Wireless Glossary

DailyWireless Glossary of Terms

    First Generation cellular: analog cell phones.
    1xRTT CDMA
    — Specifically, 1xRTT (otherwise known as 3G 1x) represents one times radio transmission technology with 1.25 MHz channels. This technology supports peak data speeds up to 144 kbps, and up to a doubling of voice capacity.
    Enhanced data rate Second Generation


    Second Generation cellular – digital cellular including TDMA, CDMA, and GSM systems. Most 2G digital phones are voice only phones, but some offer limited data capability.
    Third Generation Wireless technology, expected to reach maturity between the years 2003 and 2005, will be characterized by support for very high-speed data transmission rates. This will open up a host of new possibilities for both fixed and mobile wireless, such as real-time multimedia applications.

    The 3rd Generation Partnership Project (3GPP) is a collaboration agreement that was established in December 1998. The collaboration agreement brings together a number of telecommunications standards bodies that are known as “Organizational Partners”. The current Organizational Partners are ARIB, CCSA, ETSI, T1, TTA, and TTC. The original scope of 3GPP was to produce globally applicable Technical Specifications and Technical Reports for a 3rd Generation Mobile System based on evolved GSM core networks and the radio access technologies that they support (i.e., Universal Terrestrial Radio Access (UTRA) both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) modes). The scope was subsequently amended to include the maintenance and development of the Global System for Mobile communication (GSM) Technical Specifications and Technical Reports including evolved radio access technologies (e.g. General Packet Radio Service (GPRS) and Enhanced Data rates for GSM Evolution (EDGE)).
    3GPP2 was born out of the International Telecommunication Union’s (ITU) International Mobile Telecommunications “IMT-2000” initiative, covering high speed, broadband, and Internet Protocol (IP)-based mobile systems featuring network-to-network interconnection, feature/service transparency, global roaming and seamless services independent of location. IMT-2000 is intended to bring high-quality mobile multimedia telecommunications to a worldwide mass market by achieving the goals of increasing the speed and ease of wireless communications, responding to the problems faced by the increased demand to pass data via telecommunications, and providing “anytime, anywhere” services.
    The concept of a “Partnership Project” was pioneered by the European Telecommunications Standards Institute (ETSI) early in 1998 with the proposal to create a Third Generation Partnership Project (3GPP) focusing on Global System for Mobile (GSM) technology. Although discussions did take place between ETSI and the ANSI-41 community with a view to consolidating collaboration efforts for all ITU “family members,” in the end it was deemed appropriate that a parallel Partnership Project be established – “3GPP2,” which, like its sister project 3GPP, embodies the benefits of a collaborative effort (timely delivery of output, speedy working methods), while at the same time benefiting from recognition as a specifications-developing body, providing easier access of the outputs into the ITU after transposition of the specifications in a Standards Development Organization (SDO) into a standard and submittal via the national process, as applicable, into the ITU.

    — Another name for the W-CDMA 3G standard.
    Stands for 3G-service provider. It is mobile operators that have 3G licenses to provide 3G services to customers.
    IEEE standards for wireless LANs with specs for 1-2, 11 and 24 Mbps with access points typically covering 50-100 meters each.


    Advanced Forward Link Trilateration. This method of location is unique to CDMA (code-division multiple access) networks, since they are inherently synchronous in their operation. It measures the phase delay between signals sent to a pair of base stations and then compares this to the same data taken from another pair. Data of three base stations can be used to positively locate a MS. Accuracy: 50-200m.
    Accelerated Test
    A test designed to shorten the test time by increasing the frequency or duration of environmental stress that would be expected to occur during normal application.

    Access Point
    A stationary device that acts as a base station for wireless LAN users. Unlike a network interface card that connects to a mobile device, the access point connects directly to a wired network.

    Adaptive (Smart) Antenna
    An antenna system having circuit elements associated with its radiating elements such that one or more of the antenna properties are controlled by the received signal.
    Adaptive Frequency Hopping
    A method whereby a Bluetooth radio would first check that a band was clear before it attempted a transmission. This would allow Bluetooth radios to better peacefully exist with other radios such as 802.11b.

    Additions. The number of subscribers a carrier adds in a given period (monthly, quarterly, and/or annually). They are typically measured in terms of net adds (number of additional subscribers, minus number that have churned) or gross adds (total additions for that period).

    Automatic Gain Control. There are two electronic ways to control the recording of something – Manual Gain Control or Automatic Gain Control. AGC is an electronic circuit in tape recorders, speakerphones and voice devices that is used to maintain volume. AGC is not always a good idea since it will attempt to produce constant volume level, that is, it will try to equalize all sounds – the volume of your voice, and, when you stop talking, the circuit static and/or general room noise which you do not want amplified. Manual Gain Control means there is a record volume control.


    Aggregation is the process of collecting charges for multiple transactions and combining them on a single bill. Charges are typically aggregated when the cost of processing the individual transaction exceeds the profit that would be realized from that transaction.

    Air Interface
    In mobile phones, the ‘air interface’ denotes the specification of the radio transmission between base station and mobile phone. It defines the frequency use (frequencies), the bandwidth of the individual radio channels (channels), the encoding methods used (W-CDMA, TD-CDMA, cdma2000) and other quantities used by the radio technology
    Advanced Mobile Phone System is a somewhat ironic name for the original cellular system authorized in the North America. It uses an analog FM radio link and it is very easy to eavesdrop on it. AMPS is particularly inefficient in use of spectrum compared to any of the digital standards. Generally AMPS still has the best coverage of any of the standards (solely due to its ten year head start on build-out), but that’s about the only thing it has going for it. Sound quality is generally worse than any of the digital standards. Used in North America, Latin America, Australia and parts of Russia and Asia.

    AMR (Adaptive Multi-Rate)
    AMR is a speech coder standard introduced by the 3rd Generation Partnership Project (3GPP), a partnership project of various standards organizations, developed to preserve high speech quality under a wide range of transmission conditions. A codec offering a wide range of data rates. The philosophy behind AMR is to lower the codec rate as the interference increases and thus enabling more error correction to be applied. The AMR codec is also used to harmonize the codec standards amongst different cellular systems.
    AMR (Automatic Meter Reading)
    The automated reading of utility meters, generally power utility meters. AMR can be made of a wired or wireless technology, including cellular and LEOs (Low Earth Orbiting satellites).
    The technology which until recently was the norm for mobile phones, for example, 1G. It gives lower call quality and a major security risk.
    American National Standards Institute. A standards setting, non-government organization founded in 1918, which develops and publishes standards for transmission codes, protocols and high level languages for voluntary use in the United States. http://www.ansi.org


    Formerly known as IS-41 or TIA/EIA-41, this is a wireless intersystem operation standard/protocol used for switch-to-switch and network-to-network coordination with IS-136 and certain 3G standards. The core network for cdma2000 is based on the ANSI-41 standard. For 3G, ANSI-41 and GSM MAP networks will be interconnected through a signaling converter to realize global roaming.
    A metallic device used in the transmission and reception of electromagnetic waves. An antenna is a passive or an active device, which permits transmission.


    Antenna Diversity
    The use of two or more antennas to improve signal quality. In most designs, the baseband processor automatically selects the antenna that is providing the best quality signal.

    Antenna Power Gain
    The ratio of the antenna’s maximum radiation intensity in a stated direction to the maximum radiation intensity of a reference antenna (dipole, isotropic antenna) with identical power applied to both.


    Angle of Arrival. This method uses multiple antennas at a BTS to determine the incident angle of an arriving signal from a MS. The information of two BTSs allow to calculate the position of the MS. This technique is very sensitive for multipath signals, that have to be accounted for. Installing and aligning antenna arrays on base stations can be a sensitive and costly process. Accuracy: 100-200m.
    Application Protocol Data Unit


    An Access Point Name (APN) is assigned to each external network interface to the GGSM. Information about which of these external networks an individual subscriber is allowed access is contained in the HLR as an APN list in their profile.

    Application consists of a set of security mechanisms, files, data and protocols (excluding transmission protocols).


    Application protocol
    Set of procedures required by the application.


    Association of Radio Industries and Businesses – Japan. The objectives of ARIB are to conduct investigation, research & development and consultation of utilization of radio waves from the view of developing radio industries, and to promote realization and popularization of new radio systems in the field of telecommunications and broadcasting. Thus, ARIB aims at promotion to public welfare. http://www.arib.or.jp


    Average Revenue Per Unit or, Average Revenue Per User (Unit and User are both common usage). This refers to the amount of gross revenue a carrier can expect, on average, from its customers. Typically computed on monthly, quarterly, and annual basis.

    American Standard Code for Information Interchange – ASCII is now universally used as the prime means of converting characters to digital format for storage with or communication between computers and peripherals. The code assigns a sequence of 8 1’s and 0’s, or bits, to each of 256 characters commonly needed to accurately convey text-based information.


    Application-Specific Integrated Circuit – A silicon chip that is custom-designed for a specific purpose, at least that’s the pure definition. In actuality, the term is misleading because many ASICs are designed to perform multiple, generalized tasks. From the manufacturers point of view, a microprocessor is an ASIC, though they can and are used for widely disparate purposes in the field. Manufacturers use ASICs to consolidate many chips into a single package, thereby reducing system board size and power consumption.


    Active Server Pages – Microsoft’s Server-side scripting technology to make interactive web pages. Based on VBScript.


    Asynchronous Transmission
    A mode in which the sending and receiving serial hosts know where a character begins and ends because each byte is framed with additional bits, called a start bit and a stop bit. A start bit indicates the beginning of a new character; it is always 0 (zero). A stop bit marks the end of the character. It appears after the parity bit, if one is in use.
    Asynchronous Transfer Mode – Very high-speed data transmission technology. ATM is a high bandwidth, low-delay, connection-oriented, packet-like switching and multiplexing technique. Usable capacity is segmented into 53-byte fixed-size cells, consisting of header and information fields, allocated to services on demand. The term “asynchronous” applies, as each cell is presented to the network on a “start-stop” basis – in other words, asynchronously.


    The loss in power of electromagnetic signals between transmission and reception points.
    Horizontal direction expressed as the angular distance between the direction of a fixed point (as the observer’s heading) and the direction of the object.


    A Body Area Network means wireless communication between various components attached to the body, such as data spectacles, earphones, microphones and sensors for medical applications and for work and leisure.
    Bandwidth of a communications channel is a measure of the range of frequencies over which the carrier signal is allowed to vary. Generally a communications channel is defined by its lowest and highest frequency, and channel bandwidth is computed as the difference between the two as measured in Hertz, kHz or MHz. Since bandwidth of a channel is directly proportional to the amount of data that can be transmitted over it per unit time, channel bandwidth is sometimes measured as a data rate rather a frequency difference.
    Technical term for the capacity of a transmission channel. Because capacity, or even maximum speed, is generally dependent on the frequency range available, the ‘bandwidth’ (i.e., the width of a frequency band) usually has the same meaning as the maximum transmission speed available to a subscriber.


    Base station
    In a cellular communication system, a base station could be considered a central mode of transmission and reception for the network. Currently, this station includes an ominidirectional antenna or several sectoral antennas.
    Broadcast Control Channel

    The angle of signal coverage provided by an antenna. Beamwidth typically decreases as antenna gain increases.
    Bearer independent protocol
    Mechanism by which the Terminal provides the RUIM with access to the data bearers supported by the Terminal and the network.
    Border Gateway – The border gateway or BG provides interconnection between GPRS networks across inter-PLMN backbones.

    1. The smallest or basic unit in the digital representation of information, a bit can be thought of a binary digit taking the value of 1 or 0.
    2. Within the context of CDMA is distinct from chip and refers to a payload binary digit. Each bit is represented by many chips. Bits contain information and are subject to the laws of Information Theory.


    The speed at which bits are transmitted over the physical layer, also called signaling rate. This is quite different than throughput, which is an end measure of a network’s speed.

    A radio technology built around a new chip that makes it possible to transmit signals over short distances between computers and handheld devices without the use of wires.
    A global initiative by Ericsson, IBM, Intel, Nokia and Toshiba to set a standard for cable-free connectivity between mobile phones, mobile PCs, handheld computers and other peripherals. It will use short-range radio links in the 2.gGHZ Instrumentation Scientific and Medical (ISM) “free band”.


    1) Capacity constraint that may limit traffic carried on the network during peak load conditions.
    2) In the US, part of the local loop, which is monopolized, is known as a bottleneck, because only one carrier provides the service. Thus it is a regulatory term and affects how prices are regulated.


    Bits per second – meaning data transmission speed, the number of pieces of information transmitted per second.


    The interwoven outer conductive layer of coaxial cable made up of several bare conductors that come together to form a solid or nearly solid layer or shield. Braid is rated by percentage of coverage and by pixels per inch. Pixels per-inch indicates the number of crossings of the braid in one inch of cable.

    Braid Coverage
    Braid coverage is measured in percentage and reflects the density of the outer (shield) area of a piece of coaxial cable. Generally the higher the percentage, the better the cable grade.


    Binary Runtime Environment for Wireless
    A term used to describe a channel or communications line offering a bandwidth > 2Mb/s. (Synonymous with Wideband)


    The simultaneous transmission of data or voice to a number of stations.
    Base Station Controller/Base Station System/Base Transceiver Station – The heart of a cellular mobile phone system is a network of distributed transmitting/receiving radios in fixed locations called base transceiver stations (BTS). A base station controller or BSC is used to control groups of BTS’, provide mobility management for mobile stations, anchor airlink protocols and provide connection to an MCS or mobile switching center. The composite collection of one or more BTS and the associated BSC will form a BSS or Base Station Subsystem.


    A Byte is a sequence of bits (usual 8), which represents a single character, such as a letter of the alphabet, a decimal digit or a punctuation mark.

    Cable Loss
    A numeric value reflecting the amount or signal loss from one point of length of cable to another. This is measured in microvolts in two-way radio products and in decibels (dB) loss in cellular phone equipment.

    Call Drop Rate
    A dropped call rate out of completed sending calls (a sending call drop rate) or out of completed receiving calls (a receiving call drop rate).
    Capacitor/Capacitance Fed
    A capacitor is a storage device for electrical energy. A capacitor, has two metal plates separated by an insulator, in a glass mount antenna the insulator is the glass itself. A capacitor has two functions, first it allows alternating current to pass through it, and secondly it blocks direct current from crossing from one plate to the other. A capacitance fed glass mount antenna allows alternating current energy to pass through the glass to the external radiating element. Received radio signals follow the reverse process to reach the radio receiver.

    A licensed company (network operator) may market any number of communication services for voice and data. Carriers offer their services to both end-customers (private or business) and other carriers. In the latter case, the service simply consists of transport capacity for long-distance traffic. For example, local/regional network operators will buy transport capacity from carriers that operate on a global basis.
    Carrier Signal
    A signal transmitted at a pre-determined frequency to act as a “carrier” for voice or data. The carrier signal is modulated by voice or data input so as to “carry” the information to its destination where the modulation process is reversed to recover the original information.

    China Communications Standards Association – A standards agency in China. http://www.ccsa.org.cn/


    CDMA Development Group – The purpose of the CDG is to lead the rapid evolution and deployment of CDMA-based systems, based on open standards and encompassing all core architectures, to meet the needs of markets around the world in an emerging, information-intensive environment. CDG is three-stage process. All CDMA devices must pass all three stages. Stage 1: RF Parametric Testing, Stage 2: Interoperability Test (network infrastructure compatibility) and Stage 3: Field testing (typically done by the network operator). http://www.cdg.org/


    Code Division Multiple Access – A technology for digital transmission of radio signals between, for example, a mobile telephone and a base station. The system uses the same frequency to allow multiple conversations. Each conversation is cut into snippets and then remodulated in reassembled in the other end.


    Common name for IMT-2000 CDMA Multi-Carrier.


    CDMA2000 1X
    The first step in the evolution to 3G is cdma2000 1X, which improves packet data transmission capabilities and speeds in the network, and also boosts voice capacity by nearly two times over today’s CDMA capacities. Speed of up to 144kpps.
    CDMA2000 1xEV-DO
    (Evolution Data-Only). CDMA2000 1XEV represents the second step in the evolution of CDMA2000. Commercially launched in 2001, offers data speeds of up to 2.4 Mbps on a separate 1.25 MHz carrier.


    CDMA2000 1xEV-DV
    (Evolution Data-Voice). CDMA2000 1XEV represents the second step in the evolution of CDMA2000. Recently approved by ITU as a 3G technology, will provide data and voice together on a single 1.25 MHz channel, with data rates of up to 4.8 Mbps.
    CDMA2000 3X
    3G technologies, which offers voice and data on a 5MHz carrier (or 3 times [3X] the 1.25 MHz carrier). Full 3G version of CDMA2000. Technology is similar to CDMA2000 1x, but the peak data rate is 2Mbps.


    CDMAOne (IS-95)
    CDMAOne is a digital mobile phone standard based on the CDMA principle, which is used in North America, Korea and Japan. CDMAOne uses frequency ranges around 800MHz and 1900MHz. For migration to third generation mobile telephony, CDMAOne networks can be upgraded to the cdma2000 broadband standard.
    Cellular Digital Packet Data is a data communications technology that uses Internet standard protocols to enable packet data services to be overlaid on an existing cellular network.


    Originally CDR stood for ‘call detail record’, a call transaction record created by the MSC to track the network resources used by subscribers in making and receiving circuit switched calls, so that billing systems could compute charges based on resource usage (e.g. minutes on the air etc.). Today the term more generally applies to any transaction, traffic or resources usage records created by various other network components which may subsequently be used for billing purposes and is sometimes called a ‘charging’ detail record. So, for example, packet traffic information will appear in CDRs created by GPRS components such as the SGSN and GGSN.

    Communauté Européenne

    CE Mark
    The CE Marking is the manufacturer’s declaration, showing compliance with all applicable directives. For most products sold in the EU, the use of the CE Marking and a Declaration of Conformity are mandatory.
    With the exception of some high-risk products, most products can be self- assessed by the manufacturer to meet the Essential Requirements. While the CE Marking does permit a product’s access to the EU, it is not an approval mark, certification or quality mark; nor is it intended to be a marketing tool. CE is a “Marking” that is only a declaration of the supplier’s own responsibility.

    The basic geographical unit of a cellular communications system. Service coverage of a given area is based on an interlocking network of cells, each with a radio base station (transmitter/receiver) at its center. The size of each cell is determined by the terrain and forecasted number of users.
    Cell phone
    An American term for mobile phone.
    Cell Site
    An alternative name for a base station transceiver or its site.

    Cell Switching
    Feature that enables a caller to move from one location to another without losing the connection. The cellular system is designed to switch calls to a new call without a noticeable drop in the connection. While not noticeable in voice communications, the 300 milliseconds required for cell switching can cause problems in data transmission.


    Cell Site (BTS) Identification. Most basic wireless location technology. Latitude/longitude of BTS is taken as the MS location. Available on all networks. Relative accuracy depends on size of cell. Accuracy: 100-3000m.
    Circuit-switched voice telephone communications via cellular radio channels. The service area is divided into many cells and in each there is a base station handling the communications in that particular cell.
    Center Conductor
    A solid or stranded electrical conductor generally composed of copper and located at the center of the coaxial cable.

    Center Fed
    Transmission line connection at the electrical center of an antenna radiator.

    Charging Gateway – The charging gateway or CG collects, validates and consolidates CDRs from other network components such as the SGSN and GGSN. It may then format the results for processing by the network billing system.

    An individual UMTS radio channel is defined in the IMT 2000 standard as having a bandwidth of 5 MHz. This means that an individual UMTS radio channel, for example, ranges from 1900 to 1905 MHz. How many radio channels a UMTS provider can make available to customers depends on which frequency spectrum has been won in the auctioning of UMTS mobile phone frequencies. Each radio channel can transport more than one connection. So that more than one subscriber can use the same channel, multiple access methods such as W-CDMA (FDD), TD-CDMA (TDD) or cdma2000 are used for 3G networks. It nevertheless depends on the service profile of the connection how many connections per channel can be managed at the same time. It is also true that in the planning of the radio network, the effect of cellular respiration for CDMA should be considered.
    In the context of CDMA is distinct from bit and refers to binary digits transmitted over the RF link. The chip rate in IS-95 is 1.2288 MHz (thus allowing adequate guard bands to permit the carriers to be spaced 1.25 MHz apart). Each bit is represented by many chips, and if a majority of the chips get through then the bit can be reconstructed properly. The number of chips representing each bit varies depending on the bit rate. When using an 8K Vocoder (such as EVRC) there are 128 chips for each bit. Chips as such don’t contain data because both the sender and receiver know the spreading pattern used to create them from a bit, and as such are not directly subject to the laws of Information Theory. Though there are many phones simultaneously using a single frequency to transmit full chiprate, which means that the channel is not saturated unless the bitrate approaches the bandwidth of the carrier.


    A group of IC chips that are designed to work together and generally used and priced as a set.

    Compact Hyper Text Markup Language (basis for iMode).

    Circuit Switched Cellular (CSC)
    Circuit Switched Cellular, good for large data transfers, offers wide coverage. Also see Circuit Switched Data.

    Circuit Switched Data (CSD)
    Data communication over a dedicated channel or circuit assigned on a per call basis. CSD calls are often metered and priced by the minute like voice calls.

    Circuit Switching
    A method of communicating in which a dedicated communications path established between two devices through one or more intermediate switching nodes. Unlike packet switching, digital data are sent as a continuous stream of bits. Bandwidth is guaranteed, and delay is essentially limited to propagation time. The telephone system uses circuit switching.
    Caller Line Identification. Service that allows a customer to see the number of the caller before answering the call.
    Coaxial Cable
    Cable consisting of a single copper conductor in the center surrounded by a plastic layer for insulation and a braided metal outer shield. Coax is used to transfer radio frequency energy from the transmitter to the atenna.


    (pronounced CO-deck, short for compressor/decompressor) refers to a device inside the phone (and at the cell system) which takes digitized voice and compresses it prior to transmission to the cell, and which takes compressed voice received from the cell and decompresses it prior to playing it out the speaker of the phone. Codec algorithms are extremely sophisticated and are designed specifically around the characteristics of human voices and human ears. There are three in common use in IS-95, called “8K”, “13K” and EVRC. GSM and IS-136 have their own codec standards.

    Coding gain
    In CDMA refers to the ability to use digital techniques and redundancy inherent in the chip sequence to reproduce the bit sequence without requiring much absolute power on the RF. Generally speaking, the more coding gain, the less absolute power is needed to get the signal through. CDMA uses very sophisticated error correction methods (such as the Viterbi FEC Encoder/Decoder) to increase the coding gain.

    Collinear Array
    A system of two antenna radiators arranged in a line and connected end to end so as to generate a directed field pattern.

    A metal body such as tubing, rod, or wire that permits current to travel continuously along its length.

    Conference call
    Allows you to speak to more than one person at the same time. This can be extremely useful for remote business meetings. To use this service, it must be supported by your network and by your phone. You may also have to add this service to your subscription.
    Control Channel
    A channel used for transmission of digital control information from a base station to a cellular phone (forward control channel) or from a cellular phone to a base station (reverse control channel).

    Core Network
    The switching part of the UMTS network. It provides call control and performs mobility and high-level security functions such as location updating and authentication. Core network includes a radio access network, terminals and applications.


    Core router
    Core routers are switching computers used on the main connection links (backbone) of a network. These switching computers are particularly powerful, and specialize in the transfer of huge data volumes over the information highway.
    A wire or group of wires mounted close to ground, but insulated from ground, to form a low-impedance, high-capacitance path the ground. Used at medium frequencies (MF) and high frequencies (HF) to provide an RF ground for an antenna. (Also see ground plane.)

    Referring to on-glass antennas, a coupler is the two-piece interface between the coaxial cable on the inside of the glass and the radiator on the outside of the vehicle. It is designed to efficiently couple RF energy through the glass. The formulation of the glass and glass thickness normally has a substantial effect on coupler performance.
    The geographical reach of a mobile phone network or system.


    Customer Relationship Management. A vast way of approach to customers in an attempt to realize their living style in every field of life and eventually to influence them to change their life style toward a benefitable direction through the company initiating ceaseless communication of indirect, implicative and inspiring suggestion so that the company may attract new customers and bind existing customers steady with the company.
    Circuit Switched Data: is the traditional technology used for the exchange of data. A circuit connection is made that is exclusively reserved for the individual’s use. Payment is then made in accordance with the duration of the connection. This can be inefficient, for example when connecting to the internet using WAP, as more time is spent reading the information than is spent exchanging data, however you continue to pay when you are reading. For corporate e-mail services however, applications have been developed where the user works “off line” and then only connects to the server to download and receive e-mails.
    Carrier Sense Multiple Access – A MAC method of listening before transmitting (collision avoidance) and listening while transmitting (collision detection). For a wired network, such as Ethernet, collision detection is employed and packets are retransmitted should a collision be detected while transmitting. For wireless networks, this type of collision detection is usually not possible since the strength of a radio’s own transmissions would mask all other signals on the air. So for wireless networks, collision avoidance is employed.


    Cellular Telecommunications & Internet Association. CTIA is the international organization that represents all sectors of wireless communications-cellular, personal communication services and enhanced specialized mobile radio. We serve the interests of service providers, manufacturers, wireless data and Internet companies and other contributors to the wireless universe.
    CTIA is the voice of the wireless industry – representing its members in a constant dialogue with policy makers in the Executive Branch, in the Federal Communications Commission, and in Congress, CTIA’s industry committees provide leadership in the area of taxation, roaming, safety, regulations, fraud and technology. www.ctia.org


    Clear to Send


    Current Loop
    A point of current maxima (antinode) on an antenna.

    Current Node
    A point of current minima on an antenna.


    D-AMPS has been renamed TDMA (Time Division Multiple Access). TDMA is a digital mobile phone network that operates in the US, Latin America, New Zealand, parts of Russia and Asia Pacific. Ericsson’s TDMA mobile phones also work on AMPS networks.
    dB (decibel)
    Logarithmic way to express a value. Usually the signal strength (transmitted and received power) is expressed in dBm (the reference is 1 mW = 0 dBm). A difference between two values in dBm is without unit, in dB.


    dBd (Decibels Dipole)
    A measurement of signal gain used in radio antenna design. Specifically dBd refers to signal gain in a dipole radiator, which is a basic antenna consisting of two rods with their ends slightly separated. In the most basic form, the dipole is radiator comprises two horizontal rods.
    dBi (Decibels Isotropic)
    A measurement of signal gain used in radio antenna design. Specifically dBi refers to signal gain of an isotropic radiator, which is a transmitting antenna that radiates a signal equally well in all directions.


    A precise measure of power based upon the decibel scale, but referenced to the milliwatt: i.e. 1 dBm = .001 Watt. DBM is often used to describe absolute power level where the point of reference is 1 milliwatt. In high power applications the DBW is often used with a reference of 1 Watt.


    The ration of the power to one Watt expressed in decibels.


    Dc ground
    An antenna, which is a dead short to a DC current, and has a shunt fed design. To RF it is not seen as a short.
    Data Carrier Detect


    Data Circuit Terminating Equipment

    European 1800 MHz GSM band.


    This refers to the act of decoding encrypted information so that it can be understood.

    Digital Enhanced Cordless Telecommunications – A standard for cordless telephony.


    Refers to the process of establishing a connection via the switched telephone network.

    The newest form of wireless communications that takes all voice transmissions and converts them to computer language (zeros and ones, or “binary” language) and then reconstructs them into the original voice format at the other end. More secure than its original sibling, analog, and also relatively impervious to static or fading signals.
    An antenna that is split at the exact center for connection to a feed line usually a half wavelength long. Also called a “doublet”.

    Directional Antenna
    An antenna having the property of radiating or receiving electromagnetic waves more effectively in some directions than others.
    The theoretical characteristic of an antenna to concentrate power in only one direction, whether transmitting or receiving.
    DMU (Dynamic Mobile IP Key Update)
    The Dynamic Mobile IP Key Update procedure is a secure and efficient mechanism for distributing and updating Mobile IP (MIP) cryptographic keys in cdma2000(R) networks (including High Rate Packet Data, which is often referred to as 1xEV-DO). Because the Dynamic Mobile IP Key Update (DMU) procedure occurs at the IP layer directly between the MIP MN and RADIUS or DIAMETER AAA Server, DMU may be used to securely bootstrap the MN-AAA key (and other cryptographic keys) in MIP networks using any Radio Access Network technology.

    DNS (Domain Name System)
    The domain name system (DNS) provides the means whereby Internet domain names are located and translated into Internet Protocol addresses.


    DNS Server
    A DNS server holds translation tables linking domain names and APNs to IP addresses. It supplies the information to routers and other Internet elements on request.

    Document Type Definition (DTD)
    A DTD defines the names and contents of all elements that are permissible in a certain document. A DTD is used to specify XML document structure.

    An Internet domain consists of a set of network addresses organized into levels for purposes of identification, routing and information delivery. The top level generally identifies a type of organization (e.g. “.com” for commercial, “.org” for non-commercial, and “.net” for communications network) or a geographic location such as a country. The second level identifies a unique place within the top-level grouping and is equivalent to a unique address on the Internet.

    Most data-communication connections are bi-directional. The direction toward the remote user is referred to as the “downlink”. The direction away from the remote user is referred as the “uplink”. Technical term for data transmission in the direction from the network, the provider or the Internet provider to the subscriber. (The return channel is known as the uplink.)

    Differential Quadrature Phase-Shift Keying – An Improvement to QPSK, this compression technique transmits only the differences between values of the phase of the sin wave, rather than the full absolute value. QPSK makes use of two carrier signals, separated by 90-degrees.

    Driven Element
    A radiator element of an antenna system to which the transmission line is connected.

    Dropped Call
    A wireless call that is unintentionally disconnected due to a system problem, lack of channel availability or dead spot in coverage.


    Direct Spread Frequency Division Duplex. European asynchronous W-CDMA FDD mode.
    Direct Sequence/Spread Wideband Code Division Multiple Access. A 3G-radio interface for UMTS, also known as UTRA FDD or WCDMA-DS, and adopted as the IMT-DS 3G standard
    Digital Signal Processor – A digital signal processor is a specialized computer chip designed to perform speedy and complex operations on digitized waveforms Useful in processing sound (like voice calls) and video.

    Data Terminal Equipment

    Data Terminal Ready

    Dual Band
    Dual band phones are capable of using two different frequencies of the same technologies. For example, a TDMA or CDMA phone that can use either the 800 or 1900 MHz band. There are also Triple Band phones in the GSM market that support 900, 1800, and 1900 MHz. Dual band phones allow callers to access different frequencies in the same or different geographic regions, essentially giving their phone a wider coverage area.

    Dual Mode
    Dual mode phones are phones that support more than one technology. Typically, this is either CDMA and AMPS or TDMA and AMPS, but other dual mode phones are starting to appear on the market, such as GSM and TDMA.


    Digital Video Broadcasting is harmonized digital TV that covers all media (satellite, cable and terrestrial). It supports Internet services at speed up to 6 Mbps and can be used on mobile devices.
    Enhanced GPRS, another term for EDGE.

    Enhanced Observed Time Difference. This method includes new technology in the handset to assist in locating the unit in a network. Handsets in an E-OTD system are set up to support positioning in a network where base stations are asynchronous. One implementation of this method has the handset reporting back measured times from three base stations to be combined with timing data from various points in the network (LMUs) in order to determine the MS location. Accuracy: 50-200m.
    E-Plane and H-Plane
    Antenna measurements in general and radiation patterns in particular must be performed with polarization in mind. Since polarization is defined as having the same orientation as an antenna’s electric field vector, it is common practice to refer to measurements aligned with either the electric vector ( E-plane) or magnetic vector (H-plane).
    (pronounced Eee-See over Eye-Not) in CDMA refers to the portion of the RF signal which is usable. It’s the difference between the signal strength and the noise floor.

    Enhanced Data rates for GSM Evolution. EDGE has been developed for those networks that didn’t but a UMTS license and while it promises only about a third of the bandwidth, most UMTS services will also have a form using EDGE. Speed of up to 184kbps will be possible.


    The ratio of useful output power determined in antenna systems by losses in the system including in nearby objects. (Also see VSWR.)

    Enhanced Full Rate

    Effective Isotropic Radiated Power – A measure of the radiated power from a transmitter entering the atmosphere.

    Electrically Small Antenna
    Some antennas (such as various low profile antennas, some base loaded whips and often rubber duckie portable antennas) are physically considerably smaller than either a 1/2 or 1/4 wavelength antenna. The challenge with electrically small antennas is to maintain radiating efficiency. A greater challenge is to design an antenna with adequate bandwidth. Careful design using high quality materials often overcome these obstacles.
    Embedded Antennas
    Antennas directly integrated into a system such as an access point, a terminal or a handset. In most cases, this antenna is matched to the system and cannot be used in other applications without modification.
    Electromagnetic Conformity


    Refers to the act of altering data to make it unreadable unless you know how to decrypt it.

    Enhanced Messaging Service (EMS)
    Messaging comprising simple pictures, sounds, animations, and modified text.


    A new operating system for mobile multimedia terminals developed by Symbian.
    European Radio Messaging System.


    Effective RaWireless Glossary, Acronyms and Abbreviationsdiated Power.

    Error Detection & Correction
    Refers to various techniques used to detect and correct errors that may be introduced when digital data is copied, moved or transmitted to another device. Detection and correction technologies generally require that the data be expanded to include additional information, which can noticeably impact the rate at which the effective information is delivered.


    ESMR (Enhanced Specialized Mobile Radio)
    an enhancement to SMR technology, allowing two-way radio service with the capability to provide wireless voice telephone service to compete against cellular. It uses TDMA technology to put six voice conversations into one 25KHz UHF radio channel in the 806-821MHz band. ESMR can be deployed on a cellular basis, and supports hand-off, like cellular radios. ESMR was developed by Nextel and Geotek. ESMR will support low-speed data, as well as voice.
    (Electronic Serial Number) Is a unique number assigned to the phone by the phone manufacturer. No two phones will ever have the same ESN.


    ETACS (Extended TACS)
    The cellular technology used in the United Kingdom and other countries. It is developed from the U.S. AMPS technology. See AMPS, TACS and NAMPS.


    European Telecomunications Standards Institute, is the European counterpart to ANSI, the American Standards Institute. ETSI’s task is to pave the way for telecomunivation integration in the European community as part of the single European market plan. See www.etsi.org


    (Enhanced Variable Rate Codec) is a new codec being rolled out as this is written (2/2000) for IS-95 and J-STD-008 systems. It uses 8Kbps bandwidth but sounds nearly as good as the standard 13K codec. Because of this, when the majority of phones can use EVRC the cell systems will have more capacity without having to deploy more equipment. This should yield better service.

    An extranet is an external extension of a company’s intranet that allows limited, external access to defined portions of the intranet.


    Final Assembly Code

    Frequency Division Duplex is the first variation of W-CDMA to be standardized and will appear commercially for the first time in Japan, mid 2001


    Frequency division multiple access. Division of the frequency band allocated for wireless cellular telephone communication into 30 channels, each of which can carry a voice conversation or, with digital service, carry digital data. FDMA is a basic technology used in the analogue AMPS the most widely-installed cellular phone system installed in North America. With FDMA, each channel can be assigned to only one user at a time. The D-AMPS also uses FDMA but adds TDMA to get three channels for each FDMA channel, tripling the number of calls that can be handled on a channel. It is also applicable in fixed networks.
    Forward Error Correction or FEC is a technique used in data communications to in aid detecting and correcting transmission errors. FEC methods require that redundant information be added to help compensate for possible losses and is most often used in situations where it is impractical to retransmit information damaged in transit.


    Fiber Optic Cable
    A cable, consisting of a center glass core surrounded by layers of plastic that transmits data using light rather than electricity. It has the ability to carry more information over much longer distance.
    Field Strength
    An absolute measure in one direction of the electromagnetic wave field generated by an antenna at some distance away from the antenna.

    Field Tunable
    Antennas identified as Field Tunable are shipped with a cut chart the installer uses to select a desired operating frequency by tuning the antenna to resonance. Cut charts should be used as guidelines and are adequately accurate for many applications. However, Radiall/Larsen recommends using appropriate RF measurement devices whenever possible for more accurate tuning.
    A firewall provides a security layer between one network and another. A firewall is situated between the GGSN and any external packet data networks connected to it. This provides a measure of protection for the GPRS network and its subscribers from hackers, spammers or other unauthorized use.

    Fixed Access
    A terminal access to the network that users wired technology.
    Freedom of Mobile Multimedia Access, DoCoMo’s brand name for 3G services, based on the W-CDMA format. Introductory FOMA services for a limited number of users is to begin at the end of May, with full commercial services due in October.
    Forward link
    Refers to the radio link from the cell to the phone.

    Full Rate

    Is the name of a CDMA digital voice packet duration. Frames are 20 milliseconds long. IS-95 transmits 50 frames per second, with each frame containing sufficient information to reproduce 20 milliseconds of sound. It should be pointed out that it may not require the whole 20 milliseconds to transmit the frame. The IS-95 codecs can generate “half-rate”, “quarter-rate” and “eighth-rate” packets if the sound in that 20 milliseconds is sufficiently simple to require fewer bits to represent. A half rate packet only requires 10 milliseconds to transmit. An eighth rate packet only requires 2.5 milliseconds to transmit.


    Rate of signal oscillation in hertz, meaning the number of times the wave form repeats itself in second (measured in Hertz (Hz) where one Hz is one cycle per second). The frequencies band assigned to GSM is 900-1800 MHz. For 3G the band assigned are between 1885-2025 MHz and 2110-2200 MHz.
    Frequency Band
    A frequency band is a continuous range of frequencies over which a signal waveform or carrier is allowed to vary.

    Frequency Modulation (FM)
    A technique for adding information to a carrier signal (e.g. a radio wave) whereby variations in the input are reflected by varying the frequency of the transmitted signal. This is the basis for FM radio.

    Frequency Reuse
    The ability to use the same frequencies repeatedly across a cellular system, made possible by the basic design approach for cellular. Since each cell is designed to use radio frequencies only within its boundaries, the same frequencies can be reused in other cells not far away with little potential for interference. The reuse of frequencies is what enables a cellular system to handle a huge number of calls with a limited number of channels.

    Frequency Spectrum
    Spectrum available for communication. Regulatory agencies monitor the occupancy of the radio spectrum and allocate to individual/group users, enabling a large number of services to operate within specific limits of interference.
    Full Type Approval

    Full Duplex
    Refers to a communication system or equipment capable of transmission simultaneously in two directions.


    Fixed Wireless Access is an emerging terrestrial system for radio access in the 4GHz and 25GHz bands. It is the use of wireless technology to replace copper to connect subscribers to the telephone network and Internet.
    A data traffic detail record created by the GGSN, which may subsequently be used for billing purposes.

    Ga, Gb, Gf, Gi, Gn, Gp, Gr, Gs
    Each of these designates an interface between a particular pair of components in a GPRS network. For example, Gb denotes the interface between the SGSN and a Base Station Subsystem, or BSS. Such interfaces general comprise hardware, software, protocols and control mechanisms required to move GPRS traffic from point in the system to another.

    Gain is the practical value of the directivity of an antenna. It takes into account the efficiency of the complete structure.
    Usually a computer that acts as a protocol translator or which controls communications across logical boundaries within a network or between networks.

    GCF (GSM Certification Forum)
    GCF is a partnership between network operators and terminal manufacturers that has been formed with the objective of establishing an independent program to ensure global interoperability of GSM terminals. Although the GCF scheme currently only applies to GSM 900 and GSM 1800 terminals, it is not restricted to GSM and has been designed to migrate to 3G and whatever comes after that.

    GGSN (Gateway GPRS Support Node)
    The GGSN provides the interconnection between the GPRS network and external packet data networks, much as the MSC interconnects a GSM voice services to the PSTN. Viewed externally, its primary function is that of a router.


    GHz (Gigahertz)
    A frequency measurement. One hertz equals one cycle per second. GHz = One Billion hertz.

    Gigahertz (GHz)
    One billion cycles per second.
    Global Mobile Personal Communications via Satellite. A group of proposals for advanced satellite based systems to extend the coverage afforded by terrestrial cellular systems and aiming to provide worldwide coverage of mobile services. Three projects called Iridium, Global star and ICO came out from it.
    GMSK (Gaussian Minimum Shift Keying)
    The radio signal modulation technique used in GSM based communications today.

    Gound Plane
    A man made system of conductors placed below an antenna to serve as an earth ground.
    General Purpose Input/Output


    General Packet Radio Service refers to a new, packet-based wireless communication service that promises data rates from 56 up to 114 Kbps and continuous connection to the Internet for wireless phone and mobile computer users. The higher data rates as well as the “always connected” mode of operation will open the door to many new, non-voice applications and services. GPRS was designed as an enhancement to GSM communications, but will probably be adapted and adopted by at least some network operators using technologies other than GSM.

    GPS (Global Position System)
    Based on US defense satellite system, enables tracking of individuals. This technology may prove helpful when navigating a car in the city, or help emergency rescue-team to locate the person in need of help. CDMA cell systems use fixed GPS receivers to determine the time very precisely. This is needed to synchronize the long code and short code in the infrastructure.

    Ground Plane
    A system of conductors placed beneath an elevated or mobile antenna to serve as an earth ground. Note that at very high frequencies the human body can act as a ground plane. (Also see counterpoise.)

    The Global System for Mobile Communications Service, or GSM, is the most widely adopted, digital cellular technology in use today. GSM uses time and frequency division techniques (TDMA and FDMA) to optimize the call carrying capacity of a wireless network. In addition to voice services GSM also provides a number of carefully standardized and broadly supported capabilities such as Short Message Service (SMS), circuit switched data (CSD) and General Packet Radio Services (GPRS). Used on the 900 MHz and 1800 MHz frequencies in Europe, Asia and Australia, and the MHz 1900 frequency in America.

    GSM-AMR is an Adaptive Multi Rate (AMR) speech coder standard introduced by the 3rd Generation Partnership Project (3GPP), which is a partnership project of various standards organizations, for compressing the toll quality speech (8000 samples/second). This speech coder is mainly used for speech compression in the 3rd generation mobile telephony.
    This coder has eight basic bit rates, 12.2, 10.2, 7.95, 7.40, 6.70, 5.90, 5.15 and 4.75 Kbps. This coder uses the principle of Algebraic Code Excited Linear Prediction (ACELP) for all bit rates. Besides, there are two types of Voice Activity Detection and Comfort Noise Generation (VAD/CNG) algorithms.
    The coder works on a frame of 160 speech samples (20 msec), and no look ahead is required. So the algorithmic delay for the coder is 20 msec.

    GSN (GPRS Support Node)
    A general term referring the principal components of a GPRS network, e.g. GGSN and SGSN components.

    GTP (GPRS Tunneling Protocol)
    IP packets traveling across the GPRS backbone (the data highway within the boundaries of a particular GPRS network) are enclosed in an additional protocol “wrapper” that contains information linking the destination IP address with the IMSI or mobile subscriber identifier (e.g. MIN). This is invisible in the Internet world but essential inside the GPRS network where dynamic IP assignments are used. The technique of adding a wrapper with additional routing information is called ‘tunneling’, and the particular protocol used for this purpose is the GTP or GPRS Tunneling Protocol.


    See E-Plane.
    The process of maintaining a radio link between a cellular radiotelephone and the cellular system. The handoff occurs when the radiotelephone moves out of range of one cell site and comes into range of another, relying on Received Signal Strength Indication (RSSI) to determine when handoff is necessary.


    Another term for cellular phones. Mobile phone, cell phone, and handset are used interchangeably.

    Handheld Markup Language. Invented by phone.com, predecessor to WML.


    Information added by the protocol in front of the payload in the packet for its own use (addresses, packet type, sequence number, CRC…). Each protocol adds a different header, so in a typical TCP/IP packet as transmitted, we have a MAC header, an IP header and a TCP header, followed by the payload.

    Hertz or Hz
    Hertz is a unit of measurement for frequency of a cyclical waveform or repeating signal, which is equal to one cycle per second.


    A fixed wireless broadband access network.


    An Home Location Register is database that resides within a cellular network to hold current details about a subscriber, the equipment in use, the service(s) required, the user’s identification encryption code, and the users “Home” cell, and what network the subscriber was last known to be using.


    Half Rate

    (High Speed Circuit Switched Data). A circuit-linked technology for higher transmission speed by combining several GSM channels at the same time. This may allow speeds up to 58 bps, far faster than original GSM (9.6bps). For upload HSCSD is limited to half the speed. This technology is the predecessor of GPRS, which may deliver up to 115kbs.


    A modified TDMA technology used by Motorola and run by Nextel Communications, Southern LINC, and a handful of other carriers around the world. iDEN phones run on a different frequency than other cellular services and are therefore incompatible with them.


    Idle handoff
    In CDMA is when the phone moves from one sector or cell to another while not in a call. If it moves from one zone to another it will register. If the new cell or sector is part of the same zone, it does not need to register.

    (Pronounced I-Triple E) Institute of Electronic and Electrical Engineers. The IEEE is a non-profit, technical professional association that promotes electronic ideas and standards both in the US and Worldwide. www.ieee.org


    Internet Engineering Task Force. The IETF is a large open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet. It is open to any interested individual. The actual technical work of the IETF is done in its working groups, which are organized by topic into several areas. Much of the work is handled via mailing list. The Internet standards-related documents are published as RFC (Request For Comments).
    IF (Intermediate Frequency)
    To increase sensitivity and selectivity, super heterodyne radio receivers first convert the input frequency to a fixed frequency and then apply the internal processing to that fixed frequency. The intermediate frequency is the frequency used for this internal signal processing.

    IMEI (International Mobile Equipment Identity)
    A unique identification number associated with each GSM phone. In effect, a serial number that aids in tracking a particular device and is useful in fraud prevention. The IMEI is assigned by the manufacturer.

    Wireless Internet service from NTT DoCoMo, based on Compact HTML. Japanese network NTT DoCoMo has had a great deal of success with iMode, with the main advantage over WAP being that it is packet-switched network. Thus, it actually runs at the same speed of connection as WAP, but because the network is packet switched, it works considerably faster- and in color.
    The Ohmic value of an antenna feed point, matching section or transmission line at a radio frequency. An impedance may contain a reactance as well as a resistance component.
    IMSI (International Mobile Subscriber Identity)
    A unique identification number associated with a particular GSM subscriber. In effect a serial number that is essential to tracking the profile and location of a particular GSM subscriber, as well as making billing and service provisioning possible. It is assigned by the network operator, is carried in the SIM. More than one ‘phone number’ or MSISDN may be associated with the same IMSI.

    International Mobile Telecommunications 2000. The ITU initiative for a service that will provide radio access to the global telecommunications infrastructure, through both satellite and terrestrial systems, serving fixed and mobile users in public and private networks. In other words, third-generation services.


    Industry Canada (IC)
    Regulatory body in Canada. Purpose: Verification of RF emissions – not causing harmful interference to other wireless users, electrical equipment and people. For operation in the Canada, the integration (or end device) is required to meet appropriate regulatory requirements Industry Canada Radio Standards Specification RSS-129, RSS-133 and RSS-102, as well as Interference-Causing Equipment Standard ICES-003. www.ic.gc.ca
    The Internet is a data communication network that ties together computer networks in many parts of the world and that makes it possible for users to tap into information made available at tens of thousands of participating computer sites. Many new standards and technologies have been developed to make sharing information over the Internet easier. For example, mark-up languages like HTML sets standards for how shared information is to be laid out and, while browsers provide interpret the “mark -ups” and display the retrieved information on the user’s computer screen or printer.

    IP (Internet Protocol)
    The Internet Protocol (IP) is the method or protocol by which data is sent from one computer to another on the Internet.

    IP Address
    The unique digital identifier of a device communicating over the Internet or other data network using similar technology. Today’s addresses consist of a 32-bit string of 1’s and 0’s and are analogous to postal addresses.

    Internet Protocol, Version 6, IPv6 was developed by the IEFT as a version of the IP protocol. It was accepted as an Internet standard in December 1995 because of work on IPng (next generation). This version is a further development of Version 4 (IPv4). The main enhancements are as follows: Extended addressing options, simplified header format, improved support for options and extensions, new facilities for defining the level of service, and improved security procedures. IPv6 has extended the address space from 32 bits to 128 bits, so that a significantly higher number of addressable Internet nodes can be addressed, several hierarchy levels are possible, and the auto configuration of addresses is simplified. The IPv6 header consists of a 4-bit version field for the IP version, a priority field of the same length for level-of-service attributes, and a 24-bit flow-label field, which is used by the data source to identify data packets that require special handling with a specific level of service.
    TDMA Interim Standard 136. (See TDMA).

    Inter-network connection protocol for connecting systems based on both analog and digital US standards.


    First-generation TDMA in 1991.
    A standard which describes a cell system which uses a CDMA link and operates at 800 MHz. Sometimes the term is also used to describe 1900 MHz CDMA, though that properly is covered by J-STD-008. The two standards are similar and as time has gone on they have been migrating towards each other and have become more similar.

    An Internet Service Provider, or ISP, provides Internet access to people or corporations, serving as an entry point to the worldwide network. ISPs normally provide several means of access to their customers, including dial-up modem, DSL and ISDN.

    International Telecommunication Union. The ITU is the most important telecommunications standards setting body in the world. In actual fact, it has no power to set standards. But if its members agree on a standard, it effectively becomes a world standard. The ITU presently consists of three major sectors that were established in 1992: 1) the Radio communication Sector (ITU-R), the telecommunication Development Sector (ITU-D), and the Telecommunication Standardization Sector (ITU-T). The ITU took over the work formerly done by the CCITT (Comite Consultatif Internationale Consultative Committee). The scope of the ITU’s work is much broader than just telegraphy and telephony. It also includes IP voice, telematics, data, new services, systems and networks.

    ITU-T SSG IMT-2000
    International Telecommunication Union-Terminal Special Study Group IMT-2000. This body is part of the International Telecommunications Union and offers a long-term vision related to the evolution of IMT-2000 systems and other systems over the next ten years.
    IVR (Interactive Voice Response)
    A software application, typically used in conjunction with corporate telephony hardware, which recognizes spoken commands. Typically used for helping callers navigate corporate directories and phonebooks or for other types of menu-driven services. Usually limited in the number of commands that can be recognized.

    The Interworking Function, sometimes called an Interworking Working Unit (IWU), is a wireless network component that enables communications between a computing device transmitting data over a wireless network and one normally accessible via dial-up modem over the public telephone network. The IWF provides a data bridge between a digital wireless network and the public telephone system.


    An Interworking Unit, sometimes called an Interworking Working Function (IWF), is a wireless network component that enables communications between a computing device transmitting data over a wireless network and one normally accessible via dial-up modem over the public telephone network. The IWU provides a data bridge between a digital wireless network and the public telephone system.

    A standard that describes a cell system that uses a CDMA link and operates at 1900 MHz. It is similar to, but not identical to, IS-95.

    Java 2 Microedition, a technology developed by Sun MicroSystems. For more information, browse to http://java.sun.com/j2me/

    KB or Kb
    Kilobyte is a term denoting 1024 bytes, roughly equal to 8 kilobits.


    Kilobits per second – A speed measurement for the transmitting of data (see bps).

    A unit of measurement for frequency equal to 1000 Hertz.

    A Local Area Network, or LAN, consists of a group of inter-connected computer terminals or nodes, often co-located and managed from a single point as a single network, such as an organization or business might deploy for sharing and managing information internally.

    Usually refers to the OSI specification dividing any communicating system into 7 layers, each having a different functionality. Layer 1 is the physical layer (radio), layer 2 is the link layer, and IP could be assimilated as layer 3 (network layer). TCP is considered layer 4, the transport layer. For more information on the OSI 7-Layer Model browse our AIRSOURCE Knowledgebase at https://support.airdesk.net > solution #375
    LBS (Location-Based Services)
    Services or applications that center around a user’s location in a mobile environment. Location-based services utilize location-sensitive technology, such as Global Positioning Satellite (GPS) or network-based solutions, to deliver services or applications to a wireless device such as a mobile phone. These services can include finder applications that let mobile phone users locate friends or family, businesses or landmarks. They can also deliver maps, directions, or traffic reports.
    LIG (Lawful Interception Gateway)
    The lawful interception gateways provides a mechanism whereby designated security or law enforcement agencies can intercept GPRS traffic, much as voice “wiretap” facilities are provided in mobile networks. Today. Legal authority to use this mechanism as well as safeguards to protect privacy will vary from country to country.

    Lightning Protector
    A device designed to divert large surges of current such as a lightning strike from reaching the RF equipment. There are many types of lightning protectors including Quarter Wave Stub and Gas Discharge Tubes.


    Link layer
    This is the part of the protocol managing the direct delivery between two devices on a specific physical layer (coaxial bus, point to point link, radio). This includes packetization and addressing. Most of this is implemented in the MAC in a WLAN.

    LMDS (Local Multi-point Distribution Services)
    LMDS broadband services operate over the 28-31 GHz bands in the US and provide high data rates, but only over a relatively short distance of three miles.

    Location Measurement Unit
    Location-based Applications
    Location-based applications allow end users to find community services near their location such as hotels, restaurants, pharmacies, banks, gas stations, and many other neighborhood services. These applications are effective in both consumer and business markets.
    Location-based Service
    A service that tracks a cellular phone user’s location within the mobile network and provides a variety of additional services: E911 service automatically notifies an emergency center of a user’s location when he/she is in an urgent situation. Location Based Billing Service provides a discount rate when calling and receiving at a specific area. Tracking service grasps and manages the location of a person and an object. Location Based Information Service provides local information on the area near subscribers. All these services are made possible by a wide range of technology; GPS + Cell based (location) Tracking, Measuring Signal Attenuation (between a subscriber’s hardware and a base station), Server Aided GPS System, Assisted GPS Tracking made of DSP Software based device and TOA (Time Of Arrival)/TDOA (Time Difference Of Arrival) Tracking. Server Aided GPS System was developed by SnapTrack, tested and verified at CDMA, GSM networks and is now under commercialization.
    Long code
    In CDMA is a chip sequence that is 240 chips long, which repeats every 41.4 days. Its primary purpose is to assist in spreading the signal, to make spread spectrum work more efficiently. The Long code used on the reverse link is usually modified using the phone’s ESN when in a call.

    MAC (Medium Access Control)
    This is the part of the radio device managing the protocol and the usage of the link. The MAC decides when to transmit and when to receive, creates the packets headers and filters the received packet.


    Metropolitan Area Network. A regional computer or communication network spanning the area covered by an average to large city.
    MB or Mb (Megabyte)
    Megabit is a term denoting approximately one million bits. There is some argument as to whether a megabit should signify one million bits or 1, 048, 576 bits since the latter number more closely adheres to the binary arithmetic that lies at the heart of computer technology. On the other hand “mega” has long signified one million in the decimal system and is most widely understood in this way.

    Megabits per second describe the rate of transfer of data as measured in megabits.

    Multi-carrier Code Division Multiple Access. This 3G standard is an evolution of IS-95, combining three IS-95 carriers to form one wideband carrier. It is also known as cdma2000.
    Megahertz (MHz)
    A unit of measurement for frequency equal to 1, 000, 000 Hertz. 1 million cycles per second.

    Micro browser
    A Web browser optimized to run in the low-memory and small-screen environment of a Net device.
    Micro Cells
    In large cities, mobile phone operators are increasingly converting their networks to small cell structures (cells). Larger mobile phone cells with diameters from 10 to 20 miles are “macro cells”. Radio cells in the mid- range (with a diameter of about one mile) are “micro cells”. Even smaller are pico cells, which often only range a few hundred meters. The miniaturization of radio cells allows more subscribers to be supplied over a given area.


    MMDS (Multi-channel Multi-point Distribution Service)
    a fixed wireless service for data, voice and video which operates in the 2.5 GHz band in North America and in the 3.5 GHz bandwidth internationally.

    MMS (Multimedia Messaging Service)
    A type of messaging comprising a combination of text, sounds, images and video.
    MNO (Mobile Network Operator)
    An operator of a wireless network for mobile phones.

    MO (Mobile Originate)
    A call outbound or originating from a mobile device

    Mobile Antenna
    Refers to any antenna mounted on a vehicle. Includes a radiating element and a mechanism to fix the antenna to the vehicle.
    Mobile IP
    Mobile IP is an Internet protocol designed to support host mobility. Its goal is to provide the ability of a host to stay connected to the Internet regardless of their location. Mobile IP is able to track a mobile host without needing to change the mobile host’s long-term IP address. For a survey paper on Mobile IP browse to http://www.cis.ohio-state.edu/~jain/cis788-95/ftp/mobile_ip/index.html
    Mobile radio network
    Network using radio frequencies to connect mobiles to the fixed or mobile network.
    An open global first-generation standard for narrowband wireless packet switched communications in the 900MHz (and lower) band for mobile terminals and fixed-to-point communications.
    A device, which modulates (mo-) and demodulates (-dem) the signal carrier on a communications channel. When binary data (information as it is stored in a computer) is transmitted from one computer to another, modulation varies the carrier to represent the data during transmission, and demodulation interprets the variations of the signal so as to recapture the original information.


    A process by which information (e.g. voice, music, data) is added to a carrier signal, such that the signal receiver can extract the information via a process called de-modulation. Three commonly used modulation techniques are Amplitude Modulation (AM), Frequency Modulation (FM), and Phase Modulation (PM).

    Literally, one pole, such as a vertical radiator operated against the earth or a counterpoise. A handheld rubber duck type of antenna will most likely be a monopole.

    A mount is the device onto which a mobile antenna attaches. It is the mechanical and electrical interface between an antenna and the vehicle.
    MS (Mobile Station)
    A mobile transceiver or mobile radio enabled device operating within a mobile network. Originally this term referred just to cell phones or handsets, but now include mobile radio modems or any device containing a mobile radio modem as well.

    The mobile switching center or MSC provides basic telephone switching services and links a mobile or cellular network with the public telephone system or PSTN.

    MT (Mobile Terminate)
    A call inbound or terminated to a mobile device.
    (Mean Time Between / before Failure / Faults) The average time (usually expressed in hours) that a component works without failure. It is calculated by dividing the total number of failures into the total number of operating hours observed. The term can also mean the length of time a user may reasonably expect a device or system to work before an incapacitating fault occurs.


    MTSO (Mobile Telephone Switching Office)
    The central switch that controls the entire operation of a cellular system.

    Multi-access portal
    A service that provides Web access from a range of mobile, fixed and cable television devices.
    Describes the facility of certain mobile stations to operate over two or more frequency bands
    Describes the facility of certain handsets to operate over more than one wireless technology. e.g. GSM, CDMA, TDMA, and AMPS. Dual mode AMPS/CDMA phones and AMPS/TDMA phones are still generally available from the original cellular network operators who continue to offer AMPS services in tandem with the newer digital network technologies.

    Refers to a common phenomenon in RF where the signal arrives multiple times at the receiver at slightly different times. If you’ve used a TV with an old-style rabbit-ear antenna, you’ve sometimes seen ghosting, where the video seems to have echos of itself extending to the right. This is due to multipath. Usually the strongest path is nearly direct from the transmitter to the receiver. However, the signal can reflect off of other objects (large buildings are particularly good at this) and that signal arrives somewhat later, since it follows a somewhat longer path. For most kinds of RF multipath is a form of interference and degrades the signal. CDMA is unique among cellular transmission standards in that it actually uses multipath to its advantage by using fingers in the rake receiver. As a result, CDMA performance is actually improved by multipath.

    Multiple Access
    Multiple Access refers to techniques used in wireless telecommunication systems that permit sharing of limited radio frequency resources among a large numbers of potential users, not all of which will require simultaneous access. The key assumption is that not all users will require simultaneous access. All the common wireless technologies, e.g. CDMA, FDMA, GSM, and TDMA, apply these techniques.

    MVNO (Mobile Virtual Network Operator)
    A company that, to end-users, appears to be a wireless network operator. Unlike a standard wireless carrier, however, an MVNO does not own the Base Station Subsystem (BSS) that Mobile Network Operators (MNO) do. MVNOs also may not necessarily own other infrastructure one normally associates with an MNO, such as MSCs, and Home Location Registers (HLRs). More importantly, MVNOs do not hold licenses to radio spectrum; instead they purchase network capacity from wireless carriers that do hold licenses and which do operate the network infrastructure necessary for wireless phone communication.


    Network Access Application
    NAM (Number Assignment Module)
    The electronic memory in the cellular phone that stores the telephone number. Phones with dual- or multi-NAM features offer users the option of registering the phone with a local number in more than one market.


    NAMPS (Narrowband Analog Mobile Phone System)
    A proposed new standard for cellular radio. NAMPS combines current voice processing with digital signaling. According to Motorola, MAMPS triples the capacity of today’s cellular AMPS system, reducing the number of dropped calls and offers a range of new performance enhancements and digital message services. NAMPS has given way to the newer, more advanced, digital technologies. See GSM, TDMA and CDMA.
    A classification of the information capacity or bandwidth of a communication channel. Narrowband is generally taken to mean a bandwidth of 64kbit/s or less.


    NAT (Network Address Translation)
    The translation of an Internet Protocol address used within one network to a different IP address known within another network.

    Net mask
    A Wireless Glossary, Acronyms and Abbreviationssystem for designating hierarchies of networks and sub-networks within the Internet has evolved that uses net masking to simplify routing and local network administration. The purpose of a net mask is to specify which part of an IP address specifies a specific host and which part designates a subnet to which the host belongs.


    NIC (Network Interface Card)
    Otherwise known as a wireless LAN card. In most cases, this board or PCMCIA device is added to a computer or portable device to give it wireless LAN capabilities, but increasingly, manufacturers are incorporating network interface circuitry into portable devices, thereby eliminating the need for a separate network interface card.


    Perhaps the most prolific of all mobile antenna mounts is the NMO. It enables one mount, inserted in a drilled hole in the vehicle body, to be used over the lifetime of the vehicle with many screw-on antennas.


    Nordic Mobile Telephone System, the first mobile telephone system with automatic switching. The initiator of 1G.
    Network to Network Interface


    Node B
    A 3G name for base station
    Any unwanted signal. May include background noise, interference, or transmissions from nodes not belonging to the network. See also SNR (Signal to Noise Ratio).


    Noise floor
    In CDMA refers to the part of the incoming signal that is unusable. The primary component of the noise floor on the forward link is signals being sent by the cell to other phones in the same sector, and to a lesser extent other nearby cells and sectors transmitting to their phones. The primary component of the noise floor on the reverse link is other phones transmitting to this cell or to others nearby.

    See Wireline.


    NSS (Network SubSystem)
    The Network Switching Subsystem or NSS refers to that part of a GSM network primarily responsible for interconnection to the Public Service Telephone Network (PSTN), collecting charging information, maintaining subscriber profile and service information, wide area mobility management etc. The principal components are the MSC, or switch, the Home Location Register (HLR) and the Visitor Location Register (VLR).

    National Telecommunications and Information Administration. The US federal government’s spectrum management authority.
    Original Equipment Manufacturer

    Orthogonal frequency-division multiplexing is a method of digital modulation in which a signal is split into several narrowband channels at different frequencies. OFDM is similar to conventional frequency-division multiplexing (FDM). The difference lies in the way in which the signals are modulated and demodulated. Priority is given to minimizing the interference, or crosstalk, among the channels and symbols comprising the data stream. Less importance is placed on perfecting individual channels.
    Operators Harmonization Group. A group of industry operators established to meet on harmonization issues. The group is working towards a way of harmonization between CDMA2000 and W-CDMA.
    An antenna providing a 360-degree transmission pattern. This type of antenna is used when coverage in all directions is required.
    (“composed of right angles”) is a technical term referring to a certain special characteristic of the long code, the short code and the Walsh codes. It refers to the fact that, for instance, if you take any two Walsh codes and XOR them together, the result will be 32 1’s and 32 0’s. But if you XOR a Walsh code with itself, the result is 64 0’s. The short code and long code are orthogonal to themselves at different offsets. What this means is that if two short codes are synchronized, then the XOR of them is all 0’s. If they are offset from each other, by any amount, then the XOR of them is about half 1’s and about half 0’s. The long code is also orthogonal to itself. This was done deliberately and without it CDMA wouldn’t work. This fundamental characteristic of the long code, short code and Walsh codes is what makes it possible for the rake receiver to separate out the chip sequence intended for this phone from the ones being sent to all the other phones.


    OSI (Open Systems Interconnection)
    OSI is a standard description or “reference model” for how messages should be transmitted between any two points in a telecommunication network. Its purpose is to guide product implementers so that their products will consistently work with other products. The reference model defines seven layers of functions that take place at each end of a communication. Although OSI is not always strictly adhered to in terms of keeping related functions together in a well-defined layer, many if not most products involved in telecommunication make an attempt to describe themselves in relation to the OSI model. It is also valuable as a single reference view of communication that furnishes everyone a common ground for education and discussion. For more information on the OSI 7-Layer Model browse our AIRSOURCE Knowledgebase at https://support.airdesk.net > solution #375

    OSTL (One Time Subsidy Lock)
    A password that allows a user to configure parameters that are normally not accessible. The OTLS is in effect for only one session. See also MSL.
    Observed Time Difference of Arrival is similar to E-OTD, but may provide lower yield (percentage of successful position determinations) and operates only on UMTS networks. Accuracy: 50-200m.
    When a quantity of data is to be transmitted over a network, it is sometimes divided into groupings of sequential bits called packets. Communications and error control information is then added to the packet prior to actual transmission. At the data destination, the extra control information is removed and the original information is reconstructed from the individual packets.

    Packet Switching
    A generic term for data communications techniques that move data from place to place in a network on an individual packet basis rather than by allocating a dedicated link. Packets can be routed independently so as to maximize network capacity and to take advantage of routing alternatives to work around network bottlenecks or outages. A method of transmitting messages through a communication network, in which long messages are subdivided into short packets and routes to its final destination.

    Is a message sent by the cell system on the paging channel to a particular phone that says that there’s an incoming phone call. When the phone receives a page, it sends a message to the system requesting a traffic channel, and when it is granted one it then rings to tell its owner that a phone call is waiting.

    Paging channel
    In CDMA is a channel used by the cell to send pages, which indicate incoming calls, to the phone. The Paging channel also carries other information, such as indications of voice mail, SMS indications, plus housekeeping information such as the PN Offsets of all nearby cells and sectors.


    PAN (Personal Area Networks)
    A Personal Area Network typically covers the few meters surrounding a user’s workspace and provides the ability to synchronize computers, transfers files and gain access to local peripherals like printers and a range of pocket hardware. A technology like Bluetooth may enable wireless PAN.
    Parabolic Antenna
    An antenna consisting of a parabolic reflector and a radiating or receiving element at or near its focus. A parabolic antenna is very directive and includes a preliminary source and a parabolic reflector to focus the energy.
    Printed Circuit Board.
    PCN (Personal Communication Network)
    This standard corresponds to a high-frequency version of the GSM standard.

    Stands for personal communication system and according to the FCC it refers to any portable phone system that operates in the 1900 MHz band allocated for such systems. Among others, this includes J-STD-008, GSM and IS-136. Any of several types of wireless, voice and/or data communications systems, typically incorporating digital technology. PCS licenses are most often used to provide services similar to advanced cellular mobile or paging services. However, PCS can also be used to provide other wireless communications services, including services that allow people to place and receive communications while away from their home or office, as well as wireless communications to homes, office buildings and other fixed locations.

    PDA (Personal Digital Assistant)
    A handheld computer that can be used for simple Personal Information Management (PIM) functions. As PDAs have become increasingly sophisticated, some are poised to usurp the place of subcompact notebook computers, and can be used for more complex functions such as viewing and editing documents, spreadsheets, and presentations.
    PDAs run on a variety of Operating Systems (OS), the most common of which are the Palm, Microsoft Pocket PC, Symbian, and Linux.

    PDC (Personal Digital Cellular)
    A Japanese standard for digital mobile telephony (800 MHz and 1500 MHz bands).


    Position Determining Entity
    PDP (Packet Data Protocol)
    The primary protocol(s) used for packet data communications on a packet data network, e.g. TCP/IP on the Internet.

    PDP Context
    In order to use a GPRS network, the MS and the Network must negotiate a set of parameters that support the flow data traffic to and from the MS in an orderly fashion. Among the parameters that must be set are: the identifier of the external packet data network the MS wishes to communicate with, a PDP address recognized in that network (e.g. an IP address for service over the Internet), the address of the GGSN, QoS and so forth. The set of these parameters taken together is called a PDP context. Individual parameters may change over the life of the context as the MS moves about the network. Likewise an MS may have several contexts active at one time so as to be able to simultaneously set up and maintain sessions in more than one network, e.g. the Internet and a Corporate Intranet.

    Protocol Data Unit. OSI (Open Systems Interconnection) terminology for a generic “packet”. A PDU is a message of a given protocol comprising payload and protocol-specific control information, typically contained in the header. PDUs pass over the protocol interfaces which exist between layers of protocols (per OSI model). Basically, PDU is OSI terminology for “packet”. A PDU is a data object exchanged by protocol machines (entities) within a given layer. PDUs consist of both data and control information that allows the two to coordinate their interactions.

    Predicted Fundamental Failure Rate

    PHS (Personal Handyphone System)
    Digital mobile telephone system according to Japanese standard (1900Mhz).

    Physical layer
    The part of the device interacting with the medium. For a wireless LAN, the physical layer is the radio.


    Cell Very small cell in a mobile network for boosting capacity within buildings.
    Pilot channel
    In CDMA is a special channel that the cell transmits constantly. It is not modulated using the long code and it uses Walsh code channel 0, which is all 0’s, and it transmits a bit pattern of all 0’s. That means that what it contains is the short code at the phase being used by the cell. System acquisition by the phone begins by locating the pilot channel, and this permits the phone to synchronize its short code with the cell. After this, the phone looks for the sync channel.

    Personal Information Management functionality started with the Filofax, with all your personal data held in paper form in a single package. The personal organizer came along to store the data electronically with the ability to store the same information on your PC and synchronizes the two. The same functionality is now finding its way into mobile phones, which also have the synchronization capability.
    Personal Identification Number.

    Planar Array
    An antenna in which all of the elements, both active and parasitic, are in one plane.
    PLL (Phase Locked Loop)
    Circuit technology (or a circuit using that technology) in which the circuit is operated at an arbitrary frequency by forming a loop circuit that synchronizes the frequency phase.

    PLMN (Public Land Mobile Network)
    Today the term ‘Public Land Mobile Network’ refers to any wide area wireless or ‘cellular’ phone system. In the GSM world, inter-PLMN connections are generally restricted to other GSM networks providing similar services.


    PN Offset
    See Short code

    PN Roll
    See Short code


    A communications channel running from one point to several other points.
    A communications channel running from one point to another.


    The sense of the wave radiated by an antenna. This can be horizontal, vertical, elliptical or circular (left or right hand circularity) depending on the design and application.
    Port number
    TCP and UDP provide an address mechanism, the port number, for identifying different applications communicating from the same IP address. Thus an active web browser and an independently active mail program operating from the same IP location would typically use different port numbers so that packets are correctly delivered to specific applications.


    POS (Point-of-Sale) Terminal
    a device that accepts credit/debit card payments.


    Power control bits
    In CDMA are chips which are altered in the forward link to permit the cell to adjust the transmit power of the mobile phone on the reverse link while in a call. They are transmitted 800 times per second and cause the phone to increase or decrease it’s transmit power by a small increment.


    Printed Antenna
    All antennas made by means of a printed circuit process.
    Stands for Preferred Roaming List, and it is used by the phone to locate different cell systems. For a more detailed description log onto our AIRSOURCE Knowledge base > AIRDESK Solution number 360.


    Proactice RUIM
    RUIM, which is capable of issuing commands to the Terminal.
    Proactive RUIM session
    Sequence of related UTK commands and responses. A proactive RUIM session starts with the status response ’91 xx’ (proactive command pending) and ends with a status response of ’90 00′ (normal ending of command) after Terminal Response.


    Formal set of rules governing the format, timing, sequencing, and error control for data exchanges between two or more communications nodes. Note that many protocols may be required and regularly used on network.

    In an enterprise that uses the Internet, a proxy server is a server that acts as an intermediary between a workstation user and the Internet so that the enterprise can ensure security, administrative control, and caching service.


    PSAP (Public Safety Answering Point)
    The state-funded call center that receives all 911 calls and routes the calls to the appropriate emergency agency.
    Packet Switched Data is a technology where the communication “pipe” is shared by several users, thus making it very efficient. The data is sent to a specific address with a short delay. This delay depends on how many users are using the pipe at any one time as well as the level of priority requested for your information. Charging is made according to the volume of data and not the duration of the connection. PSD is the technology used for data communication across the Internet and because it maximizes the use of the network, this type of communication will eventually be used even for voice communication, with a high level of priority assigned to that form of traffic.
    PSK (Phase Shift Keying)
    Phase-shift keying (PSK) is a method modulating a carrier signal by rapidly changing or shifting the signal wave phase as a method of sending information. Patterns of 1’s and 0’s can be sent via prescribed phase shifts.

    PSTN (Public Switched Telephone Network)
    The PSTN refers to the world’s collection of interconnected, voice-oriented public telephone networks, both commercial and government-owned. It’s also referred to as the Plain Old Telephone Service or “POTS”.

    PTCRB (PCS Type Certification Review Board)
    the purpose of the PTCRB is to provide the framework within which GSM Mobile Equipment (ME) Type Certification can take place for members of the PTCRB. This includes determining the test specifications and methods to implement Type Certification for GSM Mobile Equipment.
    The goal of the PTCRB is if one carrier approves a Mobile Station (MS) then this MS is allowed to roam on all networks wherever they have roaming agreements in the GSMNA (GSM North America). www.ptcrb.org
    Push Technology
    A generic term applied to the methods, products or services used to deliver information to an Internet user, without the user specifically requesting that item of information.

    QAM (Quadrature Amplitude Modulation)
    A modulation technique, using variations in both signal amplitude and phase to convey information. This technique allows up to 128 data-encoded symbols to be represented per hertz (signal cycle).


    QoS (Quality of Service)
    A measure of how reliable a carrier’s service is. Usually expressed in terms of availability and measured, as how often available, by .99999 or five nines, which is the top level of reliability.

    R&TTE or RTTE (Radio & Telecommunications Terminal Equipment)
    Regulatory agency for the European Union. Purpose: Protection of the health (SAR) and the safety of the user. Govern protection requirements with respect to electromagnetic compatibility. Efficient use of the spectrum allocated to space terrestrial/radio communication. http://europa.eu.int/comm/enterprise/rtte


    RA (Routing Area)
    For purposes of GPRS mobility management the concept of routing area has been added to the basic concepts of GSM. It can be thought of as an IP sub network and is always served by just one SGSN.

    Radiation Pattern
    The graphical representation of the relative field strength radiated from an antenna in a given plane, plotted against the angular distance from a given reference.

    A discrete conductor radiating RF energy in an antenna system.
    Radio interface
    System enabling a mobile terminal to communicate with the network. Numerous discussions were held within ETSI in 1997 on the standardization of a radio interface for UMTS. On 29 January 1998 the SMG committee adopted the UMTS Terrestrial Radio Access standard (UTRA). UTRA was adopted by the ITU in March 1999 as a radio interface standard for IMT 2000.
    RADIUS (Remote Authentication Dial-In User Service)
    Radius refers to a client/server technique that enables remote access servers (RAS) to communicate with a central server, the Radius server, to authenticate dial-in users and authorize their access to the requested system or service.

    A typically rigid dielectric cover over the radiating portion of an antenna, and nearly always separated from the radiator by an air gap. A radome (the merger of radar and dome) has the purpose of protecting the radiator from natural weather phenomena and contamination by dirt. It usually includes aerodynamic shaping to minimize wind loading.
    RAI (Routing Area Identifier)
    Each routing area is assigned an identifier (RAI) by the network and is broadcast over the area by the network. A GPRS mobile station monitors the broadcast RAI, and when an RA border has been crossed, it must notify the network that it has moved to a new routing area.


    Rake receiver
    is the digital section of a CDMA receiver which permits the phone (or cell) to separate out the relevant signal from all the other signals. The relevant signal will be encoded with a known Walsh Code and a known phase of the Short code, and the rake receiver can do this because the Walsh codes are orthogonal and the Short code is orthogonal to itself at different offsets. The rake receiver is capable of receiving multiple signal sources and adding them together using multiple fingers, each of which has the ability to use a separate phase of the short code and long code and a separate Walsh code if necessary. Different fingers might track multiple signals from the same cell (arriving at slightly different times due to multipath) or might track separate cells due to soft handoff.

    RAS (Remote Access Server)
    A remote access server handles users seeking access to network from a remote or outside location. It may provide gateway/bridge functions between the PSTN or Internet and an enterprise internal network. It also provides authentication services to prevent unauthorized parties from gaining access to the network it serves.


    Receiver (Rx)
    An electronic device which enables a particular signal to be separated from all and converts the signal format into a format for video, voice or data.
    In CDMA is a process where the phone turns its transmitter on briefly and sends a packet on the paging channel that identifies the phone to the cell system. The phone does this when it first acquires the system. On most systems, it does this periodically (at a time interval selected by the cell system, typically every ten or twenty minutes). The registration message contains part of the phone’s NAM, which the phone system uses to look up the phone’s ESN. (If you are roaming, the roaming system asks your home system to look up the ESN.) The phone also registers if it changes zones, and can be challenged by the system to register.


    Relative Antenna Power Gain
    The ratio of the average radiation intensity of the test antenna to the average radiation of a reference antenna with all other conditions remaining equal.
    Reverse link
    In wireless refers to the radio link from the phone to the cell.


    Stands for “Radio Frequency” and is a commonly used acronym to refer to a radio link, e.g. “goes over RF to the cell”.


    Radio Frequency Data Communications/Radio Frequency Identification.


    Ring Indicator

    1. The ability to move between cells of the same network. 2. The ability to use a cellular phone outside one’s providers’ home service area. Providers often set up Roaming Agreements with other providers in different geographic locations. A roaming agreement lets a caller seamlessly make calls in the other provider’s geographic service area without operator intervention.


    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 “packets” which are sent to their destinations. A router is a network resident computer whose job it is to route data traffic to and from other points on the networks to which it has access. It accomplished this through the use of special addressing and routing protocols such as IP.

    RSSI (Received Signal Strength Indicator)
    Provides a signal for logic circuit processing that is a function of received RF signal strength. RSSI is used both by the switch and the mobile or portable.


    Request To Send

    Radio Transmission Technology. An air interface or standard for mobile phone transmissions.


    RUIM application session
    Execution of a sequence of commands internal to the RUIM that can result in the performance of one or several proactive RUIM sessions. The RUIM application session can be started by any event in the card session, and can execute for the duration of the card session. Processing of the RUIM application session will not interfere with normal CDMA operation.
    A data traffic detail record created by the SGSN, which may subsequently be used for billing purposes.

    Stand for Satellite UMTS. A satellite-based system that, independently of the terrestrial mobile networks and can provide some of the ground based UMTS system’s capabilities.
    Supervisory Audio Tone. One of three tones in 6 KHz region transmitted by the cell site and transponded (returned) by a cellular telephone.
    Satellite Mobile Phone
    There are various satellite- supported mobile phone networks. The oldest network, “Inmarsat”, requires large terminals. The “Iridium” network developed by Motorola and other companies came out with much smaller terminals, proved to be an economic failure, and is no longer in operation. In principle the ITU specifications for IMT-2000 also provide for optional satellite supply. They would come into question for UMTS supply in sparsely populated areas, deserts, or on the open seas. Because of the poor economic track record of satellite mobile phones to date, however, no concrete steps for satellite use in future UMTS networks are planned.
    Satellite network
    Network using radio frequencies relayed by satellite.
    SAW (Surface Acoustic Wave) filter
    A filter that uses surface elastic waves that are transmitted across the surface of a piezoelectric material. This implements a filter that has the resonant frequency and its vicinity as the pass band.

    SCADA (Supervisory Control And Data Acquisition)
    SCADA systems are used extensively by power, water, gas and other utility companies to monitor and manage distribution facilities. They are also used to monitor and control end user usage levels for purposes such as remote meter reading and load shedding.

    Space Division Multiple Access, A technique makes it possible to increase the capacity of a cellular mobile radio system by taking advantage of spatial separation between users. The base station does not transmit the signal to the entire cell area, as in conventional access techniques, but concentrates power in the direction of the mobile unit for which the signal is directed, reducing it in the directions where other units are present.


    In CDMA is a process where the phone scans the phase space of the short code looking for valid signals. Depending on when and how this is done, it may be looking for valid pilots, or it may be looking directly for valid paging channels. In a dual-band or dual-mode phone this may also involve attempt to find an AMPS system.

    Refers to the fact that a typical cell divides its circular coverage into several slices, sort of like a pie. The number of sectors supported is variable, but it’s common for there to be three. Each sector in CDMA will use a different PN Offset. From the point of view of the phone, there’s no difference between moving between sectors and moving between cells.

    Sectoral Antenna
    A directive antenna with a radiation pattern aperture (3 dB beamwidth) larger than 45°. Sectoral antennas are generally used for point-to-multipoint systems or combined with several antennas to create a base station.
    Service Data Unit (SDU)
    In layered systems, a set of data that is sent by a user of the services of a given layer, and is transmitted to a peer service user semantically unchanged. A Protocol Control Information (PCI) header is attached to the Service Data Unit (SDU) by the layer to form a Protocol Data Unit (PDU).
    Service provider
    the Company that sends you bills and owns your signature on a contract.
    SET(Secure Electronic Transaction)
    SET is a system for ensuring the security of financial transactions over the Internet. SET, may authenticate both user and merchant in order to approve the transaction.

    SGML (Standardized Generalized Markup Language)
    The mother of all markup languages. XML is “SGML light”. HTML is a loose application of SGML.


    Server GPRS Support Nodes.

    SGSN (Serving GPRS Support Node)
    The Serving GPRS support node or SGSN connects one or more BSCs to the GPRS backbone network, providing IP connectivity to the GGSN on the one hand and converting IP traffic to and from the formats and protocols used by the base station subsystem or BSS.

    Shield Effectiveness
    A measurement of how well the shielding material (braid, solid tape, etc.) protects the external environment from radiation produced by the center conductor.
    Short code
    Is a chip sequence that is 215 chips long which repeats every 26.666 milliseconds. Different cells and cell sectors all use the same short code, but use different phases of it, which is how the phone differentiates them from each other. The phase is known as the PN Offset. The moment when the Short code wraps around and begins again is called a PN Roll. (PN stands for Pseudo-Noise.) The chip sequence is designed to be orthogonal to itself at different phases.

    SID (System Identification)
    A five-digit number that indicates which service area the phone is in. Most carriers have one SID assigned to their service area.

    Signal strength
    Refers to the total amount of power of RF received by the receiver. This is divided into useful signal, referred to as EC/I0, and the noise floor which is useless.

    Subscriber Identity Module


    SIM Card (Subscriber Identity Module)
    The Subscriber Identity Module is a subscriber removable printed circuit and chip set card that must be present in GSM phones before they are recognized by a GSM network. The SIM holds information identifying the subscriber to the network. The most recent generation of SIMs are application programmable as well.

    SIM Toolkit
    A standard for value added wireless services that allows the end-user to establish an interactive exchange with network applications.

    Slot cycle
    Is a setting that controls the length of a slot. A slot is (1.28 seconds) * (2 ^ slot cycle). So slot cycle 0 is 1.28 seconds, slot cycle 1 is 2.56 seconds, and slot cycle 2 is 5.12 seconds. The longest slot cycle is 7, which is 163.84 seconds. The slot cycle is controlled by the cell. The advantage of a short slot cycle is that it means that the phone gets more chances to receive a page before the call is routed to voice mail. However, this makes the phone use more power, so standby time is not as good. It also means that the paging channel has less capacity. A longer slot cycle provides more capacity on the paging channel and lengthens standby time, but also means that the phone has fewer opportunities to receive a page, so that it’s more likely to miss it and have the call go to voice mail. You as a user cannot choose a slot cycle.

    Slotted sleep
    Is a mode of phone operation where the phone shuts down nearly all of its electronics most of the time. (All digital phone standards include a form of this. AMPS does not, which is why AMPS battery life is so poor.) The phone wakes on every slot (see slot cycle) to see if it gets paged on the paging channel. Because most of the electronics is turned off most of the time, this uses very little power from the battery. More information about this can be found here.

    Smart Antenna
    It solve the capacity problems of mature mobile cellular networks. By directing radio signals to an intended target rather than broadcasting throughout the entire cell area, they increase the network’s capacity. The more elaborate smart antenna systems can communicate with multiple mobile stations in the same cell, on the same channel, thereby exploiting their spatial separation.
    Surface Mounted Design

    SMS (Short Message Service)
    (Short Messaging Service)”Text Messages” is a mechanism that allows brief text messages (up to 160 characters) to be sent to the phone. Several of the major phone standards support it.


    Soft handoff
    Refers to a feature of CDMA where a phone can communicate simultaneously to two or more cells, or in some cases with two sectors on the same cell. This often happens when the phone is about halfway between the cells or on the dividing line between sectors, and permits the call to continue even though the signal from any one cell would not be strong enough to keep the call up. No other phone standard has this ability. For more on this, browse the AIRSOURCE Knowledgebase, solution # 378.

    Software radio
    An emerging technology, which allows network operators to simultaneously support multiple communications standards (GSM, CDMA, W-CDMA, 3G etc) on the one network infrastructure without begin bound by a particular standard.
    The range of electromagnetic radio frequencies used in the transmission of sound, data and television.
    SS7 (Signaling System 7)
    SS7 typically employs a dedicated 64-kilobit data circuit to carry packetized machine language messages about each call connected between and among machines of a network to achieve connection control. International equivalent to Bell DNHR. The SS7 protocol consists of 4 basic sub-protocols: 1) Message Transfer Part (MTP), which provides functions for basic routing of signaling messages between signaling points. 2) Signaling Connection Control Part (SCCP), which provides additional routing and management functions for transfer of messages other than call setup between signaling points. 3) Integrated Services Digital Network User Part (ISUP), which provides for transfer of call setup signaling information between signaling points. 4) Transaction Capabilities Application Part (TCAP), which provides for transfer of non-circuit related information between signaling points. Two major capabilities of SS7 are: 1) Fast call setup, via high-speed circuit-switched connections. 2) Transaction capabilities which deal with remote database interactions.

    SSL (Secure Sockets Layer)
    Protocol for managing the security of message transmissions in a network. The idea is that the programming for keeping your messages confidential ought to be contained in a program layer between an application (such as your Web browser)

    Standard Impedance
    The nominal impedance associated with the transmission line and test equipment.
    Standing Wave Radio (SWR)
    See VSWR.


    Streaming Media
    Technical term for digital audio or video transmissions via the Internet. The sound and image data are sent as a data stream to the subscriber, hence the term “streaming”. A variety of deferred data streams can be output from a streaming media server on the Net. Each receiver can thus receive the same content deferred. Normally, a packet- switched or asymmetric transmission method is used.
    On a telecommunications network, switching means routing traffic by setting up temporary connections between two or more network points. This is done by devices located at different locations on the network, called switches (or exchanges). The basic structure of a telecommunications network therefore comprises transmission media, interconnected by exchanges. “Packet” and “circuit” switching are two techniques used by telecommunications networks. The first is used by IP networks, and the second by traditional networks (PSTN).


    A joint venture originally set up by Ericsson, Nokia and Psion to develop an industry standard operating system for mobile multimedia terminals (EPOC).
    Sync channel
    In CDMA is a special channel which is always transmitted by the cell. It is not modulated by the long code. It repeatedly transmits a sync channel message that contains information about the cell and the phone system, and also contains information which permits the phone to determine the absolute wall clock time. The phone looks for the sync channel as the second step of system acquisition, and uses it to synchronize its long code generator. Once the sync channel message has been processed, the phone has sufficient information to begin to process the paging channel and to register.


    Type of transmission in which the transmission and reception of all data is synchronized by a common clock and the data is usually transmitted in blocks rather than individual characters. Can also mean that the data stream has the same capacity in both directions.
    Synchronous mode
    standard for data transmission – data is transferred without start and stop bits together with a clock signal to synchronize the receiver. This mode gives higher data throughput than asynchronous mode, but can be less secure.


    Type Approval Code


    TACS (Total Access Communications System)
    A short-lived cellular telephone system developed for use in the U.K. TACS is a derivative of AMPS (Advanced Mobile Phone System), the analog cellular standard developed by Motorola and widely deployed in the U.S. and other parts of the world. TACS operated in the 900MHz band, supporting 1,000 voice grade channels. TACS gave way to GSM, which is a muxch better digital technology. JTACS (Japanese TACS), which operated in the 800 and 900MHz rages, suffered a similar fate. See also AMPS and GSM.


    TCB (Telecommunications Certification Body)
    A TCB is a non-governmental body accredited by ANSI to review applications and issue FCC Certification grants of approval for devices requiring approvals.

    Transmission Control Protocol (TCP) is used to provide reliable data transfer between two IP endpoints but is not as fast as UDP.


    Transmission Control Protocol (TCP), and Internet Protocol (IP) together define the basic rules for how information is transmitted across the Internet (as well as on most LANs) in packetized form.

    Siemens developed this special transmission method for UMTS together with the China Academy of Telecommunications Technology (CATT). TD-SCDMA is to be used for setting up UMTS mobile phone networks in China. It combines the SCDMA technique developed by CATT with the TD-CDMA method proposed by Siemens and other manufacturers. The S in ‘SCDMA’ refers to the special synchronous mode: All radio base stations transmit and receive synchronously: they prevent unavoidably occurring feedback interferences with asynchronous radio methods. An advantage of the TD-SCDMA technique is that it is also suitable for unpaired frequency ranges (frequencies, duplex separation).


    Time Division Duplex. This will be the second variation of W-CDMA, which will be standardized towards the end of 2001, to appear commercially towards the end of 2003. This version is especially suited to indoor environments where there is a need for high traffic density.
    TDMA (ANSI-136)
    “TDMA” has been adopted as the new name for the “Digital AMPS” (D-AMPS) mobile standard, now called ANSI-136, used in the Americas, Asia Pacific and other areas. TDMA services can be delivered in the 800 MHz and 1900 MHz frequency bands.


    TDMA (Time Division Multiple Access)
    TDMA is a communications technique whereby multiple users can share a physical radio channel by being assigned specific, rotating time slots for transmitting and receiving. TDMA is also used sometimes to refer specifically to the standard covered by IS-136, which is a source of confusion because GSM also uses a TDMA air interface, as does IDEN, and neither of those systems are compatible with IS-136.

    Time Difference of Arrival. One of the simpler network-based methods, TDOA uses the time it takes for a signal to travel as an indirect method of calculating distance. With a minimum of three base stations receiving a signal from a handset, triangulation can determine the position of the MS. To achieve accurate positioning, the base stations must be precisely synchronized in time, which is usually done by GPS. Accuracy: 100-200m.
    Terminal Equipment

    A generic term for a wireless network supporting the collection and dissemination of data. Static, or fixed applications including SCADA (Supervisory Control And Data Acquisition), which is used in the power utility industry for meter reading and load control. Mobile applications include vehicle tracking and positioning, on-line navigation, and emergency assistance.

    A terminal can be a notebook computer, PC, TV, phone, mobile device, appliance etc.
    TIA (Telecommunications Industry Association)
    The Telecommunications Industry Association (TIA) is the leading U.S. non-profit trade association serving the communications and information technology industry, with proven strengths in market development, trade shows, domestic and international advocacy, standards development and enabling e-business. Through its worldwide activities, the association facilitates business development opportunities and a competitive market environment. TIA provides a market-focused forum for its member companies, which manufacture or supply the products and services used in global communications. http://www.tiaonline.org/


    TID (Tunnel ID)
    Packets traveling along the GPRS backbone are ‘wrapped’ inside an additional addressing layer to form GTP packets. Each GTP carries a TID or Tunneling identifier which tells the SGSN and GGSN whose IP packet is contained inside. In affect it associates the IP address of the packet with the ISMI.

    Tier 1
    Tier I is the initial support provided to both educate the customer and help guide the customer to the most effective solution selection. All Tier I support is provided from publicly published documents and procedures provided by AIRDESK’s vendors as well as AIRDESK itself. The customer can browse the AIRDESK support site for documents and request assistance via the web interface.


    Tier II
    Tier II technical support provides the tools and knowledge for the integrator and developer to bring their project to completion. Advanced industry knowledge is brought to the customer’s fingertips with direct access to the AIRDESK’s knowledgebase as well as access to the Technical Support team at AIRDESK. The knowledgebase includes all documented issues and their solutions provided both by the manufacturers as well as AIRDESK in a searchable web based database. AIRDESK personnel will be available to work through issues using the SDK/MDK/MSK’s and starter kits. Escalations transferred to Tier III.


    Tier III
    Takes on escalations as required from Tier II. Tier III Technical Support involves all non-documented issues and solutions. Engineering resources both at the manufacturer and at AIRDESK will be employed to bring the issue to resolution. AIRDESK will requires clear documented issues from the customer so that AIRDESK may engage the issue with the engineers it deems necessary. AIRDESK acts as the customer’s liaison to the manufacturer. The customer will need to clearly document the outstanding issue(s), and work with both AIRDESK directly and the manufacturers indirectly to resolve the issue. Communication may include Email, web interface as well as phone conversations for all parties involved.


    Tag, length, value
    Time of Arrival. Similar to the TDOA technique, this technology only differs in that it uses the absolute time of arrival at a certain BTS rather than the difference between two stations. Three BTSs are required to resolve the precise position of a MS. Synchronization of the network base stations is important. Accuracy: 100-200m.


    Traffic channel
    Is a channel which carries a phone call. When a phone wants to set up a call, it makes a request to the cell on the paging channel and the cell system sends back a message telling it which traffic channel to use (in other words, which Walsh Code to use).

    Transmission Line
    The connecting link, which allows the radio frequency energy generated by the transceiver to be delivered to the antenna. (Coaxial Cable, microstrip or coplanar lines in our industry.)


    An electronic device consisting of oscillator, modulator and other circuits that produce a radio electromagnetic wave signal for radiation into the atmosphere by an antenna.
    A phone which can operate on three bands, typically a GSM phone operating on 900 MHz, 1800 MHz, and 1900 MHz.


    Triple-band (Tri-Band)
    It means phone understand the American 1900MHz frequency band as well as the European 900MHz and 1800MHz.
    Telecommunications Technology Association of Korea. The purpose of TTA is to contribute to the advancement of technology and the promotion of information and telecommunications services and industry as well as the development of national economy, by effectively establishing and providing technical standards that reflect the latest domestic and international technological advances, needed for the planning, design and operation of global end-to-end telecommunications and related information services, in close collaboration with companies, organizations and groups concerned with information and telecommunications such as network operators, service providers, equipment manufacturers, academia, R&D institutes, etc. http://www.tta.or.kr


    TTS (Text-to-Speech)
    The flip side of speech recognition, TTS takes written words and converts them to speech. Thus, when a caller requests specific information from a voice portal, such as driving directions, TTS reads the directions to the caller. Early TTS efforts were slow and were usually read by a computerized voice that was often referred to as “Igor” because of its similarity
    to the voice of the character of the same name in old horror movies. Current TTS technology is much more natural sounding, and in some situations the caller would be challenged to differentiate TTS from an actual human speaker.
    User Agent. Software that interprets WML, WMLScript, WTAI and other forms of code. Explorer, Netscape and Opera, are examples of UA’s)


    UDP (User Datagram Protocol)
    User Datagram Protocol is used to provide fast data transfer between two IP endpoints, but is not as reliable a method as TCP.

    User Equipment


    USIM Integrated Circuit Card. The UICC is the chip card used in mobile terminals in 3G telecom networks-Systems. The UICC is an essential component for UMTS, just as the SIM is for GSM. Extending the concept of the SIM card, the UICC contains the USIM application and also provides a platform for other IC Card applications. It ensures the integrity and security of all kinds of personal data, enabling secure support for all kinds of multi-application schemes.
    SIM card equivalent planned for W-CDMA handsets.


    UMTS (Universal Mobile Telecommunications System)
    This is almost universally subscribed to standard for the third generation and is generally based on W-CDMA (Wideband Code Division Multiple Access). UMTS will launch in 2002, but full services for the general public will not arrive until around 2005. It promises a permanent internet connection of at least 384kbps and up to about 2mbps, combined with highly integrated devices and a super-fast back end.
    Most data-communication connections are bi-directional. The direction toward the remote user is referred to as the “downlink”. The direction away from the remote user is referred as the “uplink”.


    The Universal Resource Locator is used to give Web addresses for HTML, VRML, WAV and other files. It simply contains the Internet address of the machine containing the data and the directory path to the file. The URL may also include information on what access methods to use.


    Set of applications and related procedures that may be used during a card session.


    UMTS Terrestrial Radio Access. A term use for UMTS radio access solution, applied to W-CDMA and TD-CDMA.
    UMTS Terrestrial Radio Access Network. A term describing the Radio Network Controllers and Node Base stations of a UMTS network. The UMTS network, built around an IP-optimized core network carrying all traffic types. UTRAN will support both UTRA Frequency Division Duplex (FDD) and Time Division Duplex (TDD) radio interfaces allowing flexible, high-bandwidth support, and will be connected to an IP-optimized core network through a UTRAN Gateway.


    Universal Wireless Communications 136. Proposed by the TIA and adopted by the ITU for 3G, UWC-136 is a 3G TDMA standard that allows the US TDMA community to migrate from 1st (IS-136) to 3rd (UWC-136) generation systems. The standard uses a wideband TDMA technique.
    Video On Demand. A service that allows subscribers to watch programs at the time when they want


    Voice over Internet Protocol – VoIP is not simply for voice over IP, but is designed to accommodate two-way video conferencing and application sharing as well. Based on IP technology, VoIP is used to transfer a wide range of different type traffic.
    VOIP (Voice Over Internet Protocol)
    Describes the process of transmitting voice via data IP packages.


    Voltage Standing Wave Ratio (VSWR)
    VSWR of the antenna is the ratio of the maximum to minimum values of voltage in the standing wave pattern appearing along a lossless 50 Ohms transmission line with an antenna as the load.
    VPN (Virtual Private Network)
    A virtual private network (VPN) is a private data network that makes use of the public telecommunication infrastructure, maintaining privacy through the use of a tunneling protocol and security procedures. A virtual private network can be contrasted with a system of owned or leased lines that can only be used by one company. The idea of the VPN is to give the company the same capabilities at much lower cost by using the shared public infrastructure rather than a private one (expensive dedicated/leased lines).

    VSWR (Voltage Standing Wave Ratio)
    The ratio of the maximum effect voltage measured along the length of a mismatched radio frequency transmission line. Explanation: When impedance mismatches exist, some of the energy will be reflected back to the source. Different amounts of energy will be reflected back depending on the frequency of the energy. VSWR is a unitless ration from 1 to infinity, expressing the amount of reflected energy. A value of one indicates that all of the energy will pass through, while any high value indicates that a portion of the energy will be reflected.
    Wideband Code Division Multiple Access, one of two 3G standards that makes use of a wider spectrum than CDMA and therefore can transmit and receive information for faster and more efficiently. Co-developed by NTT DoCoMo, it is being backed by most European mobile operators and is expected to compete with cdma2000 to be the de facto 3G standard.
    Wideband-Time Division Multiple Access, a technique based on time division transmission which is similar to that used by GSM but provides a much higher transmission rate. It was submitted as a solution for UMTS radio interface, but was rejected.
    World Wide Web Consortium. http://www.w3c.org


    WAE (Wireless Application Environment)
    WAE specifies an environment that allows operators and service providers to build applications and services that can reach a wide variety of different platforms. WAE is part of the Wireless Application Protocol.

    Walsh code
    Is one of 64 chip patterns which are 64 chips long. CDMA channels are differentiated by which Walsh code they use. They are carefully chosen to be orthogonal to each other.


    Wide Area Network. A general term referring to a large network spanning a country or around the world. The Internet is a WAN. A public mobile communication system is a WAN.


    WAP (Wireless Application Protocol)
    WAP is a family of protocols allowing mobile devices to access wireless services.. The development of WAP is being driven by the WAP Forum, initially founded by Motorola, Nokia, Ericsson and Unwired Planet.

    WAP is a technology designed to provide users of mobile terminals with limited access to the Internet. It offers information in text form on the screen of your phones, but it’s hardly the World Wide Web.


    WAP Forum
    WAP Forum, an organization of several big Internet and telecom companies, develops the WAP protocol. http://www.wapforum.org


    WAP Gateway
    A WAP gateway is two-way software. Its main function is to offload the WAP mobile device from a lot of computational layers.

    WAP Server
    A WAP server is a web server. The computer programmers use WML instead of HTML.


    Wave Length
    See basic antenna concepts
    WCDMA (Wideband Code Division Multiple Access)
    A technology for wideband digital radio communications of Internet, multimedia, video and othersWideband Code Division Multiple Access, one of two 3G standards that makes use of a wider spectrum than CDMA and therefore can transmit and receive information for faster and more efficiently. Co-developed by NTT DoCoMo, it is being backed by most European mobile operators and is expected to compete with cdma2000 to be the de facto 3G standard.
    see DS-WCDMA
    The vertical portion of the antenna assembly, which acts as the radiator of the radio frequency energy.

    A classification of the information capacity or bandwidth of a communication channel. Wideband is generally taken to mean a bandwidth between 64kbits/s and 2Mbit/s.
    A new all-encompassing “buzzword” which describes what used to be called “radio”, but which typically also implies some of the newer cellular or digital radio technologies as well.
    Wireless Access
    A terminal access to the network that uses wireless technology.


    Wireless Telemetry
    Wireless Machine-to-Machine (M2M) communication, not including traditional data or voice-centric devices. Examples of wireless telemetry applications include: asset tracking, point-of-sale, vending, arcade games, supervisory control and data acquisition (SCADA
    Wireless Transceiver
    A wireless device, typically a modem, which transmits M2M data from the unit being monitored to a control room where it can become useful information.


    Wireline and Non-Wireline are terms used to distinguish between the two cellular carriers in a CGSA. Originally, the “wireline” carrier was an affiliate of a telephone company providing conventional landline telephone service within the area of the CGSA; the “non-wireline” carrier was the other cellular operator. In recent years, the terms simply denote whether the carrier uses the “A” block of cellular frequencies (non-wireline) or the “B” block (wireline). All cellular telephones sold in the United States must be able to use both A and B block cellular channels.

    Wireless Internet Service Provider.


    Wireless Local Area Network. A short-range computer-to-computer wireless data communications network.
    Wireless Metropolitan Area Network. A regional wireless computer or communication network spanning the area covered by an average to large city.


    Wireless Markup Language. Wireless Markup Language is a markup language developed specifically for wireless applications. WML is based on XML.


    WML Card
    A WML card must exist inside a WML deck containing one or more cards.


    WML Deck
    A collection of WML cards.

    Scripting language for WAP devices. Based on JavaScript, but less powerful.


    Wireless Personal Area Network – Bluetooth Technology
    WSP (Wireless Session Protocol)
    Provides the upper-level application layer of WAP with a consistent interface for two session services, a connection-mode service that operates above a transaction layer protocol, and a connectionless service that operates above a secure or non-secure datagram transport service.


    WTLS (Wireless Transport Layer Security)
    WTLS is the “equivalent” to SSL (Secure Sockets Layer) widely used in the HTML world – although not identical in functionality.
    Wireless Transaction Protocol


    Wireless Wide Area Network. WWAN uses various devices – telephone lines, satellite dishes, and radio waves – to service in area broader than can be covered by a WLAN, although typically with lower bandwidth.
    What You See Is What You Get.

    XML (Extensible Markup Language)
    W3C’s standard for Internet Markup Languages. WML is one of these languages.

    A directional, gain type of antenna that utilizes a number of parasitic directors and a reflector. Named after one of the two Japanese inventors (Yagi and Uda).

    Refers to one or more sectors of one or more cells. It is an administrative category in CDMA. Movement within a zone does not require the phone to reregister. The phone has to register if it crosses a zone boundary.


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