A
|
ACI
|
Adjacent channel interference
|
|
ADSL
|
Asymmetrical Digital Subscriber Line. A method to increase transmission speed in a copper cable. ADSL facilitates the division of capacity into a channel with higher speed to the subscriber, typically for video transmission and a channel with significantly lower speed in the other direction.
|
|
AFC
|
Automatic Frequency Control
|
|
AGC
|
Automatic Gain Control. Used to protect a device from optical overload while maintaining bandwidth and sensitivity performance
|
|
AGC Threshold
|
The level of input current at which the AGC circuit becomes active
|
|
AGC Time Constant
|
The amount of time it takes to achieve the required AGC level; also, the amount of time it takes to recover from AGC
|
|
AGL
|
Above Ground Level
|
|
AM
|
Amplitude Modulation
|
|
AMPS
|
Advanced Mobile Phone System. The original American standard specification for analog systems. Used primarily in North America, Latin America, Australia and parts of Russia and Asia
|
|
AN01
|
ANADIGICS GaAs HBT Version 1
|
|
AN04
|
ANADIGICS GaAs HBT Version 2
|
|
AN08
|
ANADIGICS GaAs HBT Version 3
|
|
Analog
|
Quantities or representations that are variable over a continuous range such as output of an amplitude-modulated, single-sideband transmitter. The amplitude as such a signal fluctuates over a continuous range from zero to the maximum, or peak, output
|
|
Analog (data transmission)
|
Pertaining to data in the form of continuously variable physical quantities
|
|
Analog Device
|
A device that operates with variables represented by continuously measured quantities such as voltages, resistances, rotations and pressures
|
|
Analog Signal
|
A signal that is solely dependent upon magnitude to express the information content
|
|
Analog-To-Digital Converter
|
A device that converts a signal whose input is information in the analog form and whose output is the same information in digital form
|
|
ANSI
|
American National Standards Institute
|
|
Antenna
|
A device for receiving or transmitting electromagnetic energy
|
|
Antenna Power Gain
|
The ratio of the effected radiated power to the RF actual power applied to the feed point. Usually expressed in decibels
|
|
APS
|
Antenna Positioning System
|
|
AR
|
Activity Radio
|
|
ASF
|
Application Service Positioning. A technology that facilitates downloading of software of the Internet instead of purchasing the program over the counter - against a fixed fee
|
|
ASIC
|
Application Specific Integrated Circuit
|
|
ASSP
|
Application Specific Standard Product
|
|
ATM
|
Asynchronous Transfer Mode. A technology for broadband transmission of voice, data and video transmission of telecom signals in large amounts. In addition to high capacity signal transmission, ATM provides considerable flexibility, since the individual subscriber is able to adapt the capacity of a switched connection to current requirements
|
|
ATSC
|
Advanced Television Systems Committee
|
|
Attenuation
|
The decrease in amplitude of a signal between any two points in a circuit. Usually expressed in decibels. Attenuation is the opposite of amplification
|
|
AWGN
|
Additive White Gaussian Noise
|
|
AXE
|
An open architecture, Ericsson's communications platform. A system for computer-controlled digital exchanges chat constitute the nodes in large public telecommunications networks. The basis for Ericsson's wireline and mobile systems
|
B
|
Background Noise
|
In an amplifier or other device that draws current, there is always some noise output in addition to the desired signal
|
|
BAN
|
Broadband Access Network
|
|
Bandwidth
|
The amount of frequency space occupied by a signal, and required for effective transfer of the information to be carried by that signal
|
|
Baud Rate
|
The measure of the speed of transmission of a digital code
|
|
BER
|
Bit Error Rate
|
|
Bias
|
A potential difference which is applied deliberately between two points for the purpose of controlling a circuit
|
|
Bit
|
A binary digit. The binary systems of numbers is often called base 2. The decimal system is base 10
|
|
Bit Rate
|
The rate of a binary-coded transmission which is the number of bits per second
|
|
Bluetooth
|
A radio technology developed by Ericsson and other companies built around a new chip that makes it possible to transmit signals over short distances between telephones, computers and other devices without the use of wires
|
|
Broadband Modulation
|
The transfer of information by a radio signal requires a certain minimum amount of spectrum space. This minimum depends on the rate at which this information is conveyed. Sometimes called wideband modulation
|
|
BiCMOS
|
Bipolar Complementary Metal Oxide Semiconductor
|
|
BPSK
|
Binary Phase Shift Keying
|
|
BTA
|
Basic Trading Area
|
C
|
Cable Communications
|
Any system of transferring information by wire
|
|
Cable Television
|
A supplement to conventional television. Signals are transmitted by cable and sometimes heterodyned, or converted to lower frequencies for more efficient transmission
|
|
CAP
|
Carrier Amplitude Phase Modulation
|
|
CATV
|
Community Antenna Television (cable television)
|
|
Carrier
|
An alternating-current wave of constant frequency, phase and amplitude. By varying the frequency, phase or amplitude of a carrier wave, information is transmitted
|
|
CDMA
|
Code Division Multiple Access. A technology for digital transmission of radio signals between, for example, a mobile telephone and a radio base station. In CDMA, a frequency is divided into a number of codes
|
|
CDPD
|
Cellular Digital Packet Data
|
|
Cellular
|
A wireless phone system that uses a grid of cells, each including transmitters, receivers, and antennas. Most of the world's cellular systems started with analog technology, although most operators are now migrating to digital to ease capacity restraints and offer new services
|
|
CEMA
|
Consumer Electronics Manufacturers Association
|
|
Channel
|
A particular band of frequencies to be occupied by one signal, or one 2-way conversation in a given mode
|
|
CMOS
|
Complementary Metal Oxide Semiconductor
|
|
CMRS
|
Commercial Mobile Radio Service
|
|
C/N
|
Carrier-to-Noise Ratio
|
|
Converter
|
Any device that converts frequency, voltage or current from one value to another
|
|
CTB
|
Composite Triple Beat
|
|
CT2
|
Cordless Telephone, 2nd Generation (digital)
|
|
CW
|
Continuous Wave
|
D
|
DAMPS
|
Digital Advanced Mobile Phone System. Earlier designation of American standard for digital mobile telephony used primarily in North America, Latin America, Australia and parts of Russia and Asia. Now known as TDMA.
|
|
DAVIC
|
Digital Audio Visual Council
|
|
DBM
|
Decibel reference to 1 milliwatt; 0 dBm equals one milliwatt
|
|
dBa
|
Adjusted decibels
|
|
DBS
|
Direct Broadcast Satellite
|
|
DC-To-AC Converter
|
A circuit that changes the voltages of a direct current power supply to alternating current supply
|
|
DC Transmission
|
When electric power is sent from one point to another as a direct current
|
|
DCS 1800
|
Variant of GSM at 1.8 GHz, used in Europe
|
|
DCS 1900
|
Variant of GSM at 1.9 GHz, for PCS applications
|
|
Decibel (dB)
|
A unit of measuring relative levels of current, voltage or power
|
|
DECT
|
Digital European Cordless Telephone
|
|
Demodulation
|
The extraction of the modulation or information from a radio-frequency current
|
|
Detector
|
The photodiode in optical receivers
|
|
Digital
|
A method of processing information through the use of electronic or optical pulses that represent the binary digits 0 and 1. Wireless digital technology enables clear sound, encrypted transmissions, and value-added text and data services. It is also more resistant to cloning fraud
|
|
Discrete Components
|
An electronic component such as a resistor capacitor inductor, or transistor that has been manufactured before its installation in the circuit
|
|
Dish Antenna
|
A high-gain antenna that is used for the transmission and reception of ultra-high-frequency and microwave signals
|
|
DMT
|
Discrete Multi-tone Modulation
|
|
Down Conversion
|
The heterodyning of an input signal with the output of local oscillator, resulting in an intermediate frequency that is lower than the incoming signal frequency
|
|
DQPSK
|
Differential quadrature phase shift keying
|
|
DSBSC
|
Double Sideband Suppressed Carrier
|
|
DSS
|
Digital Satellite System
|
|
DSSS
|
Direct Sequence Spread Spectrum
|
|
DTH
|
Direct-to-Home
|
|
DTV
|
Digital Television
|
|
DWDM
|
Dense Wave Division Multiplexing
|
E
|
EBU
|
European Broadcasting Union
|
|
EDGE
|
A technology that gives GSM and TDMA similar capacity to handle services for the third generation of mobile telephony. Developed to enable the transmission of large amounts of data at a high speed, 384 kilobits per second in mobile applications
|
|
EHF
|
Extremely High Frequency
|
|
EIRP
|
Effective Isotropic Radiated Power
|
|
EPG
|
Electronic Program Guide
|
|
EPOC
|
An operating system for mobile terminals, developed by Symbian (Ericsson joint-venture company including Matsushita, Motorola, Nokia and Psion)
|
|
ETACS
|
Extended Total Access Communication System
|
|
ETSI
|
European Telecommunications Standards Institute
|
|
EVM
|
Error Vector Magnitude
|
F
|
FCS
|
Fiber channel standard
|
|
F/D
|
Focal Distance-to-Diameter Ratio
|
|
FDDI
|
Fiber Distributed Digital Interface
|
|
FDM
|
Frequency Division Multiplex
|
|
FDMA
|
Frequency-Division Multiple Access
|
|
FEC
|
Forward Error Correction
|
|
FET
|
Field Effect Transistor
|
|
FEXT
|
Far-end Crosstalk
|
|
FHSS
|
Frequency hopping spread spectrum
|
|
Fiber Optics
|
Light beams transferred from one place to another by optical fiber or fibers
|
|
Filter
|
A passive or active frequency selective circuit designed to modify a signal or source of power
|
|
FM
|
Frequency Modulation
|
|
FNPRM
|
Further Notice of Proposed Rulemaking (from FCC)
|
|
Frequency
|
For any periodic disturbance, the frequency is the rate at which the cycle repeats. It is generally measured in cycles per second or Hertz (Hz). Rapid oscillation frequencies are specified in kilohertz (kHz), megahertz (MHz), gigahertz (GHz) and terahertz (THz). 1 kHz=1,000 Hz, 1 MHz=1,000 KHz; 1 GHz=1,000 MHz; and 1 THz=1,000 GHz
|
|
Front End
|
The first radio-frequency amplifier stage in a receiver. One of the most critical components of the receiver because the sensitivity of the front end dictates the sensitivity of the entire receiver
|
|
FQPSK
|
Filtered quadrature phase shift keying
|
|
FSK
|
Frequency Shift Keying
|
|
FSS
|
Fixed Satellite Service
|
|
FTTC
|
Fiber to the curb
|
|
FTTH
|
Fiber to the home
|
G
|
GaAs
|
Gallium Arsenide. A semiconductor which is used to fabricate high speed transistors.
|
|
Gain Control
|
An adjustable control that changes the gain of an amplifier
|
|
GFT
|
Generic Flow Control
|
|
GMSK
|
Gaussian minimum shift keying
|
|
GMT
|
Greenwich Mean Time
|
|
GPRS
|
General Packer Radio Service. A packer-linked technology that enables highspeed (115 kilobit per second) wireless Internet and other data communications
|
|
GPS
|
Global Positioning Satellite or Global Positioning System
|
|
GSM
|
Global System for Mobile Communication. Originally developed as a pan-European standard for digital mobile telephony, GSM has become the world's most widely used mobile system. It is used on the 900 MHz and 1800 MHz frequencies in Europe, Asia and Australia, and the 1900 MHz frequency in North America and Latin America
|
|
GSO
|
Geo-synchronous Orbit
|
|
G/T
|
Gain-over-Noise Temperature
|
|
Gummel-Poon
|
A type of electrical model describing the large signal behavior of bipolar transistors.
|
|
GUTS
|
Generic UDP Transport Service
|
H
|
HBT (Heterojunction Bipolar Transistor)
|
Transistor that offers higher RF power gain per stage and does not require a negative power supply
|
|
HDSL
|
High bit rate digital subscriber line
|
|
HDTV
|
High Definition Television
|
|
HEC
|
Header Error Control
|
|
Heterodyne
|
A process of the shifting of a signal of interest down to a frequency at which it may be processed more easily to extract information
|
|
HEMT (High Electron Mobility Transistor)
|
A transistor that yields the lowest noise figures in single FET devices
|
|
Hertz (Hz)
|
A unit of frequency equal to one complete cycle per second
|
|
HFC
|
High-band Fiber-optic Cable; Hybrid Fiber/Coax
|
|
HP
|
Horizontal Polarization
|
|
High Q
|
A filter circuit with a great deal of selectivity
|
|
HIPPI (High Performance Parallel Interface)
|
An 800 Mb/s interface to supercomputer networks
|
I
|
IEC
|
International Standards Group
|
|
IF (Intermediate Frequency)
|
Desired microwave signals are first heterodyned down to an IF frequency for ease of filtering, and then further heterodyned down to another IF or baseband where the information may be recovered
|
|
IMD
|
Intermodulation distortion - RF impairment where device non-idealities create new frequency components not in the original signal, including the common harmonic and two-tone distortion effects
|
|
Impedance
|
Resistance to alternating-current flow
|
|
IMSI
|
International Mobile Station Identity
|
|
IMT-2000
|
International Mobile Telecommunications. Standard adopted by the ITU for the third generation of mobile telephony. Actually a family of Five different specifications for the radio interface in this new system generation
|
|
Inductance
|
The ability of a device to store energy in the form of a magnetic field.
|
|
Inductor
|
An electronic component designed to provide a controlled amount of inductance
|
|
InGaP
|
Indium Gallium Phosphide. A semiconductor used to form the emitter region of a gallium arsenide heterojunction bipolar transistor.
|
|
Intermodulation
|
In a receiver, an unwanted signal sometimes interacts with the desired signal. The desired signal appears to be modulated by the undesired signal
|
|
IP
|
Internet Protocol. The Internet protocol defines how information travels between systems across the Internet
|
|
IP2
|
Second Order Intercept Point - Figure of merit for second-order (squaring) distortion of a component. Derived by artificially extrapolating a second-order response until it intercepts the fundamental input-output response
|
|
IP3
|
Third Order Intercept Point - Figure of merit for third-order (cubic) distortion of a component. Derived via artificially extrapolating a third-order response until it intercepts the fundamental input-output response
|
|
IPPV
|
Impulse pay-per-view
|
|
IRD
|
Integrated receiver-decoder
|
|
IS-136
|
A digital mobile telephony standard based on TDMA technology
|
|
IS-54
|
Interim Standard 54, for analog and digital cellular radio for all of North America
|
|
IS-95
|
A digital mobile telephony standard based on CDMA technology
|
|
ISDN
|
Integrated Service Digital Network
|
|
ISI
|
Intersymbol interference
|
|
ISL
|
Intersatellite link
|
|
ISM
|
Industrial Scientific & Medical (unlicensed frequency bands 915 MHz, 2.4 & 5.725 GHz)
|
|
ISP
|
Internet service provider. A company specializing in offering end-users access to the Internet. As a rule does not have own communications network but functions as a link between the user and the net operator
|
|
ITFS
|
Instructional television fixed service
|
|
ITU
|
International Telecommunications Union. A United Nations agency that deals with telecommunications issues
|
|
IXC
|
Interexchange Carrier
|
J
|
JDC
|
Japan Digital Cellular, 900 to 1500 MHz
|
K
|
Kilohertz (kHz)
|
A unit of frequency equal to 1,000 hertz, or 1,000 cycles per second
|
L
|
LAN
|
Local Area Network. A small data network covering a limited area, such as within a building or group of buildings
|
|
Laser
|
A device that generates coherent electromagnetic radiation in, or near, the visible part of the spectrum
|
|
LEC
|
Local Exchange Carrier
|
|
LMDS
|
Local multipoint distribution service. American standard for high-speed transmission of voice and data using so-called Pmp (Point-toMultipoint) solutions. Used to provide wireless broadband traffic to small and medium-size companies or in apartment buildings
|
|
LNA
|
Low-noise amplifier - RF gain device designed specifically for very low imposition of additional noise power. Used to amplify very low signals without contributing significant SNR degradation
|
|
LNB
|
Low noise block downconverter
|
|
LO
|
Low Oscillator - Refers to the frequency conversion CW source used in the RF mixing process
|
|
LOS
|
Line of sight
|
M
|
MAC
|
Medium access control
|
|
MATV
|
Master antenna television
|
|
MBU
|
Multiple business unit
|
|
MCNS
|
Multimedia Cable Network Systems
|
|
MCS
|
Multipoint communications systems
|
|
MDS
|
Multipoint distribution service
|
|
MDU
|
Multiple dwelling unit
|
|
MESFET
|
Metal Semiconductor Field Effect Transistor
|
|
Microwaves
|
That part of the electromagnetic spectrum at which the wavelength falls between about 30 centimeters and 1 millimeter. Microwave frequencies range from 1 GHz to 300 GHz. Microwaves are very short electromagnetic radio waves but have a long wavelength than infrared energy
|
|
Microwave Oscillator
|
A device used to generate a microwave signal. It consists of two parts: a resonator to control the frequency of the microwave signal and an active device to generate the power
|
|
MIM
|
Metal-Insulator-Metal. A method of making capacitors in integrated circuits.
|
|
Mixer
|
A nonlinear circuit that produces an output at the sum and difference frequencies of an applied fixed or variable oscillator called the LO, and the RF input signal of interest. (see Heterodyne)
|
|
MMDS
|
Multipoint Microwave Distribution System (also known as Wireless Cable)
|
|
MMIC (Microwave Monolithic Integrated Circuit)
|
The process by which active devices such as MESFETs and diodes, and passive devices including inductors, capacitors, resistors, and interconnects are fabricated on the same GaAs chip
|
|
MOCVD
|
Metalorganic Chemical Vapor Deposition. A method for growing epitaxial films using metalorganic precursors for the Group III elements.
|
|
Modulation
|
When some characteristics of an electromagnetic wave are deliberately changed or manipulated for the purpose of transmitting information (see Amplitude Modulation, Frequency Modulation and Phase Modulation)
|
|
MONET
|
Multiwavelength Optical Networking
|
|
MPEG
|
Moving Picture Experts Group of the International Standards Organization (set video compression standard)
|
|
MSA
|
Metropolitan Statistical Area
|
|
MSC
|
Mobile Switching Center
|
|
MSO
|
Multi-system operator
|
|
MTA
|
Major Trading Area
|
|
MTBF
|
Mean time between failures
|
|
MTTF
|
Median Time To Failure. Used in reliability studies to denote the time at which half the population under study has failed.
|
|
MVPD
|
Multichannel video programming distributor
|
N
|
NADC
|
North American Digital Cellular or North American Digital Cordless
|
|
NAMPS
|
Narrow Band Advanced Mobile Phone Service
|
|
NEXT
|
Near-end crosstalk
|
|
NMT
|
Nordic Mobile Telephone
|
|
Noise Figure
|
A measure of the ability of an amplifier to increase the strength of a signal while adding the minimum possible self-generated noise. It is mathematically equal to ten times the log of the input S/N ratio to the output S/N ratio
|
|
NTSC
|
National Television Standards Committee (which created U.S. color TV standard)
|
O
|
OC-192
|
Refers to Optical Communications family of products designed for 10GBps optical communications systems.
|
|
OFS
|
Operational fixed service
|
|
OHM
|
The standard unit of resistance, reactance and impedance. A resistance of 1 ohm will conduct 1 ampere of current when a voltage of 1 volt is place across it
|
|
Optical Overload
|
A condition of high input current that cause pulse width distortion at the output of the TIA
|
|
OQPSK
|
Offset quadrature phase shift keying
|
P
|
PACA
|
Priority Access and Channel Assignment
|
|
PACS (TDMA)
|
Personal Access Communication System
|
|
PAL
|
Phase alternate line (European color TV standard)
|
|
Passive Component
|
A component that requires no external source of power for its functionality
|
|
PBX
|
Private Branch Exchange. An exchange system used in companies and organizations to handle internal and external calls.
|
|
PCIA
|
Personal Communications Industry Association
|
|
PCMCIA
|
Personal Computer Memory Card International Association
|
|
PCN
|
Personal Communications Network
|
|
PCS
|
Personal Communications Services. Collective term for American mobile telephone services in the 1900 MHz frequency band
|
|
PCS/PCN
|
Personal Communications System/Network
|
|
PDA
|
Personal Digital Assistant
|
|
PDC
|
Personal Digital Cellular. A Japanese standard for digital mobile telephony in the 800 MHz and 1500 MHz bands
|
|
PDU
|
Protocol data unit
|
|
Phase
|
A relative quantity describing the time relationship between or among waves having identical frequency. The complete wave cycle is divided into 360 equal parts, called degrees of phase
|
|
Phase Distortion
|
When the output of an amplifier fluctuates in phase, even though the input does not, the circuit introduces phase distortion into the signal
|
|
Phase Modulation (PM)
|
When the information is impressed on a radio frequency signal by varying its phase angle
|
|
pHEMT
|
p = pseudomorphic H=high E=electron M=mobility T= transistor
|
|
Photodiode
|
A semiconductor device that converts light to electrical current
|
|
PHP
|
Personal Handy Phone (Japan)
|
|
PHS
|
Personal Handy Phone System
|
|
Photoresistor
|
A device that exhibits a variable resistance, depending on the amount of light that strikes it
|
|
PoP
|
Point of presence
|
|
POTS
|
Plain old telephone service
|
|
Power Amplifier
|
An amplifier that delivers a certain amount of alternating-current power to a load. Used in audio-frequency and radio-frequency applications
|
|
Power Gain
|
An increase in signal power between one point and another. Used as a specification for power amplifiers
|
|
Power Transistor
|
A semiconductor transistor designed for power-amplifier applications at audio and radio frequencies
|
|
PPV
|
Pay-per-view
|
|
PSD
|
Power spectral density
|
|
PSTN
|
Public Switched Telephone Network
|
|
PTI
|
Payload type indicator
|
Q
|
QAM
|
Quadrature amplitude modulation
|
|
Q Factor
|
For a capacitor, inductor or tuned circuit, the Q factor, or Q, is a figure of merit. The higher the Q, the lower the loss and the more efficient the component
|
|
QPSK
|
Quadrature phase shift key
|
R
|
Receiver
|
Any circuit that intercepts a signal, processes the signal, and converts it to a form useful to a person. The signal may be in any form such as electric currents in a wire, radio waves, modulated light, or ultrasound. The receiver converts signals into audio information, video information, or both
|
|
Resistance
|
The opposition that a substance offers to the flow of electric current
|
|
Resistor
|
An electronic component that is deliberately designed to have a specific amount of resistance
|
|
Response Time
|
The length of time between the occurrence of an event and the response of an instrument or circuit to that event
|
|
RF (Radio Frequency)
|
An electromagnetic disturbance is a radio frequency if the wavelength falls within the range of 30 km to 1 mm. This represents a frequency rang of 10 kHz to 3000 GHz. The input signal from the antenna is an RF signal
|
|
RFI
|
Radio frequency interference
|
|
RMA
|
Random multiple access
|
|
Roaming
|
A method that enables subscribers of one wireless operator to use their handset in another carrier's service area. Customers cannot roam on a network unless their home carrier and the visited operator have a roaming agreement and a user has compatible equipment
|
|
Router
|
A data switch that handles connections between different networks. A router identifies the addresses on data passing through the switch, determines which route the transmission should take and collects data in so-called packets that are then sent to their destinations
|
|
RSA
|
Rural Service Area
|
|
RSH
|
Response station hub
|
|
RX
|
Receiver - General abbreviation used in many situations, referring to items such as electrical data receivers, optical receivers, radio receivers and digital communication demodulators
|
S
|
SAW
|
Surface acoustic wave (filter) - Filter or oscillator technology characterized by its reliance on acoustic energy and electrical/acoustic transductors used to take advantage of impressive bandpass filter shape factors that are difficult to achieve with more traditional filter technologies
|
|
SCI
|
Scaleable coherent interface
|
|
SCPC
|
Single channel per carrier
|
|
SDH
|
Synchronous digital hierarchy
|
|
SIM
|
Subscriber Identity Module
|
|
SLM
|
Signal level meter
|
|
SMATV
|
Satellite master antenna television
|
|
SMR (Specialized Mobile Radio)
|
A communications service at 800 MHz and 900 MHz. Traditionally used to provide dispatch operations over analog networks, SMR now includes digital networks offering integrated dispatch messaging and cellular communications
|
|
SMS
|
Short messaging service
|
|
S/N
|
Signal-to-noise ratio
|
|
SNR (Signal-To-Noise Ratio)
|
The sensitivity of a communications receiver is generally specified in terms of the audio signal-to-noise ratio that results from an input signal of a certain number of microvolts
|
|
SOHO
|
Small office, home office
|
|
SONET
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Synchronous optical network - North American high speed baseband digital transport standard specifying incrementally increasing data stream rates for movement across digital optical links
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SSPA
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Solid-state power amplifier
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STA
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Synchronous transport module
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Switch
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A mechanical or electric device that is used to deliberately interrupt, or alter the path of the current through the circuit
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T
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TACS
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Total Access Communication System
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TDM
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Time Division Multiplexing
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TDMA
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Time Division Multiple Access. A technology for digital transmission of radio signals between, for example, a mobile phone and a radio base station. In TDMA, the frequency band is split into a number of channels that are stacked into short time units so that several calls can share a single channel without interfering with one another. TDMA is also the name of a digital technology based on the IS -136 standard. TDMA is the current designation for what was formerly known as D-AMPS. See also IS-136 and D-AMPS
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3GPP (Third-generation Partnership Project)
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A global cooperative project in which in which standardization bodies in Europe, Japan, South Korea and the United States as founders are coordinating WCDMA issues. See also WCDMA
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Threshold
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The minimum level at which a signal of any kind can be detected, either by the human senses or by using any electronic instrumentation
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TQFP
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Thin Quad Flat Pack
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TI
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Terrestrial interference
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TIA (Transimpedance Amplifier)
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A device used to convert input currents to output voltages
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Transceiver
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A combination of a transmitter and a receiver having a common frequency control and usually enclosed in a single package. Extensively used in two-way radio communications at all frequencies
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Transducer
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A device that converts one form of energy or disturbance into another. Transducers convert AC or DC into sound, radio waves or other forms
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Transimpedance
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The transfer function of a TIA; the output voltage divided by the input current
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Transistor
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A semiconductor device consisting of three or four layers used for switching or amplification at frequencies ranging from direct-current to ultra-high
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TSAR
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Teleservice Segmentation And Reassembly
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TVRO
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Television receive-only
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TX
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Transmitter - General abbreviation for items such as a digital communication modulator ICs, microwave point-to-point transmit modules, satellite downlink equipment and optical transmit components
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U
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UHF (Ultra-High Frequency)
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That range of the radio spectrum band that extends from 300 MHz to 3 GHz
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UMTS
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Universal Mobile Telecommunications System. The name of the third-generation mobile phone standard in Europe, standardized by ETSI
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U-NII
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Unlicensed National Information Infrastructure spectrum at 5.8-GHz
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Upconverter
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A device used to add a lower frequency to a microwave frequency
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V
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VBIC
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Vertical Bipolar Inter-Company. A type of electrical model describing the large signal behavior of bipolar transistors. The VBIC model is an improvement over the Gummel Poon model because it includes temperature dependence of device parameters.
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VCO
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Voltage controlled oscillator - Frequency generation component whose output frequency can be varied by changing the voltage to a control port on the device
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VDSL
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Very high rate digital subscriber line
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VoIP
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Voice over Internet Protocol. A technology for transmitting ordinary telephone calls over the Internet using packetlinked routes. Also called IP telephony
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VP
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Vertical polarization
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VPI
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Virtual path indicator
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VSAT
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Very small aperture terminal
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VSWR
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Voltage standing wave ratio - Measure of the RF interface quality between adjacent RF circuits that require adequate impedance matching for proper transfer of electrical energy at high frequencies
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VTO
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Voltage tuned oscillator
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W
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WAN
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Wide Area Network
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WAP
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Wireless Application Protocol. A free, unlicensed protocol for wireless communications that makes it possible to create advanced telecommunications services and to access Internet pages from a mobile telephone. WAP is the de facto standard that is supported by a large number of suppliers.
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WCA
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Wireless Cable Association International
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WCDMA
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Wideband Code Division Multiple Access. A technology for wideband digital radio communications of Internet, multimedia, video and other capacity-demanding applications. WCDMA, developed by Ericsson and others, has been selected for the third generation of mobile telephone systems in Europe, Japan and the United States. The technology is also the principal alternative being discussed in other parts of the world, notably Asia
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WCS
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Wireless communications service
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WDM
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Wavelength Division Multiplexing. A new technology that uses optical signals on different wavelengths to increase the capacity of fiber optic networks in order to handle a number of services simultaneously
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W-LAN
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Wireless-Local Area Network. A wireless version of the LAN. Provides access to the LAN even when the user is not in the office
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WLL
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Wireless Local Loop
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