itself), location of the antenna (an antenna that must "look" through a building, structures such as towers, trees, shrubbery, etc. before it can "see" the other equipment´s antenna at the far end of the path will exhibit poor efficiency).

Antenna Lobe: A directional antenna has "lobes", in which RF energy is concentrated.

Antenna Matching: An antenna has a characteristic impedance which, for maximum efficiency, must be "matched" to the antenna´s feedline.

Antenna Polarization: Antennas radiate RF energy in the vertical plane, horizontal plane, or for circularly-polarized antennas, both planes.

 

Attenuation: Attenuation is the loss of intensity of radio waves.

Bandwidth: For an antenna, bandwidth is usually the range of frequencies over which the VSWR or another characteristic is measured. For example, bandwidth is usually expressed as the frequency range over which the gain is within 3 dB of the maximum, or the range of frequencies over which the VSWR is below a certain value such as 2:1 or 3:1.

Base Station: A radio at a fixed location providing services, such as access to the internet or e-mail, to more than one user, is referred to as the "Base Station".

Beamwidth: The beamwidth of an antenna is usually expressed as the number of degrees over which the main lobe is within 3 dB of the peak gain.

Billing Gateway: A Billing Gateway provides the ability to authenticate, bill,and control user sessions by collecting and analyzing IP traffic. It is a hardware box that is located either locally or somewhere in the network.

Bluetooth: A wireless technology operating in the 2400 - 2480 MHz band for interchanging data over short distances, typically less than 20 feet.

Bonded Copper: Combining several DSL circuits together to provide a boost in speed.

BREW (Binary Runtime Environment for Wireless): BREW is a software program (platform), originally developed by Qualcomm for CDMA "feature" phones (not "Smart" phones) to allow the development of applications such as games to be run on any BREW-enabled phone.

Broadband: Broadband is a relative term used to express the bandwidth of a data or other signal whose frequency range is wider than usual.

BTA (Basic Trading Area): A Basic Trading Area is a geographic area within a Major Trading Area (MTA) in the US that Rand McNally has designed to reflect business centers. The FCC has adopted the use of MTAs and BTAs for licensing Personal Communications Services.

Budget, Link (see Link Budget)

Cable Loss: All antenna feedlines (cables) exhibit a certain amount of RF energy loss, depending upon the cable´s dielectric and conductor loss as well as the cable´s dimensions. Cable loss should be minimized whenever possible as it reduces the strength of RF signals within the cable.

Carrier: A term used in either of two contexts:

  1. The operator or service provider that provides communications services.
  2. The primary signal from a transmitter is called the carrier. The carrier is then modulated so as to impart information or intelligence.

Carrier Frequency: The center frequency of a transmitter´s carrier, or primary signal.

CDMA (Code Division Multiple Access): Not to be confused with mobile phone standards W-CDMA, CDMA2000, or CDMAOne, CDMA is simply a channel access method using spread spectrum. Other channel access methods include FDMA and OFDMA.

CDMA2000: CDMA2000 is a mobile phone standard that supplanted CDMAOne (which used the IS-95 standard), and has, in turn, been supplanted by the W-CDMA standard.

CDMA2000 1XRTT: One of the family of CDMA2000 mobile phone standards. 1xRTT means "One times Radio Transmission Technology" and nearly doubles the capacity of IS-95 by adding another 64 duplex channels (1.25 MHz bandwidth per channel).

CDMA2000 EV - DO: One of the family of CDMA2000 mobile phone standards. EV-DO, also sometimes called simply EVDO or EV, means "Evolution-Data Optimized", and is a data transmission standard, typically for internet access. EVDO Rev. B, sometimes called "CDMA2000 3X", uses a pair of 3.75 MHz channels to provide increased data rates.

CDMA2000 EV - DV: One of the family of CDMA2000 mobile phone standards. EV-DV means "Evolution Data/ Voice" and its development was stopped in 2005 due to the lack of carrier interest, most of which had adopted EV-DO.

Cell: A basic geographical unit covered by a cell site. Also, a cell phone is sometimes referred to as simply a cell.

Cell Site: A geographical location where cell service equipment is located, such as radios and antennas.

Cell Splitting: A means of providing greater capacity within a cell by splitting the cell into smaller areas.

Central Office: Location of a telecom system´s hubs and switches.

Channel / Circuit: A range of frequencies over which a transmitter or receiver operate.

Circuit Switched Data (CSD): The original data access method for GSM networks, now replaced by packet based networks, e.g., GPRS, EDGE, etc.

CMRS (Commercial Mobile Radio Service) Provider: A commercial telecommunications company that provides wireless connection to the public switched telephone network, usually for profit. CMRS is a designation used by the FCC.

Co-Location: Also called Collocation, companies often coordinate the placement of wireless provider antennas within a single location such as on a single tower.

Co-Channel: When several RF links are using the same channel, they are said to be "co-channel".

Co-Channel Interference (aka "Crosstalk" also see Interference): When several RF links use the same channel, interference between them can occur, reducing data/voice speeds or preventing one or both links from communicating with the other end of their link.

Co-Polarization: Having the same polarization, such as two antennas both horizontally or both vertically polarized.

Coax (see Coaxial Cable)

Coaxial Cable: Coaxial cable is a form of shielded transmission line (aka feedline) consisting of a center conductor enclosed within a metallic shield with an insulating dielectric electrically isolating the two and maintaining the spacing. The center conductor can be made of many materials but most commonly, is either copper, or copper-plated steel which is usually also silver-plated for higher conductivity. Dielectric materials can be polystyrene, either dense-cell or blown, polyethylene, Teflon, and other such insulators. The outer shield can take many forms such as solid copper or aluminum (called "hardline"), corrugated aluminum or copper, aluminum foil, aluminum or copper braid or some combination of the two. The spacing between the inner diameter of the shield and the inner conductor determines the coax impedance. Coax is available in many impedances from 5 ohms to 125 ohms but the most common impedances are 50 and 75 ohms, the latter especially prevalent in cable TV applications while the former most common in wireless applications.

Coaxial Dipole Antenna: A dipole antenna, almost always vertically-polarized, in which one element, most often the lower or lower, is comprised of a quarter wavelength of shield, either by turning inside-out the shield of the coax itself or a separate quarter wavelength length of metallic tubing. The advantage of a coaxial dipole over an ordinary dipole is that the shield comprising the lower element tends to act as a "choke", preventing or greatly reducing unbalanced RF current from flowing on the coax shield.

Collinear Array Antenna: Co-linear means elements in the same polarization. An array of elements, such as dipoles or patches, that are all co-polarized (all in the same polarization) is called a collinear array.

Connector Loss: All connectors exhibit loss to some extent, from resistivity between pins or shields contacting one another, to dielectric losses between the individual conductors or pins. For example, pins or contacts that have been improperly attached to the wire or coax shield (incorrect crimping, poor solder joints, etc.) often exhibit higher-than-normal "connector loss".

Coverage Area: A geographical area that is "covered", or serviced, by a communications service or provider.

CPE (Customer Premises Equipment): Equipment provided by a communications service or provider that is owned by the service or provider, but is located at the customer´s facility or home; i.e., cable TV translator boxes, cable internet modems or routers, etc..

CPE Antenna: The antenna(s) used with Customer Premises Equipment.

Cross-Polarization: Antennas that radiate or receive in the same plane, such as horizontal or vertical, are said to be Co-Polarized. When they are in different polarizations, they are said to be Cross-Polarized.

dB: A logarithmic unit of measurement commonly used in the wireless or communications fields by which the ratio of power or voltage is expressed relative to a reference.

dBd: Logarithmic unit used to express antenna gain with respect to the gain of a dipole.

dBi: Logarithmic unit used to express antenna gain with respect to the gain of an isotropic antenna.

dBm: Logarithmic unit used to express power with respect to one milliwatt.

dBu (also dBuV): Logarithmic unit used to express voltage with respect to one microvolt.

dBV: Logarithmic unit used to express voltage with respect to one volt.

dBW: Logarithmic unit used to express power with respect to one watt.

Digital: A method for exchanging information or data using signals that are either on or off.

Directional Antenna: An antenna with directivity; i.e., a directional antenna concentrates its antenna in one direction.

Diversity: A communications system may use two or more antennas, sometimes in different polarizations, to avoid causing or receiving interference from other systems.

DSL (Digital Subscriber Line): A landline telephone line carrying high-speed digital signals for internet, e-mail, etc.

DSLAM (Digital Subscriber Line Access Multiplexer): A device used to connect multiple customers to a digital communications channel using multiplexing techniques.

DSSS (Direct Sequence Spread Spectrum): A modulation technique that spreads the signal further than the bandwidth actually required for the modulation itself.

Dual-Band: A device able to use two radio frequency ranges ("bands") is said to be a dual-band device.

Dual-Mode: A phone that uses two techniques for sending and receiving voice and data, such as GSM and CDMA.

E-Plane (also see H-Plane): The plane containing the electric field vector and direction of maximum radiation of a linearly-polarized antenna. The radio wave´s orientation or polarization is determined by the E-plane of the antenna.

EDGE: A data standard for GSM systems meaning Enhanced Data for GSM Evolution. Also known as W-CDMA although it is incompatible with CDMA itself. An EDGE-ready phone is required.

Effective Radiated Power (ERP): Effective radiated power is the power radiated by the antenna after all system losses and gains have been accounted for.

EIRP (see Equivalent Isotropically Radiated Power)

Equivalent Isotropically Radiated Power (EIRP): Effective Isotropically radiated power is the power radiated by an ideal Isotropic antenna after all system losses and gains have been accounted for.

ERP (see Effective Radiated Power)

ESMR (Enhanced Specialized Mobile Radio): ESMR is a digital radio that can do half- or full duplex, paging, fax, and data transmission, using a system of short-range repeaters. EMSR service is provided by Nextel and several other providers in the US.

ESN (Electronic Serial Number): The unique electronic serial number programmed into a wireless device.

Fade Margin: As a mobile wireless device moves around, its signal strength varies due to multipath, obstructions, signal absorption due to trees and bushes, and other such factors. The fade margin takes these effects into account and is counted as a loss in the Link Budget: The Link Budget is a set of calculations that take into account all the items that could affect the signal strength, either transmitted or received, of a RF path. A link budget will include the transmitter power, cable connector loss, cable loss itself, transmitter antenna gain, worst- and best case atmospheric conditions, receiver sensitivity, receiver antenna gain and cable and connector losses, etc. These calculations are performed using decibels.

Far-Field Region: Generally calculated as 2*(D2/λ) where D is the largest dimension of the antenna, and λ is free-space wavelength (same units as antenna dimension). The far-field region is where the antenna pattern is measured; the radiation pattern does not change shape with distance in the far field.

FDM (Frequency Division Multiplexing): A system whereby many individual signals are assigned to non-overlapping frequency bands.

FHSS (see Frequency Hopping Spread Spectrum)

Fixed Wireless Antenna: A fixed wireless link is one which connects only two fixed locations. Thus, each location typically has an antenna pointed at the other location, aka "fixed wireless antenna".

Free - Space Path Loss: Free - space path loss (aka FSPL) is the loss between two wireless links located in free space, as compared to the links being obscured by terrain or structures.

Frequency Bandwidth: The range of frequencies over which a particular characteristic, such as VSWR, is measured.

Frequency Band Division: A full-duplex wireless link uses two frequency bands. One transmitter transmits to the other receiver on either the high or low band while the other transmitter transmits to the other receiver on the low band. Often, the mobile transmitter uses the low band.

Frequency Hopping Spread Spectrum (FHSS): A technology whereby the transmitter and receiver "hop" from one radio channel to another according to a pseudo-random code.

Fresnel Reflection: When waves hit a surface with different refractive indices, a portion of the wave, called a Fresnel reflection, is reflected elsewhere.

Fresnel Zone: The Fresnel zone is regarded as the area between the radiating far field (usually defined as 2D2/λ) and the reactive near field (area immediately next to the antenna).

Front-to-Back Ratio (F/B): The ratio of the forward gain with respect to the reverse gain of an antenna, normally expressed in dB.

Full Duplex: Transmitting and receiving simultaneously.

GHz (Gigahertz): One billion (1x10^9) Hertz, or 1000 MegaHertz (MHz).

GPRS (General Packet Radio Service): A GSM-based packet data communications service.

GPS (Global Positioning Service): Worldwide satellite navigation system that continuously transmit time, location or other navigation signals. The GPS system comprises 24 satellites.

GSM (Global System for Mobile Communications): A technological approach to data transfer based on TDMA by which each unit is time-slotted within a cell.

Gain: An indicator of how well an antenna focuses its radiation from undesired directions to a desired direction. Antenna gain is expressed in either dBi or dBd.

Gain Pattern: The gain pattern of an antenna shows the radiation of the antenna in all directions. A gain pattern is usually normalized to that of a standard or reference antenna, in either dBi or dBd.

Gigahertz (see GHz)

HSCSD (High Speed Circuit Switched Data): An enhancement to the original Circuit Switched Data, the original data transmission method used for GSM phones. HSCSD provides up to 4 times faster data speed (38.4 kbit/s).

H-Plane (also see E-Plane): The plane containing the magnetic field vector and direction of maximum radiation of a linearly-polarized antenna. A vertically-polarized antenna usually has the H-plane in the horizontal plane, while a horizontally-polarized antenna usually has the H-plane in the vertical plane.

Half - Wave Dipole: An antenna consisting of two collinear elements end-to-end, fed out of phase at the center junction of both elements.

Handoff: The technique by which one cell´s equipment passes a mobile unit to another cell.

Hot Spot (see WiFi): A location where WiFi is publicly-available, usually without compensation, has come to be known as a "hot spot".

iDEN (Integrated Digital Enhanced Network): Developed by Motorola, iDEN is a mobile communications technology that provides users with trunked radio and cellular phone capabilities.

ISM (Industrial, Scientific, and Medical): A number of radio frequency bands have been designated for use by unlicensed industrial, scientific or medical devices. These range from as low as 6.7 MHz up through 24 GHz, with other, higher bands available upon local approval.

Infrared Communications: A technical approach to data transfer using the infrared spectrum of light, invisible to human eyes.

Input Impedance: The equivalent termination impedance of an electrical network as seen by a driving device.

Interconnection: The physical linking of one network with facilities or equipment not belonging to the first network.

Interference: An undesirable effect, such as loss of clarity, ghosting, distortion, or multiple signals overlapping one another, caused by another signal.

Interoperability: The ability of two systems, even when each uses different protocols or technologies, to inter-operate with one another.

Isolation: Expressed in dB, the ratio of power transferred from one antenna to another, or between two ports on the same antenna such as dual-mode or dual polarized.

Isotropic Radiator: A non-existent antenna with equal radiation in all directions.

kHz (kilohertz): One thousand Hertz or cycles per second, or 1 x 10^3 Hertz.

Kilohertz (see kHz)

LAN (Local Area Network): A computer network specifically intended to interconnect computers within a home, business, laboratory, school, etc.

LMDS (Local Multipoint Distribution System):

LTE (Long - Term Evolution): A standard for wireless communication based upon GSM/EDGE and UMTS/HSPA technologies. As LTE is incompatible with 2G and 3G technologies, it must be operated on separate wireless spectrum.

Lightning Arrestor: A device intended to prevent or reduce damage resulting from lightning strikes.

Line of Sight: Two antennas are said to be "line-of-sight" when they are able to "see" one another with no obstruction, such as a structure, trees, hill, etc..

Linear Array: A linear array has all radiating elements in the same plane.

Link Budget: A link budget is set up when planning a wireless link so as to insure there is sufficient signal that the link will be reliable. Transmitter power, connector and transmission line losses, antenna gain, distance of the link, receiver sensitivity, and fade margin are but a few of the items typically counted in a link budget.

Log-Periodic Antenna: A log periodic antenna is a very wideband array of collinear dipole elements, appearing much like a Yagi. The element length is calculated according to a logarithmic formula. Bandwidth can be as much as 10:1.

Major/Minor Lobe: The terms major or minor lobe refer to the lobes shown on antenna radiation or gain plots. The highest gain lobe is usually called the major lobe, and all other smaller lobes are referred to as minor lobes.

Mbps (Megabits per second): Data transfer rate of 1,000,000 bits per second; also equivalent to 125,000 bytes per second (one byte is eight bits).

Megahertz (MHz): One million Hertz, or 1 x 10^6 Hz. Also known as one million cycles per second.

Microstrip Antenna: An antenna created on a printed circuit board by etching or cutting the antenna element on one side, the other side being a ground plane.

Microwave Communications: Communications taking place generally at radio frequencies higher than 3000 MHz, or 3 GHz. The radio frequencies from 30 MHz to 300 MHz are generally considered VHF, while 300 to 3000 MHz (or 3 GHz) is generally considered to be UHF. 3 GHz to 30 GHz is considered to be microwaves.

Milliwatt (see mW)

MIN: Mobile Identification Number, or the wireless device´s phone number, not to be confused with the Electronic Serial Number which is assigned to each wireless device by the manufacturer.

MMDS (Multichannel Multipoint Distribution System): A licensed wireless service that provides broadband access.

MSA (Metropolitan Statistical Area): A geographical area with high population density such as a city and its surrounding suburbs. Two wireless service providers are licensed to operate within each MSA.

MTA (Major Trading Area): A Major Trading Area is a geographic area in the US that Rand McNally has designed to reflect major business centers. The FCC has adopted the use of MTAs and BTAs for licensing Personal Communications Services.

MTSO (Mobile Telephone Switching Office): The central computer that connects wireless phones to the public telephone network.

Multipath: When a RF signal arrives at an antenna from more than one direction (such as when it bounces off a structure or other unintended reflector), it is said to be multipath because it has arrived by following more than one path from the radiating antenna.

mW (milliwatt): One thousandth of one watt. When expressed in logarithmic ratio form, one milliwatt is also known as 0 dBm.

MVNO (Mobile Virtual Network Operator): A MVNO does not have its own networking equipment but rather, buys or leases networking capability from a provider in order to provide its own branded network services.

NAM (Number Assignment Module): The memory location within a wireless phone that stores the phone´s MIN and ESN.

Narrowband: A RF signal which modulation bandwidth is significantly less than the RF channel´s coherence bandwidth is called "narrowband".

Normalized Pattern: A normalized antenna gain pattern or plot has the peak gain set to 0 dB on the plot.

Null Filling: A technical means or method by which antennas are caused to fill in blind spots in a coverage area.

Number Portability: The process by which a mobile telephone number can be moved between wireless service providers.

OFDM (Orthogonal Frequency Division Multiplexing): A method of modulation whereby a large number of subcarriers are conventionally-modulated (QAM or PSK) at relatively slow symbol rates.

Ohm´s Law: A basic mathematical equation that expresses the constant relationship between voltage, current and electrical resistance.

Omnidirectional Antenna: A non-directional antenna; i.e., radiates equally in all azimuthal angles. A vertical ground plane is an example of an omnidirectional antenna.

PBX (Wireless Private Branch Exchange): The equipment that interconnects a business or organization´s internal telephones with the public telephone network.

PCS (Personal Communication Services): Any of several wireless data or wireless voice communications services combining a range of features and services.

PDA (Personal Digital Assistant): A portable device with a computer able to transfer data.

PIN (Personal Identification Number): A unique number sequence by which a person or device is recognized.

POPs: A standard set of definitions detailing the formatting of data in order to facilitate data transfer within and between networks and devices.

PSD (Packet Switched Data): A digital communications method whereby data is grouped into "packets" for further transmission through a network.

Packet (see Packet Data)

Packet Data: A method of transferring digital data by arranging data into small chunks.

Parabolic Reflector Antenna: An antenna that uses a reflector to gather and focus radio waves emitted by a feed-horn or other type of feed antenna into a sharper bean of waves than is otherwise possible. There are many types of reflector antennas such as flat plate, offset-fed, Gregorian and Cassegrain, etc. A parabolic reflector has a curved shape that follows the mathematic expression for parabolic curves.

Path Loss (see Free Space Path Loss)

Path Planning: Successful wireless links require planning the geographic path from end to end so as to avoid, insofar as possible, obstructions such as buildings and other structures, trees and shrubbery, high terrain, etc., all of which introduce RF signal loss by reflecting the signal in other directions or absorbing the signal.

Point-to-Point Network: A point-to-point network transfers data from one geographical location to another.

Point-to-Multipoint Network: A point-to-multipoint network transfer data from one geographical location to a number of others, such as in a "star" configuration.

Polarization: The orientation, relative to the earth, of the electric field of a radio wave.

Power Handling: The capability of an antenna to handle high power without failure.

Radiation Efficiency: Radiation efficiency is the efficiency with which an antenna radiates a radio wave.

Radio Waves: The interaction between the e-field and h-field of an antenna create RF energy, sometimes called "radio waves".

Repeater: A repeater is a receiver-transmitter system that repeats, or duplicates, a received signal. Repeaters are used to extend the range of low-power or low height radios.

RFP: Request For Proposal

Radio Bands: The range of frequencies used for particular radio services. For example, FM broadcast operates between 88 and 108 MHz, which is commonly called the FM broadcast band.

Roaming: When a wireless mobile device establishes connectivity outside of the "home" geographical area where it was registered, it is said to be "roaming".

RSA (Rural Service Area): One of the rural markets within the US outside of a Metropolitan Service Area (MSA). These areas are designated by the FCC.

SMS (Short Messaging Service): SMS is a wireless text service, typically limited to 160 characters.

SNR (Signal - to - Noise Ratio): A scientific measure comparing the strength of a desired signal to background noise. Normally expressed in a logarithmic ratio using decibels (dB).

Satellite Communications: Communications taking place through a satellite.

Selectivity: A technical term referring to the ability of a receiver to reject undesired signals.

Sensitivity: A technical term referring to the ability of a receiver to detect and decode weak radio signals.

Side Lobe Level: A technical term referring to the gain level of other than the main lobe of an antenna.

Side Lobe Suppression: Side lobes can be suppressed by proper phasing of several antennas, or by aiming an antenna so that the side lobes are not pointing toward an interfering signal.

Signal - to - Noise Ratio (see SNR)

Smart Antenna (see Adaptive Antenna)

Smart Phone: A mobile wireless telephone with many other features such as PDA, camera, e-mail, web browsing, etc.

Spectrum Allocation: The electromagnetic spectrum is divided up into frequency bands in which particular uses or users are allowed. These are known as spectrum allocations.

Spectrum Analyzer: A test equipment that is capable of showing the presence of radio frequency signals within a particular frequency range.

Spectrum Assignment: Certain portions of the electromagnetic spectrum are assigned to certain users; these are are known as spectrum assignments.

Spread Spectrum: A communications technique by which a transmitted signal is spread out in frequency more than is necessary to carry its modulation.

TCP/IP (Transmission Control Protocol/Internet Protocol): A set of communication protocols used to define communications with the Internet and other networks.

TDMA (Time Division Multiple Access): A channel access method allowing many users to utilize the same frequency by dividing the signal into particular time slots.

Third-Generation (see 3G)

Tower(s): Wireless base station antenna systems are often erected on towers or other preexisting structures such as electric company transmissions line towers.

Transceiver: A radio whose transmitter and receiver circuitry is mostly shared is known as a "transceiver".

Tri-Band Handset: A mobile wireless phone that covers three wireless bands, such as 800, 900 and 1900 MHz.

Tri-Mode Handset: A typical trimode handset can support CDMA, WiFi, and WiMAX.

UMTS (Universal Mobile Telecommunications Systems): A third-generation mobile wireless communication technology based upon GSM.

VoIP (Voice over Internet Protocol): A telephone communications technology that conducts phone conversations over the internet.

Voice Recognition: Smart phones now may include voice recognition technology whereby various commands may be spoken to the phone to perform tasks such as looking up and dialing a particular phone number.

VRRP: Virtual Router Redundancy Protocol, a computer networking protocol that dynamically assigns responsibility for a virtual router to one of the routers on a LAN. An election protocol allows another router to take over if the Master router fails.

Voltage Standing Wave Ratio (VSWR): The ratio of the amplitude of a reflected wave from a load to the incident wave.

WAN (Wide Area Network): A communications network that combines together a number of LANs (Local Area Networks).

WAP (Wireless Application Protocol): A technical standard allowing information transfer over a mobile wireless network.

WISP (Wireless Internet Service Provider): An entity providing wireless networking capability.

W-CDMA (Wideband Code Division Multiple Access): An air interface standard of the UMTS family used in 3G telecommunications networks.

Wavelength: The distance over which a wave´s shape repeats, usually expressed in meters, centimeters or millimeters.

Wi-Fi (Wireless Fidelity): A means of enabling interconnection of a number of wireless devices over a short range, such as a Local Area Network (LAN).

Wi-Max (Worldwide Interoperability for Microwave Access): A means of providing high speed wireless connectivity to a large number of users over a wide geographical area; sometimes called "WiFi on steroids".

Wind Loading: The size of an antenna or other outdoor-mounted component affects it´s "wind loading", which is the amount of exposed surface area presented to the wind. Antenna and radio supports must be designed to support equipment at a given wind speed, often stipulated by local regulations.

Wireless Access Point Antenna: Antennas connected to wireless access equipment. Such antennas may be either omni-directional or directional depending upon the requirement.

Wireless Internet: Internet connectivity using wireless equipment and protocols.

Wireless ISP (see WISP)

WLAN (Wireless Local Area Network): A local area network using wireless technology (such as WiFi or Bluetooth) rather than wires.

WLL (Wireless Local Loop): A system connecting users to the local public access telephone network.

Yagi or Yagi-Uda Antenna: An antenna usually consisting of a driven element, reflector and one or more director elements mounted on a "boom". Yagis can be made from 2 elements to boom lengths as long as 10 wavelengths long (after which the principle of "declining returns" begins to come into play).