Glossary terms on RF and Wireless | RF and wireless glossary

This page covers glossary of terms (i.e. terminologies) on RF, Wireless, DSP and data communication domains. This RF and wireless glossary is very useful for beginners as well as experts in RF/Wireless domain.

A Access Point

A network device, or communication hub, which connects wireless devices (Stations) to a wireless local area network (WLAN). Basically it provides access to resources of Wi-Fi network to Stations requesting to join the network.
AES
Advanced Encryption Standard used in many systems for providing security to the user of data, voice and other services. AES supports key lengths ranging from 128 to 256 bits.

Air Interface
The medium between Base station(BS) and Subscribers(or wireless devices viz. tablet, mobile requesting for some services from BS) used mainly by RF Frequency OR medium between wireless Access point and Stations.
Analog
In telecommunications, an early wireless network technology involving the modulation of radio signals, which transmit information as sound waves over radio signals allowing one call per channel.
ANSI
The American National Standards Institute. A standards-setting, non-governmental organization that develops and publishes standards for transmission codes and protocols for use in the United States.
API
Application Programming Interface. A set of standard methods or functions that application programs can use to access a particular set of services or tools, For example network services and program-to-program commands.
Asynchronous
Communication signals which do not depend on a shared timing mechanism to transmit and receive information.
Attenuation
A loss of signal strength which is traversing some medium. Usually measured in dB.
AWGN
Additive White Gaussian Noise, It is additive noise present in the signal due to thermal noise and other noises present in the atmosphere. It is Gaussian distributed having mean of 0 and variance of 1.

B
Backhaul
Basically this part are the systems which connects wireless network connectivity with internet highway (or Packet Data Network) to provide voice and data services to the user.
Band
In wireless communications, a frequency or contiguous range of frequencies is called band.
Bandwidth
Range of frequencies is called as Bandwidth.
Analog bandwidth is measured in hertz (Hz). Digital bandwidth is the volume of data that a channel can carry and is measured in bits per second (bps).
Base Station
It is called a cell tower or a cell site. A base station is a transmitter/receiver location that establishes radio links between Subscribers or wireless devices. The base station includes an antenna tower, transmission radios and radio controllers. Each geographic area in a cellular network requires a base station.
Baseband Signal
An Un-modulated signal usually is called baseband signal. Its frequency range will be around 0 Hz. Complex Signal before DAC/Frequency conversion is termed as baseband signal.
Beacon
To keep the network synchronized, access points or stations broadcast a type of packet called as Beacon. Also in satellite communication, satellite reserve a carrier called beacon carrier which is used for antenna alignments on the earth.
BER
Bit Error rate, It is the measure of quality of the telecommunication link from one end to the other end. It is the ratio of bits in error to the number of total bits transmitted.
Bit Rate
It is the speed at which the data is transmitted over the medium. Usually measured in bits per second.
BPSK
Binary Phase Shift Keying, it is the digital modulation technique. Here only two phases of the carrier frequency are used to represent digital data i.e. one ('1') and zero ('0') is represented by 180 degree and 0 degree respectively. Hence only 1 bit is represented by carrier in one time period.
Bluetooth
A short-range wireless technology that interconnects devices such as phones, computers, keyboards, microphones and mice. Bluetooth supports both voice and data communications.
BPS
Its full term is Bits Per Second. The standard for measuring the smallest unit of information in digital communications and data processing applications.
Broadband
Generic term for high-speed digital Internet connections, such as wireline, DSL or cable modems and wireless third-generation technologies.
BSID
Base Station Identifier, the unique number given to the Base Station for identification in the wireless networks.
BSC
Base Station Controller. A component of a base station subsystem, the BSC supervises the functioning and control of multiple BTSs.
BTS
Base Transceiver Station. It includes Transmitter, Receiver and the antenna systems. This part of wireless network which interacts with cellular phones and internet devices.

C
C Programming
It the programming language used mainly for embedded applications requiring more interaction with hardware.
Carrier
In wireless communications, an electromagnetic pulse or radio wave transmitted at a stable base frequency. It will be usually higher radio frequency. Used to transmit baseband signals to long distance using antenna.
CCDF
Complimentary cumulative distribution function, used as a measure of variation in the power of baseband signal at the baseband Transmitter. A CCDF curve is a plot of relative power levels versus probability. This will determine what specifications of Power Amplifier (PA) need to be designed or to be used in the transmitter.
CCITT Consultant Committee on International Telephone and Telegraph - An international organization which develops standards and defines interfaces for telecommunications.
CCK
Complimentary Code Keying- A modulation scheme that transforms data blocks into complex codes and is capable of encoding several bits per block. Mainly used in 802.11b Physical layer for 5.5 and 11 Mbps rates.
Convolution Codes
Convolution codes are a class of codes which can detect and correct errors. Mainly used in wireless systems viz. WLAN, WiMAX, LTE and Satellite communications where channel is random and time varying. This will add some amount of redundancy to the data but makes the system power efficient.
CRC
Cyclic redundancy check. It is a check sum on integers (modulo-2 Sum) and it's a common error detection and not correction, protocol used in data communication. Almost all the MAC layers possess this concept.
CTS
Clear to send (CTS) a signal from the receiving station to the transmitting station granting permission to transmit data. In a wireless network a station responds to a RTS with a CTS frame, providing clearance for the requesting station to send data. Used in 802.11agn.
CDG
CDMA Development Group. An international consortium of companies working together to lead the adoption and evolution of CDMA-based wireless systems around the world.
CDMA
Code Division Multiple Access. A digital wireless technology that works by converting analog information, such as speech, into digital information, which is then transmitted as a radio signal over a wireless network. CDMA uses spread-spectrum technology, which spreads the information over larger band, hence provides security as the information will be embedded below noise power. Walsh codes are used for the same.
Cell
The geographical area served by one Base station, calculated based on signal power level sufficient to provide reliable connection to the subscribers.
Cellular
Analog or digital communications that provide a consumer with a wireless connection from the mobile device to a Base Station.
Channel
The amount of wireless spectrum occupied by users or end devices. Similar to Bandwidth.
Circuit-Switched Network
Networks that temporarily establish a physical circuit "connection" and keep that circuit reserved for the user until a disconnect signal is received. A dial-up modem is an example of a circuit-switched connection used for internet connection.
Cyclic Prefix
One of the main advantages of OFDM is its effectiveness against the multi-path delay spread frequently encountered in Mobile communication channels. For this, portion of each OFDM symbol is extracted from the end and appended at the beginning. This portion usually kept greater than the delay spread of the channel and is called as cyclic Prefix.

D
DAC
Digital to Analog Converter, An electronic device or a piece of software, often integrated , that converts a digital number or signal into a corresponding analog voltage or current.
DAMA
Demand Assigned Multiple Access - a technique for sharing satellite bandwidth among many users based on demand. This makes use of bandwidth more efficiently as the allocation is made based on the demand and not reserved permanently.
Decibel
A unit for expressing a logarithmic measure of the ratio of two signal levels. It is most commonly used for expressing power, voltage and current ratios as follows:
Power Ratio dB = 10 log (P1/P2)
Decoder
A piece of hardware or software that decodes the encoded data into the original format.
Demodulator i.e. De mapper
A piece of hardware or software that demodulates the modulated data back to raw bit format.
Digital
A form of transmission that transforms analog signals, such as voice, into a series of electrical or optical pulses that represent the binary digits 0 and 1.
DSP
Digital Signal Processing, a technique employed mainly for speech and data processing in today's advanced wireless communication systems.
DOT
Department of Telecommunications. The India Government body that covers policy, licensing, and coordination of telegraphs, telephones, wireless, data, facsimile and telemetric communications.
Downlink
The connection from the network to the end-user communication device. In satellite communications, also refers to the connection from a satellite to a terrestrial receiver or VSAT or ground station or earth station. In wireless communications, also refers to the connection from Base station to subscriber station. Also known by Forward link in some wireless systems.
Dual Mode
Functionality that allows a mobile phone to operate in two different modes for greater roaming capabilities. For example, a mobile phone may be equipped to support both CDMA2000 and WCDMA standards to send and receive calls.

E
EDGE
Enhanced Data Rates for Global Evolution. A software/hardware enhancement for existing GSM networks designed to provide higher data rates to enhance the delivery of multimedia and other broadband applications.
Embedded
In wireless communications, used to describe capabilities, such as Internet access, that is housed in a device.
Ethernet
Ethernet has evolved through a number of iterations to support increasingly higher speeds. Ethernet is defined for a variety of physical media, such as category 5 copper, multi-mode fiber and single-mode fiber.
Encoder
A piece of hardware or software that encodes the data i.e. accepts the message bits and adds redundancy according to a prescribed rule.
Equalization
Equalization is the process to shape the received pulses so as to compensate the effects of amplitude and phase distortions caused by imperfections in the transmission characteristics of the channel. The term mainly used in channel equalization techniques.
EVM
The error vector magnitude or EVM (sometimes also called receive constellation error or RCE) is a measure used to quantify the performance of a digital radio transmitter or receiver. EVM is a measure of how far the constellation points are from the ideal locations.
eNodeB
Denotes the base transceiver station (BTS) in LTE technology. Also termed as eNB.

F
FCC
Federal Communications Commission. The U.S. government agency responsible for regulation of the communications industry.
Fading
The variation in received signal's amplitude due to interference is called as fading.
FHSS
Frequency Hopping Spread Spectrum. A technique used in radio transmission systems, such as wireless local area networks (WLAN) and select mobile networks. FHSS converts a data stream into a stream of packets which are then sent in short bursts via transmitters and receivers that move or "hop" from one frequency to another. The hopping sequence is known at both transmitter and receiver. Mainly used for security reasons.
Firewall
A combination of hardware and software that protects a computer or group of computers from an attack by an outside network or computer user.
Frequency
The rate at which an electromagnetic waveform alternates. Usually measured in hertz (Hz) or megahertz (MHz).
Frequency offset
Frequency offset is defined as the difference between the ideal frequency and measured frequency.
Forward error correction(FEC)
A technique used in wireless communication system to make the system power efficient by way of correcting the errors both at bit and block levels. For example Convolutional encoder, Reed Solomon encoder are called as FEC techniques.

G
Gateway
A network point that acts as an entrance to another network. It is the interface between two heterogeneous networks.
GB
Gigabyte. A measure of computer data storage capacity. Measured as approximately a billion bytes as 1GB.
GHz
Gigahertz. A measure of frequency equal to a billion hertz or a thousand megahertz (MHz).
GPRS
GPRS is a packet-linked technology that enables wireless internet and other data communications. GPRS provides more than four-times faster speeds than conventional GSM systems.
GPS
Global Positioning System. A worldwide radio-navigation system developed by the U.S. Department of Defense to enable users to determine their exact location anywhere on the globe from land, air or sea. GPS works via radio signals sent from orbiting satellites to receivers on the ground.
GSM
GSM, first introduced in 1991, is the leading digital cellular system. It uses narrowband TDMA (Time Division Multiple Access). Eight simultaneous calls can occupy the same radio frequency using TDMA as each frequency band is used by eight time slots.

H

Handoff
The process, invisible to the user, of transferring a cellular phone conversation from one base station (cell tower) to another without interruption to the call. Handoffs exist at various levels in wireless network. For example, in GSM network it can be between BTS and BTS, between BSC and BSC or between MSC and MSC.
Handset
A wireless device that contains a transmitter and receiver. Also known as a cell phone or mobile phone.
Hard Handoff
A handoff is the process, invisible to the user, of transferring a cellular phone conversation from one base station (cell tower) to another without interruption to the call. Hard handoffs require that the connection of a cellular phone call be broken in the original base station before the connection can be made in the next base station. A hard handoff may result in a dropped call sometimes.
Hertz
The international unit for measuring frequency, equivalent to cycles per second. One megahertz (MHz) is one million Hertz. One gigahertz (GHz) is one billion hertz.
HSDPA
HSDPA (High-Speed Downlink Packet Access) is specified in 3GPP Release 5. With HSDPA, WCDMA has been extended with additional transport and control channels, such as the high-speed downlink shared channel (HS-DSCH).
HSUPA
High-Speed Uplink Packet Access. An enhancement to WCDMA networks that provides higher data speeds in the uplink to support applications such as VPN access and large file transfers.

I
IEEE
Institute of Electrical and Electronics Engineers. A standards body responsible for developing computing and electronics standards. The IEEE developed 802.11 and 802.16 standards for WLANs (wireless local area networks) and WiMAX, which are widely followed today for broadband community.
IEEE 802.11
WLAN technologies complement access technologies for broadband networks.
IETF
Internet Engineering Task Force. The body that defines standard Internet operating protocols such as TCP/IP.
IP
Intellectual Property - a proprietary design which companies license so that others cannot copy.
IM
Instant Messaging. Instant, real-time, text-based communication between two or more people over a network such as the Internet.
IQ signal
Abbreviated for "in-phase and quadrature-phase of the signal" Signals that are fundamental products of individual In-phase and quadrature modulators, which are exactly 90 degrees out of phase.
Interoperability
The ability of heterogeneous systems and networks to communicate and co-operate through specified standards.
Internet Protocol
The Internet Protocol specifies the format and address scheme of information packets sent over the internet. IP allows you to label a package with the destination address of the receiver and have the network carry the packet to that destination, but there's no direct link between sender and receiver (IP is a 'connectionless' protocol).
When combined with specific higher-level protocols - such as Transport Control Protocol (TCP) -
a virtual connection is established between two hosts so that reliable data connection can be established between the two.
ISDN
ISDN is a set of standard specifications for access technologies and services built on traditional PSTN networks for enhanced and integrated voice and data communication.
ISO
International Organization for Standardization.
IT
Information Technology
ITU
International Telecommunications Union. An agency of the United Nations with the goal of establishing telecommunication standards.

J:
Java
A programming language developed by Sun Microsystems for creating and running software programs on a single computer and in networked environments, such as the Internet. Java programs are portable and can be run anywhere in a network that has a Java virtual machine (JVM).
JPEG
A standard file format for image compression, typically for photographic images. Commonly used to store and transmit photographs over the Internet. The most common file extensions for this format are .webp or .jpeg.
JVM
Java Virtual Machine. Interprets compiled Java code for a computer's processor so it can execute a Java program's instructions.
Jamming:
Jamming is defined as intentionally transmitting signals in a particular frequency band to disrupt reception of signals.
K
KB
Kilobyte. A measure of computer memory or storage. Measured as 1,024 bytes in decimal notation.
Kbps
Kilobits per second. Commonly used as a speed for data transmission. Measured as 1,000 bits per second.
Kilohertz (KHz)
One thousand hertz. A measurement often used to reference radio frequencies.
L
LABVIEW
Labview is a programming language mainly used for data acquisition and Graphical User Interface. Developed by National Instruments.
LAN
Local Area Network. A small communication network covering a limited area, such as within a building or group of buildings.

Last Mile
Commonly used in telecommunications to refer to the final delivery of communications connectivity between the network and the end user's point of access (home or business).
Line of Sight
In line of sight transmission the transmitting and receiving stations (antennas) can see each other. It's a clear path between transmitting and receiving stations.
LTE
Long Term Evolution, it is a standard for wireless communication of high-speed data for mobile phones and data terminals. The standard is developed by the 3GPP (3rd Generation Partnership Project). It is also called as 4G and is the future mobile broadband cellular system.
M
MATLAB
MATLAB is a high-level language and interactive environment that enables you to perform computationally intensive tasks faster than with traditional programming languages.
MAC
Medium Access Control layer is the lower layer in OSI model prior to PHY layer. The primary functions of the MAC layer is to control and access the physical medium, and also performs fragmentation and de fragmentation of packets. It also takes care of scheduling and priority handling.
Microwave
The electromagnetic waves of very high frequency mainly used in wireless communication.
MB
Megabyte. A measure of computer processor storage and real and virtual memory. Measured as 1,048,576 bytes in decimal notation.
Mbps
Megabits per second. Measured as one million bits per second. A measurement of the amount of data transferred in one second between two telecommunication points.
MHz
Megahertz. One million hertz or cycles per second. A measurement often used to describe the speed of digital and analog signals.
MIMO
Multiple Input, Multiple Output. In wireless communications, an antenna technology that uses multiple antennas at the source (transmitter) and the destination (receiver). This will increase the data rate/robustness based on the technique employed at the transmitter.
Modulator-i.e. Mapper
It is the technique which will change amplitude, frequency or phase of carrier wave in accordance with the modulating or baseband signal.
MSC
Mobile Switching Center. A sophisticated telephone exchange that provides mobility management services, such as circuit-switched calling, and coordination between base stations (cell towers), networks and mobile users within a network.
Multicast
Simultaneous transmission of content from a single source to large numbers of wireless subscribers. Usually refers to the delivery of a wide variety of TV-like programming to wireless devices.
Multipath
The multiple paths a radio wave may follow between transmitter and receiver. In cellular communications, refers to a radio signal reaching the receiving antenna by two or more paths.
Multipath Fading
Interference during wireless signal reception caused by the deflection of a radio signal off obstacles such as buildings, mountains and other large obstructions.
Multiplexing
Multiplexing is a technique where multiple channels are combined for transmission over a single transmission path. Mainly TDM and FDM is used.

N
Node
A point of connection into a network. In packet-switched networks, a node is one of the many packet switches that form the network's backbone.
Node B
Denotes the base transceiver station (BTS) in WCDMA technology.
Noise
Unwanted signal superimposed on a true signal.
O
OEM
Original Equipment Manufactuer. The manufacture of a device (often a consumer electronics product).
OFDM
Orthogonal Frequency Division Multiplexing. A wireless communications technology and modulation technique that divides available spectrum into multiple radio frequency (RF) channels. IEEE standards 802.11a, 802.16 use this technique for transmission of data. This allocates resources to the users in time plane.
OFDMA
Orthogonal Frequency Division Multiple Access. This allocates resources to the users both in time and frequency grid.
Operating System (OS)
Software that manages the basic operations of a computer system. Examples include UNIX, Windows, Palm OS and Mac OS X.
Operator
A wireless network operator, also often referred to as a carrier or service provider, which provides mobile telecommunication services.
OSI
Open Systems Interconnection. A reference model established by the ISO to provide a network design framework that allows equipment from different vendors to be able to communicate using set of protocols.

P
Packet
A digital "package" of data that enables efficient use of radio spectrum and routing over a network, such as the Internet or wireless networks. Each packet is numbered separately and includes the Internet address of the destination.
Packet-Switched Network
Networks that transfer digital packets of data. Packet-switched networks are connectionless or "always on," eliminating the need to connect to a network to send or receive data. In contrast, circuit-switched networks require a dedicated circuit, or connection, for the duration of the data transmission.
PCMCIA
Personal Computer Memory Card International Association. An international association that standardizes credit-card sized wireless modems which can be inserted into laptops or other mobile computing devices to connect to the Internet. A Type II PC card is the most common PCMCIA card.
PER
Packet error rate (PER) is an average fraction of transmitted packets that are not detected correctly.
Phase Offset
Difference in reference phase of transmitted waveform and received waveform is called phase offset, expressed in degree.
PCS
Personal Communications Services. Refers to the 1900 MHz cellular frequency band. More commonly used as a marketing term to describe digital wireless services in the Americas, regardless of the particular frequency band being used.
PDA
Personal Digital Assistant. A portable personal computing device used for text messaging, email, calendar, contacts and a wide range of other applications.
PHY
Physical Layer. Transmits raw bits of data by establishing and terminating connections to a networked communications resource. Refers to network hardware, physical cabling or a wireless connection. Considered layer one of the seven-layer OSI (Open Systems Interconnection) model of data communications.
Pilot
A single frequency signal which is transmitted for synchronization or reference purposes.
Preamble
A predefined pattern known both at Transmitter and Receiver used for synchronization purpose, mainly for time, frequency synchronization and channel estimation-equalization.
Project
A project is a temporary endeavor undertaken to create a unique product, service, or result.
Program
A program is defined as a group of related projects managed in a coordinated way to obtain benefits and control not available from managing them individually.
PPP
Point-to-Point Protocol. A protocol for communication that allows two devices to transport packets over a data connection, such as a personal computer connected by phone line to a server. ( See Also: Packet)
Protocol
Within the context of data communications, a specific set of rules related to data transmission between two devices. Protocols set standard procedures that enable different types of data devices to recognize and communicate with each other.
PSTN
Public Switched Telephone Network. Refers to the local, long-distance and international phone system. In the United States, PSTN refers to the entire collection of interconnected phone companies.

Q
QAM
Quadrature Amplitude Modulation, where carrier signal's amplitude as well as phase is varied in accordance to the information bits. In the case of 16QAM, 4 bits represented by one carrier.
QoS
Quality of Service. A measure of network's transmission reliability and efficiency. QoS is commonly used by network operators to indicate a higher level of service guarantee to customers.
QPSK
Quadrature Phase Shift keying. A modulation method that encodes two bits as each carrier phase shift.
R
Randomization
A technique used in digital baseband chain used to remove long string of 1's. Basic randomization circuit is Ex-OR gate.
Receiver sensitivity
Ability of the receiver to work satisfactorily to the minimum of power level.
Reverse Link - a.k.a. Uplink
The connection from the end-user communications device to the network. In satellite communications, also refers to the connection from a terrestrial transmitter (ground Station) to a satellite. In wireless communication it refers connection from Subscriber to the BS.
RF
Radio Frequency. Measured in Hertz, MHz and GHz. Wireless and cordless telephones, radio and television broadcast stations, satellite communications systems and two-way radio services all operate using radio frequencies.
RFID
Radio Frequency Identification. A method of remotely retrieving data from and storing data associated with animals, people, products or equipment. Requires an RFID tag which contains an antenna to enable the tag to send and receive queries from an RFID transceiver.
RJ-11
Standard 4-wire connectors for phone lines. Standard 4-wire connectors for phone lines.
RJ-22
Standard 4-wire connectors for phone lines with secondary phone functions (such as call forward, voice mail, or dual lines). Standard 4-wire connectors for phone lines with secondary phone functions (such as call forward, voice mail, or dual lines).
RJ-45
Standard 8-wire connectors for networks. Also used as phone lines in some cases. Standard 8-wire connectors for networks. Also used as phone lines in some cases.
RNA
Remote Network Access: Terminology being used for the hardware/software for connecting remote workers, offices, customers and suppliers through non-dedicated (dial-up/ISDN) connections. - Remote Network Access; Terminology being used for the hardware/software for connecting remote workers, offices, customers and suppliers through non-dedicated (dial-up/ISDN) connections.
Roaming
The ability to access a network anywhere and move freely while maintaining an active link through a wireless connection to a network. Roaming usually requires a handoff when a node (user) moves from one cell to another. The ability to access a network anywhere and move freely while maintaining an active link through a wireless connection to a network. Roaming usually requires a handoff when a node (user) moves from one
cell to another.
Router
A device that interconnects two dissimilar networks. For example, it connects LAN with WAN.
RNC
Radio Network Controller. Equipment in third-generation (3G) wireless networks that interfaces with the core network, controls the radio transmitters and receivers in Node Bs, and performs mobility functions.
ROI
Return On Investment. A financial performance measure to determine the relative attractiveness of a proposed investment. ROI is typically measured in dollars but can also be measured by less quantifiable benefits such as increased customer satisfaction.

S
SDK
Software Development Kit. A set of software tools, usually designed for use with a particular operating system, that enables software developers to write programs that will work on the target operating system.
Service Provider
A "carrier" or "network operator" that provides mobile telecommunication services.
SIMULINK
A programming language which provides interactive graphical environment along with the built in library for multi domain simulation.
Soft Handoff
The process, invisible to the user, of transferring a cellular phone conversation from one base station (cell tower) to another without interruption to the call. Soft handoffs do not require the original connection to be broken when transferring to an adjacent base station.
Spread Spectrum
A method of transmitting a radio frequency (RF) signal by "spreading" it over a broad range of frequencies. This facilitates reduced interference and increased capacity within a particular radio frequency band. CDMA technology is based on spread spectrum.
SS7
Signaling System 7. The protocol used in public-switched telephone systems for establishing calls and providing services such as 800 numbers, call forwarding, caller ID and number portability.
Subscriber
In wireless, a user of a mobile telecommunication service.
Synchronous
Communication transmissions that are timed by a clocking signal and occur with equal time intervals between them. An example is the constant transmission of time-sensitive data, such as real-time voice.
Sampling rate
Rate at which analog signal is sampled for digital conversion and vice versa.

TCP/IP
Transmission Control Protocol/Internet Protocol. A communications protocol that has become the de facto standard protocol for the Internet. "TCP" provides transport functions, ensuring that the total amount of data sent is correctly received. "IP" provides the routing mechanism, ensuring the information reaches the correct destination.
TDD
Time Division Duplexing. The application of time-division multiple access (TDMA) to separate inbound and outbound signals. Allows devices to transmit and receive on a single frequency at different time intervals.
TDMA
Time Division Multiple Access. A second-generation, digital wireless communication technology that increases the amount of data that can be delivered by dividing each cellular channel into time slots. Wireless standards that use TDMA technology include GSM, PDC and iDEN.
Thermal noise
Noise introduced in a communication system due to movement of electrons.
Turnaround time
The time required to transmit a message and receive its acknowledgement.
U
UMTS - a.k.a. WCDMA
Universal Mobile Telecommunications System. A third-generation (3G), CDMA-based wireless communication standard that offers enhanced voice and data capacity and higher data rates than previous, second generation wireless technologies.
Unicast
The transmission of content from a single source to a single receiver over a network.
Uplink
The connection from the end-user communications device to the network. In satellite communications, also refers to the connection from a terrestrial transmitter to a satellite.
In wireless communication it is connection from Subscriber to BS.
V
VSAT
Very-Small-Aperture Terminal.
Viterbi decoder

W
WAN
Wide Area Network. A geographically dispersed telecommunications network. A WAN may be privately owned or rented, but the term usually refers to a public network.
WCDMA
CDMA is a wideband spread-spectrum 3G mobile telecommunication air interface that utilizes code division multiple access (or CDMA the general multiplexing scheme, not to be confused with CDMA the standard). It provides simultaneous support for a wide range of services with different characteristics on a common 5MHz carrier
WEP
Wired Equivalency Privacy. An optional feature for Wi-Fi and 802.11b that offers privacy by using an encryption algorithm that scrambles data before any data is transmitted.
Wi-Fi
Short for "Wireless Fidelity" and another name for WLAN (wireless local area network). Allows a mobile user to connect to a local area network (LAN) through a wireless connection. Wi-Fi has been deployed in airports, universities, bookstores, coffee shops, office campuses and private residences. ( See Also: 802.11, Hot Spot, WLAN)
WiMAX
Wireless Interoperability for Microwave Access. A group of proposed wireless standards for high-throughput broadband connections over long distances. Applications include "last mile" broadband connections and hot spots. Trade name for a new family of IEEE 802.16 wireless standards. ( See Also: Broadband, Hot Spot, IEEE, Last Mile)
Wireless MAN (Metropolitan Area Network)
Wireless Metropolitan Area Network. Enables broadband network access with exterior antennas that communicate with base stations that are connected to core network. An alternative to fixed-line networks. Developed by the IEEE 802.16 Working Group. ( See Also: Broadband, IEEE
WLAN
Wireless Local Area Network. Where the movement is within a contained geographical area, you can provide mobility by implementing a wireless LAN and equipping your mobile device with a corresponding wireless adapter - a PC card variety that goes into a notebook, hand-held PDA, a Windows CE-compatible device or Palm Pilot organizer. Allows a mobile user to connect to a
local area network (LAN) through a wireless connection. WLANs have been deployed in airports, universities, bookstores, coffee shops, office campuses and private residences. ( See Also: 802.11, Hot Spot, Wi-Fi)
WPAN
Wireless Personal Area Network. These are wireless networks that can be installed in a small office or home within 5-15 metre distances. Two technologies being used for this purpose are IrDA which is based on line of sight requirement within two devices, usually a few feet apart. For more details on IrDA, please go to IrDA site. The second technology is Blue Tooth.
Blue tooth technology supports multipoint connection without line of sight requirement.
X
XML
extensible Markup Language. A computer language developed by the World Wide Web Consortium (W3C) designed to improve the functionality of the Internet by providing a more flexible way to share basic data, such as phone numbers or addresses. For example, XML may be used to share data between desktop computers and wireless devices.
Z
ZIF Direct Conversion
Zero Intermediate Frequency. A radio frequency architecture that eliminates the entire intermediate frequency section of the cellular phone, resulting in smaller-sized wireless devices. The basis of QUALCOMM's radioOne technology.

What is?

what is router ?
what is wimax?
what is lte?
what is 4G?
what is 3G?
what is an ip address?
what is mac address?
what is modulation?
what is FPGA?
what is DSP?
what is RF?
what is wireless ?
what is zigbee?
what is Bluetooth?
what is lightwave RF?
what is z-wave?
what is microcontroller?
what is GSM?
what is CDMA?
what is GPRS?
what is infrared?

What is Difference between

difference between FDM and OFDM
Difference between SC-FDMA and OFDM
Difference between SISO and MIMO
Difference between TDD and FDD
Difference between 802.11 standards viz.11-a,11-b,11-g and 11-n
OFDM vs OFDMA
CDMA vs GSM
Bluetooth vs zigbee
Fixed wimax vs mobile
wibro vs mobile wimax
Microcontroller vs microprocessor
FDM vs TDM
wimax vs lte
RF heterodyne versus homodyne receiver
white noise Vs. colored noise
FIR filter Vs. IIR filter
HSDPA vs HSUPA
SCPC Vs. MCPC
RS232 Vs. RS485
TD-SCDMA Vs. WCDMA Vs. CDMA2000
diff. BW DSSS and FHSS
FDMA Vs. TDMA Vs. CDMA
Diplexer versus Duplexer
R&S CMU200 Vs. Agilent 8960
rf isolator Vs. rf circulator
Sensitivity Vs. selectivity
hub Vs. switch
circuit switching Vs. packet switching
Difference between soft handover and softer handover

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