2.5 G

Refers to wireless telecommunications technology that is more advanced than 2G but does not meet requirements for 3G.
An example is GPRS (g). Some observers consider EDGE (g) and CDMA 2000 1k to be 2.5, but officially they are 3G.

2G

Second Generation

Refers to the second generation of wireless telecommunications devices which are digital(g) by nature, as opposed to the first generation analog(g) devices (cell phones). 85% of all second generation (2G) devices worldwide are based on the TDMA(g)/GSM technology patented by InterDigital Communications Corporation. About 15% of the 2G devices worldwide are based on the Narrowband(g) CDMA technology largely patented by Qualcomm.

3G

3G Third Generation The "next generation" of Cellular Radio(g) for mobile telephony. 3G service was initiated in some parts of the world in 2002 and is expected to be the predominant technology for wireless communications worldwide in 2007 and beyond. 3G is the first cellular radio technology designed from the outset to support wideband data communications just as well as it supports voice communications. Promoters envision that 3G will be the basis for a wireless information society where access to information and information services such as electronic commerce is available anytime, anyplace and anywhere to anybody. 3G's technical framework is being defined by the ITU(g) with its International Mobile Telecommunications 2000 (IMT-2000[g]) program.

A brief historical perspective and more detailed description of the various modes of the 3G standards follow.

Fifteen years ago, cell phones were almost unheard of. Today they have become a mainline device for voice communication and are on the verge of meeting new challenges like high-speed data, videoconferencing, e-mail and, of course, Internet access -- all for a people "on the move."

The early analog(g) cell phones are called "first generation." Fairly similar systems, which repaired some of the deficiencies of analog(g) are called "digital" or "second generation." The services offered differ little among cell phone providers, technologies and equipment manufacturers. That means that telecom providers easily lose customers to someone else with a better promotional offer. So-called "third generation(g) " will give service providers a chance to offer unique services, thereby reducing churn and leading toward sustained growth.

Witnessing the increasing incompatibility among telecom technologies in the early 1990's, the international community, through the United Nations, became intent on providing as much standardization as possible in what would become third generation (3G) (g) Task forces have been working diligently for six years to standardize 3G, the next generation of wireless telecommunications.

In spite of the talk about a "3G standard," however, no single standard emerged when the framework for new standards was confirmed in May, 2000. Current radio transmission technologies differ enough in the details for each system to be attractive to different telephone companies, each with their own market realities, customers, applications, and previously installed equipment, besides the political realities.

The International Telecommunications Union (ITU(g) has defined five sets of standards specifications with three basic technologies within the international third generation wireless standard. These three basic technologies are:

1. TDMA-Only Standard. This standard will be entirely TDMA(g) , with no cdma(g) elements at all. This standard includes Digital Enhanced Cordless Technology (DECT) (g) and UWC-136, also known as EDGE (g). This standard is important because it provides an evolutionary path for both the old analog(g) Advanced Mobile Phone System (AMPS(g) and the second generation digital(g) technologies designed specifically to be compatible with, and correct the deficiencies of, AMPS(g) This new "economy class" standard would allow relatively speedy and low-cost development for both analog(g) and second generation digital(g), although it is officially 3G. This version might also be described as 2.75G because it is somewhere between the current second generation and the new third generation(g) (3G) standards. Clearly, InterDigital has many foundational patents on the fundamental technology inherent in this new standard and, in fact, worked closely with other industry leaders in formulating this new standard.

2. CDMA2000(g) The so-called "Qualcomm Standard", is intended to provide benefits of third generation(g) <../glossary.htm> wireless while still protecting the heavy investment some telecom providers have made in Qualcomm's narrowband(g) CDMA ("IS-95"(g) equipment and systems, most of which are in North America and Korea. This technology brings current second generation (narrowband(g) CDMA(g) equipment to third generation(g) broadband features.

3. WCDMA or UTRA Wideband CDMA(g)with FDD (g) and TDD(g) What almost everyone agrees will be the most widely used approach to the new, third generation wireless is a combination of wideband CDMA(g) air interface(g) , frequency division duplexing (g), time division duplexing (TDD(g) and GSM(g). The latter allows roaming and is by far the preferred network in over 110 countries, especially in Europe. A wide variety of worldwide telecom technology and equipment firms, including almost all the big names, have merged their various W-CDMA(g) proposals into a new standard. The intention is to take advantage of WCDMA(g) technology without ignoring the many GSM(g)

(second generation) systems in the world. These telecom leaders have come up with a technology based on the well-developed European (ETSI (g) Universal Mobile Telecommunications System (UMTS(g) <../glossary.htm>). This consensus 3G(g) system is sometimes called UTRA(g) (for UMTS(g) terrestrial radio access). Because it is compatible with the existing GSM(g) systems, it is almost certain that this standard will be, by far, the most popular. It is likely that Qualcomm will be able to offer little effective competition with its CDMA2000(g) standard, except in the United States, Korea, and maybe Japan and China. While evaluating the deployment of WCDMA and CDMA 2000, the Chinese government is also considering time division synchronous code division multiple access (TD-SCDMA).

3G3P

The Third Generation Patent Platform Partnership.

The 3G3P has brought together 41 companies and organizations to quantify just what is meant by fair, reasonable and nondiscriminatory terms for evaluating whether a patent is essential and for establishing a fair price, as well as predefining the commercial terms of the new company. Independent experts, patent lawyers and technologists will declare what IPR is an essential technology in 3G and assign it a dollar value. The new not for profit company will also incorporate an appeal procedure. Although the company's operating brief is decided, it still has no legal framework, and must wait for the go ahead from regulatory authorities, including the US Department of Justice.
3G3P was originally referred to as the UMTS IPR (intellectual property rights) Working Group when this initiative was in the planning stages under the auspices of ITU. This group has sometimes been referred to as the UMTS Intellectual Property Association. This term should not be confused with 3GPP.

3GPP

Third-generation Partnership Protocol

A global cooperative project in which standardization bodies in Europe, Japan, South Korea and the United States as founders are coordinating WCDMA(g) issues, and coordinating the writing of specifications from the WCDMA international standards of the ITUCg. See also WCDMA(g).

802.11

Air Interface

Communication of one wireless device with another via radio waves rather than wires or fiber optic lines.
Also see "testing"(g)

Air Interface Testing

See "testing"(g)

AMPS

802.16

Advanced Mobile Phone System

First Generation (1G)Cellular Radio(g) standard developed in the USA. It is an analog(g) system which uses different frequency carriers to create communications channels in a technique known as Frequency Division Multiple Access (FDMA). AMPS is still widely used and forms the basis for a number of other cellular radio standards such as TACS(g) and D-AMPS(g). Used primarily in North America, Latin America, Australia and parts of Russia and Asia.

Analog

A form of transmission that is a continuous wave electrical signal that varies in frequency and/or amplitude in response to the variations of a physical phenomena such as human speech or music. In telephony, your voice is captured by a diaphragm within the telephone which causes a magnet to vibrate creating a continuously fluctuating electrical signal that is passed through a wire circuit and received on the other end.

ARIB

Association of Radio Industries and Businesses, headquarters in Japan. ARIB is designated as "the Realization Center for Efficient Use of Radio Spectrum" by The Minister of Posts and Telecommunications in Japan. Visit the ARIB web site.

ARM

ARM, a leading intellectual property (IP) provider, licenses high-performance, low-cost, power-efficient RISC processors, peripherals, and system-chip designs to leading international electronics companies. ARM also provides comprehensive support required in developing a complete system. ARM s microprocessor cores are rapidly becoming the volume RISC standard in such markets as portable communications, handheld computing, multimedia digital consumer and embedded solutions. ARM is sometimes referred to as the "Intel" of the processors it designs and manufacturers. More information is available at http://www.arm.com.

ASIC

Application Specific Integrated Circuit.

Integrated circuits ("chips") which are custom designed for specialized applications.

ASSP

Application Specific Standard Product

Asynchronous Mode

A method of transmitting data one bit at time with started bits, stop bits, and parity attached to each information segment. The 3G standard, WCDMA, is asynchronous mode, while the 3G standard CDMA2000 is synchronous mode. See Synchronous Mode(g) for comparison

ATM

Asynchronous Transfer Mode

Broadband transmission technology which provides the backbone of the world's telecommunications network. ATM breaks information flows into small fixed-length cells of 53 bytes. Cells of any type of traffic – voice, multimedia, data or video – can be interspersed with each other. ATM operates at speeds of 25, 155 and 622 Mbps.

Bandwidth

The information-carrying capacity of a communications channel. Usually expressed in Hertz (cycles per second) for analog circuits and in bits per second (BPS) for digital(g) circuits.

Bandwidth on Demand

A means of allocating the minimum required bandwidth to users in a wireless system depending on their individual needs. For example, a mobile voice call requires a small amount of bandwidth, while mobile Internet access requires much more. A very important feature in both TDMA(g) and CDMA 3G systems is the allocation of bandwidth in an extremely efficient manner, increasing the capacity of a wireless system. InterDigital Communications Corp. (IDCC) claims it has one of the best "bandwidth on demand" technologies.

Base station

The central radio transmitter/receiver that maintains communications with a mobile radiotelephone with a given range.

Base Station Emulator

A unique device, utilizing TDD(g) technology, that simulates the performance of the base station in a wireless system. Originally developed by InterDigital Communications Corp. (IDCC) to permit easier, less expensive testing of TDMA(g) subscriber units, it contains core technology applicable to TDMA(g), GSM(g), PDC(g), and 3G (g) WCDMA(g) systems including bimodal phones. This basically tells if a manufacturer's "independently developed software program" or "handset prototype" will work in conjunction with the WCDMA air interface specs they have chosen. Although first tier industry leaders and specialists (like Nokia, Ericsson, Seimens, Qualcomm, Ubinetics, Agilent) have this "in house" testing capability, InterDigital says it will make this testing available to any second or third tier designer/manufacturer, potentially enabling all tiers a means of quickly determining how their respective system operates in the WCDMA environment (dropped calls, MOS[g] - voice quality, interference, modulation strength, battery consumption, antenna usage, base station controls settings, etc.). Potential revenue of various firms from testing can be significant ($2 billion plus is estimated between 2000 and 2004 as multiple companies begin to prepare new products for the 3g market place.

B-CDMAT

Broadband Code Division Multiple AccessT. InterDigital's proprietary version of high speed, wideband CDMA. Designed primarily for fixed (vs. mobile) wireless local loop, many of the B-CDMA specifications reportedly have been incorporated into the 3G WCDMA standards.

Bluetooth

A new technology designed to be embedded in electronic devices in order to provide wireless and seamless connections over short distances. The idea is to provide an easier to use alternative to the cable-based interfaces currently in use to link computers and computer peripherals. Other devices in which Bluetooth chips could be embedded include mobile telephones, personal digital(g) assistants, headsets and wristwatches.

Bps

bits per second - meaning data transmission speed, the number of pieces of information transmitted per second.

BRAN

Broadband

A term applied to telecommunications systems capable of simultaneously supporting multiple information formats at relatively high speeds such as voice, high-speed data services and video services on demand. Overall transmission speeds are typically hundreds to thousands of times faster than those of Narrowband(g) systems. Also called Wideband (g).

Bypass

Usually refers to the practice of avoiding local telephone companies' long-distance access fees to local operators by routing traffic from private networks directly to the long-distance carrier – i.e. bypassing the local carrier. With the advent of Mobile Satellite Systems(g), bypass may also now refer to the bypassing of national carriers to establish international connections.

CATT

China Academy of Telecommunication Technology

CATT is working with Siemens in the development of third generation wireless TD-SCDMA (g) technology.

Call Establishment

See Power Ramp-Up(g)

CDMA

Code Division Multiple Access

Technology straddling second generation and third generation (3G[g]) mobile Cellular Radio(g) systems. Under CDMA, communications channels are created by assigning a special coding scheme to information flows. Also called spread spectrum. Each piece of communication is given a code and then reassembled at the receiving end. Business Week writes that CDMA spreads all signals across the same frequency spectrum and assigns a unique code to each signal. The dispersal signals are pulled out of the background noise by a receiver which recognizes the code. The technology is championed by Qualcomm. Inc., who says there are 42 billion useable codes. CDMA-based second generation cellular radio systems are in use in parts of Asia and North and South America. New variations of CDMA provide the base for several third generation cellular systems. Also see: Multiple Access(g) for distinctions between CDMA, TDMA, and FDMA, all variations of "multiple access" (MA)

Newton's Telecom Dictionary says the major benefits of CDMA technology is increased capacity over analogues systems and the use of 3 features: (1) a soft hand-off, ensuring that a code is connected to a new tower before leaving the current one. (2) variable rate vocoding allowing the most efficient transmission rate, and (3) multiple signal processing techniques to increase power central for signal integrity.

Also see: Spread Spectrum(g)
Also see: Synchronization(g)
Also see: code divisim (g) Visit the CDMA portion of Qualcomm's web site for more information. Qualcomm is the chief, but not exclusive, proponent of this technology. More- see 3G standard, a wireless ledger report.

CDMA Development Group (CDG)

According to Motorola, "The CDMA Development Group (CDG) is a nonprofit trade association which was formed to foster the worldwide development, implementation and use of CDMA. Growing in recognition around the work as the governing CDMA MoU, the CDG currently represents over 44 companies including many of the world's largest wireless operators and equipment manufacturers (e.g. AT&T, GTE, Motorola, Nokia, Qualcomm, Samsung and Sony). Directors of the CDG are senior officers and executives of member organizations. The CDG's primary activities include technical development of features and services, public relations, education and seminars, regulatory affairs and international development.

CDMA2000

CDMA (code division multiple access) 2000 is a radio transmission technology for the evolution of Narrowband(g) cdmaOne/IS-95(g) to 3rd-generation adding up multiple carriers CDMA 2000 1xRTT is considered to be a 3G standard. For more information, see the Third Generation section of the Qualcomm web site . CDMA2000 is generally associated with prime supporter, Qualcomm, although other industry leaders are also involved with this technology. See also WCDMA(g) for single carrier/direct spread technology, the primary competitor of CDMA2000 technology. Visit the ITU standards web site for a diagram of the new 3G standards., which include CDMA2000. More- see 3G standards, a wireless ledger report.

CDPD

Cellular digital packet data

AT&T is offering cellular digital packet data services that provide Internet information over a wireless packet network to mobile phones.

Cellular Radio

Cellular Radio is the technology that has made wide scale mobile telephony possible – before cellular radio the problem with the mobile phone as a concept was how to get large numbers of users to share small amounts of radio spectrum. Cellular radio solved this problem by allowing the reuse of the same radio frequencies by assigning them to cells which were far enough apart to prevent noticeable interference. Frequency Division Multiple Access (FDMA[g]) was the basis for first generation cellular radio systems. Second generation cellular radio systems - the current generation - use digital(g) techniques such as TDMA(g), its cousin GSM (g)and CDMA(g) to support high bit rate voice and limited data communications. Third generation (3G[g]) systems will support voice and high bit rate data allowing mobile multimedia applications (see also Narrowband(g), Wideband(g)). More- "How cell phones work (how stuff works)

Circuit-switching

Means of creating telecoms connections by setting up an end-to-end circuit. The circuit remains open for the duration of the communication and a fixed share of network resources is tied up with no one else able to make use of them until the connection is closed. The main advantage of circuit-switching is that it enables performance guarantees to be offered. See also Packet Switching(g).

Code Division

A mean of creating multiple circuits on a single channel by assigning codes to fit a data which are reassembled at the receiving end combined with Time Division Multiplexing (g).

Compression

See Digital compression(g)

D-AMPS

Digital Advanced Mobile Phone System

TDMA(g)-based second generation (2G) cellular radio standard originated in North America. Sometimes D-AMPS is also referred to as TDMA(g) although it is not the only form of TDMA(g), with others including GSM(g) and PDC(g). D-AMPS is widely used throughout the Americas, and uses frequencies in the 800 MHz and 1900 MHz frequency bands. InterDigital claims proprietary rights to this technology.

Decoder

A device that restores a signal to its original form after it has been encoded.

DECT

Digital Enhanced Cordless Telecommunications

A standard for cordless personal telephony originally established by ETSI, a European standardization body. DECT(g) is a system for cordless business communications. It is the least popular of the 3G standards. More- 3G standards, a wireless ledger report.

Digital

A form of transmission that transforms analog signals (e.g. speech) into a series of electrical or optical pulses that represent the binary digits 0 and 1. The first step of a digital transmission is sampling the analog waveform and converting it into a stream of numerical data. This data is then converted into a form such as electronic pulses for a wired network, optical light waves for transmission over fiber optics or into radio waves for wireless transmissions. Digital networks are rapidly replacing analog ones as they offer improved sound quality, secure transmission and can handle data as well as voice. Digital networks include mobile systems GSM 900, GSM 1800, GSM 1900, D-AMPS and the cordless DECT(g) system. CDMA (g) and all 3G systems (g)

Digital compression

A way of reducing the number of bits in a digital signal by using mathematical algorithms to eliminate redundant information thereby reducing the space the signal occupies when being transmitted or recorded.

DSL

Digital subscriber line

DSP

Digital Signal Processor

A specialized digital microprocessor used to efficiently and rapidly perform calculations on digitized signals that were originally analog in form (e.g. voice). The big advantage of DSP(g) lies in the programmability of the processor, allowing parameters to be easily changed. Both Texas Instruments and Infinion Technologies are major DSP producers.

Dual band

Dual band mobile phones can work on networks that operate on different frequency bands. This is useful if you move between areas covered by different networks. For example GSM 900, GSM 1800.

Dual mode

Dual mode mobile phones work on more than one network (for example, TDMA[g] and AMPS, GSM and DECT[g]). GSA and WCDMA (g) also see triple works (g)

EDGE

Enhanced Data Rates for GSM Evolution

An enhanced modulation technique designed to increase network capacity and data rates on GSM(g) networks. EDGE, due to be introduced in 2000-2001, promises to provide a threefold improvement to current data rates without requiring new network infrastructure. Instead it is based on a major change in the GSM standard to support 8-PSK (Phase Shift Keying) based signal modulation as well as existing GSM modulation.
GSM standards bodies have been defining data networking technologies that build upon GSM. For an excellent, illustrated paper that discusses the evolution of TDMA(g)-based GSM technology from its original form through GPRS(g) and EDGE as it evolves into third generation WCDMA, which will offer data rates to 2 Mbps., See the Rysavy Research on the GSM evolution track.
Amy Karam says that in the United States, EDGE technology will bridge the gap between Time Division Multiple Access (TDMA) networks and the GSM networks more common in the rest of the world, to provide a degree of global roaming for wireless users. EDGE is the evolution of GSM and TDMA into a system capable of a 384-kbits/s data rate. Edge will allow GSM and TDMA to converge into a global network in which roaming across international and technological boundaries is possible. For more see= 3G standard, a wireless ledger report. Unfortunately, EDGE is limited by a ceiling in transmission spreads and will not be able to offer high speed modes, where refers WCDMA or CDMA.

Encoder

A device that encodes the signal before transmission.

Ethernet

The most widely-installed LAN(g) technology. Standardized as IEEE 802.3, an Ethernet LAN uses Carrier Sense Multiple Access with Collision Detection (CSMA/CD) protocol (originally developed to manage radio based data communications - hence the name Ethernet) running over a coaxial cable or twisted pair wires. The most commonly installed Ethernet systems are called 10BASE-T and provide transmission speeds up to 10 Mbps. Fast Ethernet, or 100BASE-T10, provides transmission speeds of up to 100 Mbps and is typically used for LAN backbone systems, supporting workstations with 10BASE-T cards. Gigabit Ethernet provides an even higher level of backbone support at 1 Gbps.

ETSI

European Telecommunications Standards Institute is a nonprofit making organization whose mission is to produce the telecommunications standards that will be used for decades to come throughout Europe and beyond. Based in Sophia Antipolis - a high tech research park in southern France - ETSI unites 773 members from 52 countries inside and outside Europe, and represents administrations, network operators, manufacturers, service providers, research bodies and users. Visit the ETSI web site.

FDD

Frequency Division Duplex

Full duplex operation by using a pair of frequencies, one for transmission and one for reception. FDD supports two-way radio communication using paired radio frequencies, is ideal for high volume mobile voice traffic, and is the traditional cellular and PCS radio spectrum allocation format. TDD (g), or Time Division Duplex, uses a single frequency band to transmit signals alternately in forward and reverse directions. FDD is ideal for high volume voice traffic, whereas TDD is ideal for transmitting large amounts of data such as Internet access in a mobile format. See: UTRA FDD (g) More- 3G standard, a wireless ledger report

FDMA

Frequency Division Multiple Access

A method of radio transmission that allows a large number of users to share access to a group of radio frequency channels without interference by assigning specific frequencies within the group of frequencies to each user. See AMPS(g), Cellular Radio(g)

Frame Relay

High speed transmission method, switching packets of data through its network to their destination. Access to the network is via Frame Relay Access Devices (FRADs) which translate the data (e.g. Ethernet, Token Ring) into frame relay packets. The network sets up a virtual circuit which is a path to the destination. Frame relay is more popular in the US than in Europe, but the main European carriers offer frame relay service. Frame relay can operate at speeds of up to 45 Mbps, since it is a lightweight system without error correction, relying on the integrity of the fiber optic hardware.

Frequency

The rate at which an electrical current alternates, usually measured in Hertz. Frequency equals the number of complete cycles of current occurring in one second.

FWA

Fixed Wireless Access

Term describing a general means of providing the last "mile" link to fixed telecommunications network subscribers through the use of radio technology. FWA is typically deployed in rural areas where the cost of cabled local loops can be particularly high and for projects where the rapid deployment of new telecommunications subscriber connections is particularly important. Also called WLL(wireless local loop) convert with mobile system

FPGA

Field-programmable gate array

GHz

GigaHertz (billions of Hertz).

Global Pilot Channel

See Pilot Channel / Pilot Code(g)

Globalstar

Low-Earth-Orbiting (LEO) satellite-based digital communications system.

GPRS

General Packet Radio Services

Packet Switched(g) data radio technology for GSM networks. GPRS(g) connections are always open giving mobile terminal users the same kind of network availability they may be used to from corporate networks. There are no set up and clear down times associated with data calls made via GPRS(g). Terminals can therefore effectively become a part of the Internet.
GSM standards bodies have been defining data networking technologies that will build upon GPRS(g). One such technology is called Enhanced Data rate for GSM Evolution (EDGE) which will offer a maximum theoretical rate of 384 kbps, though normal operating speeds will be about half this rate. Beyond EDGE, third generation cellular systems will eventually offer data rates to 2 Mbps. For an excellent, illustrated paper on the evolution of TDMA(g)-based GSM systems to GPRS(g) and then to EDGE and finally third generation WCDMA, see the Rysavy Research on the GSM evolution track.
General Packet Radio Service (GPRS) technology is part of the evolutionary first step toward 3G. Primarily a software upgrade to the Global System for Mobile Communications (GSM) wireless networks that provide mobile phone service in much of the world, GPRS provides mobile users with access to Internet information. It is a natural part of the migration path to 3G and uses the same base stations as GSM with a modification of software and the addition of support nodes, plus a link to a packet data network. Currently, GPRS is in trials around the world. It is sometimes referred to as 7.5G
The Third Generation Partnership Project (3GPP) (g) working group of the International Telecommunications Union is working out the issues surrounding wireless packet voice, such as quality of service, security and voice quality. That group is also working with the Internet Engineering Task Force because the issue requires a blending of the telecommunications and Internet worlds. More: "How GPs receives work" (How stuff works).

GPs

Muller 347. More: "How GPs Receives Work" (How stuff works)

GSM

Global System for Mobile communications

TDMA(g)-based second generation mobile Cellular Radio(g) technology, originated in Europe but now used in over 100 countries around the world. GSM supports voice, data and text messaging and allows roaming between different networks – which means that GSM users can take their phones with them to many parts of the world. GSM systems currently operate at 800 MHz, 900 MHz, 1800 MHz or 1900 MHz. Countries have been rapidly building up GSM networks, resulting in over 160 million fully working subscribers in over 125 countries. Eighty percent of all digital cell phones worldwide are based on GSM/TDMA(g) technology. InterDigital firsthand claim Motorola and other proprietary rights to both GSM and TDMA(g) technology.

GSM standards bodies have been defining data networking technologies that will build upon GSM. One is a technology called GPRS(g). A further evolution is called Enhanced Data rate for GSM Evolution (EDGE) which will offer a maximum theoretical rate of 384 kbps, though normal operating speeds will be about half this rate. Beyond EDGE, third generation cellular systems will eventually offer data rates to 2 Mbps. For an excellent, illustrated paper on the evolution of TDMA(g)-based GSM systems to GPRS(g) and then to EDGE and finally third generation WCDMA, see the Rysavy Research on the GSM evolution track. For information on how the GSM standard and developed see standard report.

Handoff

inter-cell handoff

The process by which subscribers traveling through a cellular system coverage area are switched from one cell to another cell (and different channels) with better coverage for that particular geographic area. InterDigita. Communications Corp. (IDCC) claims to have developed a new "seamless hand-over" method of handing over CDMA calls between cells that requires minimum system overhead and maximizes CDMA system capacity. This increases the coverage area, accommodates more users and saves battery life, according to recent company claims. See also Soft Handoff(g) more "How cell phones work" (How stuff works)

intra-cell

The process by which subscribers traveling through the coverage area of a single cell are switched from one sector to another sector (and different channels) with better coverage for that particular geographic area. See also Soft Handoff(g)

Hertz

The unit of measuring frequency (one cycle per second). See Integrated Circuit (g)

HDR (High Data Rate) High Chip Rate TDD- see widebaned TDD (WTDD)(g)

A high speed, high capacity wireless technology. HDR unleashes Internet access by providing up to 2.4 Mbps in a 1.25 MHz channel which is exceptional in systems capable of fixed, portable, and mobile services. The HDR system is optimized for packet data services, with a decentralized architecture based on IP protocols/platforms. HDR's network salability and resource optimization provides maximum utilization of network and spectrum resources. The compatibility of this technology with Narrowband CDMA networks provides further advantages with deployment and optimization costs. Apparently, Qualcomm continues to lead the development of Narrowband CDMA with the technology in this versatile wireless data solution. Qualcomm claims that in conjunction with an existing voice network, or stand-alone data network, HDR offers a high speed, cost-effective wireless data solution. For further information, see Qualcomm's web site section dealing with HDR.
See TDD (g) for an equivalent technology being developed now by Nokia and InterDigital for third generation applications.

HSCSD

High Speed Circuit Switched Data

Dedicated Circuit Switched(g) data communications technology for GSM(g) systems which boosts GSM data speeds from the regular 9.6 kbps to 14.4 kbps in a single traffic channel and, by using multiplexing(g) techniques, up to 57.6 kbps. EDGE(g) will boost HSCSD rates even further. HSCSD capabilities are available on circuit-switched networks, and should not be confused with packet-switched technologies.
For an excellent, illustrated paper on the evolution of TDMA(g)-based GSM(g) technology see Rysavy Research .

HTML

Hypertext Markup Language

Page description language used by designers of web pages to create information content for the World Wide Web. Markers such as <P> define page layout features such as New Paragraph. Elements of the page can also be set using HTML to become hypertext links to information on the same page or other pages on the web.

IMT-2000 (International Mobile Telecommunications)

A term used by the International Telecommunication Union, ITU(g), a United Nations agency, to describe the third generation mobile telephony standard due to be largely completed in 2000. Can also be applied to mobile telephone standards that meet a number of requirements in terms of transmission speed and other factors. See IMT-2000 standards (g) for a brief description of these very important standards and a link to a further explanation at the ITU web site. For a fascinating report on how standards have been determined, see (standards)

IMT-2000 Standards

The most important work of the United Nations-sponsored International Telecommunications Union (ITU) (g) standards setting body has been the determination of international standards for the third generation wireless communications. Although some refer to there being "one" standard, in effect there are five specifications or modes to this standard. The standards reflect a distillation of the strongest recommendations from various parts of the world (principally Europe, Asia and the US) and from proponents of the two major digital wireless technologies: TDMA (g) with its cousin GSM (g) and CDMA (g). Work on the standards was 90%+ competed in the Fall of 2000. The five specifications under the 3G standard include three forms of CDMA (g) technology: (1) Time Division Duplex (TDD) (g) and (2) Frequency Division Duplex (FDD) (g) - both forms of (wideband) WCDMA (g), and (3) FDD Multi-carrier CDMA (referred to as CDMA2000 (g)). The standard also includes two forms of TDMA (g) technology: (1) Digital Enhanced Cordless Telephone (DECT) (g), and (2) (UWC) IS-136 (g), an evolved form of the US IS-136 (g) digital cellular standard. For general information on the very important new international standards, see: IMT-2000 standards at the ITU web site . Visit the ITU standards web site for a diagram of the new standards. More-3G standard, a wireless ledger report

IMT-2000 Terrestrial Radio Interfaces

The IMT-2000 (g) terrestrial standard consists of a set of radio interfaces which allow performance optimization in a wide range of radio operating environments. (The term "terrestrial" is used as a distinction from other standards for "satellite" interfaces.) See diagram of standards at ITU (g) web site.

IMT-DS

International Mobile Telecommunications Direct Spread

One of the five third generation (g) standards approved by the International Telecommunications Union (ITU) (g). This is the WCDMA (g) standard also know as UTRA FDD (g) Visit the ITU standards web site for a diagram of the new standards.

IMT-FT

International Mobile Telecommunications Frequency Time

An ITU (g) third generation (g) wireless standard is more commonly known as DECT (g). Visit the ITU standards web site for a diagram of the new standards.

IMT-MC

International Mobile Telecommunications Multi Carrier

One of the ITU (g) standards (g) for third generation (g) wireless more commonly known as CDMA2000 (g) Visit the ITU standards web site for a diagram of the new standards.

IMT-SC

International Mobile Telecommunications Single Carrier

An ITU (g) third generation (g) wireless standard is more commonly known as (UWC) IS-136 (g) Visit the ITU standards web site for a diagram of the new standards.

IMT-TC

International Mobile Telecommunications Time Code

A third generation (g) wireless technology based on both CDMA (g) and TDMA (g), this ITU (g) standard is more commonly known as either (UTRA) TDD (g) or TD-SCDMA (g). Visit the ITU standards web site for a diagram of the new standards.

Infrastructure

All parts of the wireless network, excluding the subscriber handset. Includes the MTSO (switch), Base Stations, Cell Sites, and all links between them.

Interference

Static or unwanted signals producing a distortion of sounds or images and preventing good reception. See also: Joint Detection and Interference Cancellation(g)

Integrated Circuit (IC)

A device consisting of a number of connected circuit elements, such as transistors and resistors, fabricated on a single ship of silicon crystal or other semiconductor material. Integrated circuits are categorized buy the number of elements they contain.

Internet

A worldwide network of computer networks in which users at any one computer can, if they have permission, get information from any other computer. The idea was conceived by the Advanced Research Projects Agency (ARPA) of the US government in 1969 and was first known as Arpanet. Since then it has been demilitarized and commercialized and augmented by a series of inventions and innovations, not least of which is the web browser invented by a team led by Tim Berners-Lee in 1991 at CERN, the European Laboratory for Particle Physics. This is the basis for the World Wide Web which has been so successful that it is now often confused in popular conversation with the Internet itself.

Internet Telephony

See IP Telephony(g)

IP

See TCP/IP(g) district from IP (Intellectual Property)

IP

Intellectual property, as in patented technology.
See: Intellectual property rights (IPR) (g) District from IP (Internet Protocol- TCP/IP)

IP Telephony

Also known as Internet Telephony or Voice over IP (VoIP). Use of Internet Protocol (IP, see TCP/IP(g)) to carry and route two-way voice communications. IP Telephony can support telephone to telephone links through suitable adapters but also voice communications from telephone to IP terminal (such as a PC with sound card) or from IP terminal to IP terminal. The technique promises drastically reduced costs to carriers and therefore prices to end users – but it still suffers problems with quality.

IPR

Intellectual Property Rights

Tony Milbourn, Managing Director, TTP Communications Ltd., Melbourne, UK puts IPR into context: "Intellectual property is our product; in the new economy we are selling know-how and design. We need to create, develop, maintain and protect these intellectual property rights (IPR). There is a real tension here. Our customers need to be able to respond fast, to control their destiny, and to add value to their purchase in various ways. We need to avoid IPR leakage, which would devalue our product. If we are overprotective, we will never sell and the customer will never succeed. However, unless we are careful we will destroy our future business, as our IPR appears on the Internet free for all. Surely management of IPR is a critical issue in electronics companies today." See wireless ledger on investing in intellectual property (g)

IS-41

Inter-network connection protocol for connecting systems based on both analog and digital US standards. Interim standard 41

IS-54

Original TDMA(g) digital standard. Implemented in 1992 and then upgraded to the latest IS-136(g) digital standard in 1996. Interim standard 54.

IS-95/cdmaOne

In July, 1993, the Telecommunications Industry Association (TIA) (g) adopted a North American interim standard (IS-95) for second generation (2G) (g) cellular telecommunications based on Qualcomm's Narrowband CDMA technology. See the CDMA section of Qualcomm's web site for more information.

IS-136

A digital mobile telephony 3GE standard based on TDMA(g) technology. See also TDMA(g) and D-AMPS . It is also called EDGE (g).

ISDN

Integrated Services Digital Network

A fully digital telecommunications network access method which works over copper wires. There are two types of ISDN, basic rate and primary rate. Basic rate ISDN provides subscribers with two 64 kbps information channels and a single 16 kbps control channel. Primary rate provides users with thirty 64 kbps information channels and a 64 kbps control channel.

ISP

Internet Service Provider(g)

Point of access to the Internet for small business and individual users. The ISP provides its customers with dial-up access to its router which relays traffic to web servers on the Internet.

ITU (International Telecommunication Union)

An international organization under the auspices of the United Nations based in Geneca, Switzerland, is responsible for making recommendations and establishing standards governing and data communications systems for public and private. For a report on how International standards are set see standards.

Joint Detection and Interference Cancellation

An InterDigital Communications Corp. (IDCC) invention that cancels out extraneous noise. In a CDMA system everyone talks at the same time and each person is assigned a code. Envision a party where each person is using a different language to communicate. If you know the language of the person you want to speak to, you can cancel out the other languages in order to communicate with that person. See also Multiple Access(g), in particular the "cocktail party" analogy.

KHz

Kilohertz (thousands of Hertz).

LAN

Local Area Network

A LAN is a means of interconnecting computers at relatively high speed within a relatively small geographic area. Peer-to-peer LANs assign equal status to all the computers connected to them. A server-based LAN runs applications and stores data on a computer designated as the server with the other computers acting as workstations. A LAN may serve as few as a handful of users or as many as several thousand.

LEO

See MSS(g)

Local loop

A communications link (usually wire), between a telephone subscriber's location and the local telephone Central Office.

MHz

Megahertz (millions of Hertz).

MMS (Multimedia Messaging Service)

Multimedia Messaging Service is a substantial envolvment from its producer, SMS (Short Message Service) (g). Cell phone market leader Nokia (37% market share) is the major proponent of MMS. Nokia says "The Nokia MMS solution. . . The Nokia MMS solution gives mobile subscribers with MMS phones the ability to send and receive text, images, graphics and sound blended into a single rich message. MMS capable phones can also send multimedia messages directly to any e-mail address's. The Nokia Terminal Gateway makes it possible even for users of non-MMS capable legacy GSM terminals to receive multimedia messages. Legacy-terminals users receive an SMS notification and can connect to a web site to view their MMS message." Observers look for MMS to provide an attractive application for the immense capabilities of 3G (g) technology, which is beginning in some very limited markets in 2002 and expanding throughout 2003-2004. Market in Asia and Europe will be the first to experience 3GT WCDMA (g), on evolution of GSM (g), TDMA (g), GPRS (g), and EDGE (g).

Mobile system

A wireless mobile phone system or network consists of a network of cells. Each cell is served by a radio base station from where calls are forwarded to and received from your mobile phone by wireless radio signals. See FWA, fixed wireless access (g).

Modem

Modulator/Demodulator

Device which converts the digital signals from a computer into the analogue tones which are compatible with all telephone networks, and back again. For example, a modem effectively allows computers to use telephone networks for communication with other computers. Modulation techniques include a combination of AM (Amplitude Modulation), FM (frequenting Modulation), and PM (Phone Modulation), also known as PSK (phone shift keying). Techniques foster compression of signals, allowing more data to be transmitted in the same period of time.

MSS

Mobile-Satellite Service

A satellite communications system designed principally to support mobile terminals. Some MSS use Low Earth Orbit (LEO) satellite systems for their infrastructure. Each LEO satellite has the advantage of being smaller and cheaper to build and launch than geostationary satellites. And, because of their lower heights, they can be accessed more easily by mobile handsets. They can also cover parts of the world where it would otherwise be uneconomical to provide a telecommunications infrastructure. MSS operators include Globalstar, Inmarsat, ICO and Iridium.

Multi-Code Transmission

This technology allows a CDMA system to support high data- rate communications. It also makes the air interface flexible enough to provide different data rates to different mobile users on a dynamic basis. This is a fundamental feature of 3G designs and is part of the new international 3G standards. InterDigital Communications Corp. (IDCC) claims that this technology was first developed for its proprietary B-CDMA fixed wireless designs and has now been adopted as part of the standards for mobile wireless usage.

Multipath fading

The deflection of a radio signal off obstacles which can cause interference during signal reception. Multipath occurs when a radio signal is received directly by an antenna and later the same signal is received again, reflected from a building or mountain. "Ghosting" of a TV signal is a form of muiltipath. Under certain conditions, two or more of the signals can interfere with each other and create "fading" (a loss of signal) in the communications link.

Multiple Access

A methodology (FDMA, TDMA[g], CDMA) by which multiple users share access to a transmission channel. Most modern systems accomplish this through "demand assignment" where the specific parameter (frequency, time slot, or code) is automatically assigned when a subscriber requires it. See also: Bandwidth on Demand(g); Joint Detection and Interference Cancellation(g); Power Control(g); Power Ramp Up(g);

Multiplex

A stream of all the digital data carrying one or more services within a single physical channel.

Multiplexing

The simultaneous transmission of two or more signals on the same transmission medium.

Narrowband

A term applied to telecommunications facilities originally capable of carrying only voice, facsimile images, slow-scan video images and data transmissions at kilobit speeds until recently. Narrowband(g) facilities, unlike broadband facilities, could not handle full-color, full-motion video images or data transmissions at megabit speeds. The term is commonly applied to voice-grade analogue facilities and to digital facilities operating at speeds of less than 1.544 Mbps.

NMT

Nordic Mobile Telephone

One of the earliest commercial Cellular Radio(g) systems developed jointly by organization in the countries of Northern Europe, Denmark, Finland, Iceland, Norway and Sweden. It comes in two variants – NMT450 – the original specification operating in the 450 MHz band and particularly suited to covering wide areas with low usage densities – and NMT900 – introduced in the late 1980s and designed to support handheld portable devices in urban environments.

NTDD

Narrowband TDD. (See TDD) Qualcomm has made remarkable programs in developing Narrowband communication into a very high quality service comparable in my respect with wideband (g).

Open SystemC

The Open SystemC Initiative is based on an "open community licensing model," which means that the underlying source code that forms the platform of SystemC is available to the community at large, without charge. (Linux, Gnu, Apache, Netscape's Mozilla and Sun Microsystems' Jini are examples of other types of software available through similar innovative licensing models. The Open SystemC Initiative takes the best aspects of each of these models.) The idea behind open community licensing is to create some useful and valuable source code, and then publish it so that anyone can access it. When others identify bugs that they can fix or otherwise improve the source code, they can do so themselves rather than lobby the "owner" of the software or a formal standards organization for remedial patches or improvements. With hundreds or thousands of people sharing access and a common motivation to advance the quality and functionality of the source code, improvements and new capabilities can happen very quickly - far faster than could be accomplished by a single company, no matter how large. Open community licensing, then, is the opposite of the proprietary model widely favored throughout the software industry. Closed, proprietary source code models essentially say that "We own the source code. It's closed and nobody else can touch it or have any rights to improve it. You'll never see the source code, but we'd be delighted to license or sell you the object code." Open SystemC is a cooperative effort that leverages the combined technology and user experience of Synopsis, CoWare and Frontier Design. This initiative has established a modeling platform that enables, promotes and accelerates system-level CO-design and IP exchange. The SystemC community consists of a large number of system, semiconductor, IP, embedded software and EDA companies. Industry leaders committed to Open SystemC include Texas Instruments, Motorola, Lucent, Sony and CoWare
For further information on Open SystemC, see the CoWare Site's System C Section. CoWare is one of the founders of the industry coalition supporting this initiative.

OTA

Over the air (as opposed, for example, to something like synchronization within the desktop alone).

Packet Data

Information to be transmitted is broken down into digital "packages" or "packets" of bytes for more efficient use of radio spectrum. InterDigital Communications Corp. (IDCC) claims to have developed an extremely efficient way of transporting packet data over a radio system, increasing radio system capacity. InterDigital says this method is now included in the new international 3G standard as an essential part of the TDD(g) air interface Portugal. Also see: Packet Switching(g)

Packet Switching

Means of creating connections by breaking up the information to be sent into packets of bytes, sending them along a network with other information streams and reassembling the original information flow at the other end. The main advantage of packet-switching is that it makes very efficient use of fixed capacity. The disadvantage is that the quality of service of an information channel cannot be guaranteed. See also Circuit Switching(g).
InterDigital Communications Corp. (IDCC) claims to have developed an extremely efficient way of transporting packet data over a radio system, increasing radio system capacity. InterDigital says this method is now included in the new international 3G standard as an essential part of the TDD(g) air interface protocol.

The fundamental difference between a packet-based approach and a circuit-switched approach to transferring data is the concept of sharing channels. Thus, according to Lane Schaller and Jim Kamke, the move to IP is the migration from dedicated channels to shared channels. Rather than move information across one dedicated channel as circuit-based networks do, packet-based networks move it across several different nondedicated channels. Information is transmitted by squeezing packets of data into unused channel space.

For wireless carriers, using a packet-based approach is an ideal way to increase capacity. Today, because wireless transmissions are based on circuit technology, every time a user pauses when speaking, a carrier in theory is losing money because that pause could be filled by a burst of data for which the carrier could charge. However, the move to nondedicated channels also results in challenges. The biggest is that there is no longer a guaranteed data transfer pipe. Handsets must now support more complex handshakes with wireless base stations to ensure that the data is transferred correctly

Path Diversity

Motorola explains "path diversity" as follows: "With radio communications, there is usually more than one radio frequency (RF) path from the transmitter to the receiver. Therefore, multiple versions of the same signal are usually present at the receiver. However, these signals, which have arrived along different paths, are all time shifted with respect to each other because of the differences in the distance each signal has traveled. This "Multipath" effect is created when a transmitted signal is reflected off of objects in the environment (buildings, mountains, planes, trucks, etc.). These reflections, combined with the transmitted signal, create a moving pattern of signal peaks and nulls....

"When a narrow band receiver moves through these nulls there is a sudden drop in signal strength. This fading will cause either lower, more noisy speech quality or, if the fading is severe enough, the loss of signal and a dropped call. "Although Multipath is usually detrimental to an analog or TDMA signal, it is actually an advantage to CDMA, since the CDMA rake receiver can use Multipath to improve a signal. The CDMA receiver has a number of receive "fingers" which are capable of receiving the various Multipath signals. The receiver locks onto the three strongest received Multipath signals, time shifts them, and then sums them together to produce a signal that is better than any of the individual signal components. Adding the Multipath signals together enhances the signal rather than degrading it." Also see Multipath Fading(g)

PCN

Personal Communications Network

A digital wireless radiotelephone network utilizing low-powered, wireless telephones, data terminals and microcell base stations connected to the public network.

PCS

Personal Communications Service

FCC terminology describing intelligent, digital wireless, personal two-way communications via PCN.

PDC

Personal Digital Communications

TDMA(g)-based second generation Cellular Radio(g) technology originated in, and mainly used in, Japan. PDC-based services operate in the 800 MHz and 1500 MHz frequency bands.

Picocellular

A cellular system based on very small cells, typically serving users within a 20 to 250 foot radius of the base station. Also see TDD (g) which will rely heavily apon Pico cell systems.

Pilot

"Pilot" (as in "pilot code") is terminology for a signal that carries no information other than the very fact of it's existence plus the timing inherent in producing any signal. A key element of virtually every CDMA system.
Also see: global pilot channel(g)

Platform Based Design

Basically, a system on a chip (SoC) containing a "library" of hardware and software building blocks. Offered by the semiconductor industry, PBD is a silicon architecture and IP (intellectual property) with enough flexibility to offer families of products for given applications (cell phones, digital camera, etc.) PBD limits IP to certain technologies it owns r has licensed, while offering the flexibility to meet the needs of the semiconductor's customers. The best PBDs will be those that enable the greatest customer flexibility at a reasonable cost to the SoC ship maker. Platform creation requires the semi designers to concentrate first on the interfaces between the architectural components and then later on the functional blacks appropriate to the specific needs of the customer. Successful implementation of a PBD system on a chip requires years of planning and design. See Pete Hardee, "The Reality of IP Reuse"

Pilot Code (Global Pilot Channel)

A key element of virtually every CDMA system. It is a reference signal transmitted by the base station that allows reliable and robust communications by all mobile users. Now an essential part of the new international 3G standard, InterDigital Communications Corp. (IDCC) originally used this technique as part of its proprietary broadband CDMA (B-CDMA) (TM) air interface.

Power Control

A very important mechanism used in CDMA systems to control how much power is transmitted by and directed to each user. This must be precise to keep the signal clear and strong and to maximize system capacity. InterDigital Communications Corp. (IDCC) claims to have developed superior power control techniques to maximize system capacity and minimize signal interference and degradation.

Power Ramp-up (and Call Establishment)

In CDMA systems, it is critical that no one user transmit more power than is required to establish and maintain a call to avoid interference with other callers. InterDigital Communications Corp. (IDCC) claims to have invented a ramp-up scheme which is included in the new international 3G standards. It allows a user to enter a system at a low power level and increase it gradually until the call is recognized by the base station.

Processing gain

A "figure of merit" for CDMA (spread spectrum[g]) systems which relates the information data rate to the radio spectrum bandwidth. In general, the higher the processing gain, the more immune the CDMA system is to interference.

Protocol Stack

A protocol is a group of rules which determine the format of communications exchanged between the cell phone (or other device) and its user and between the devise and the base station (cell tower). Imagine using your cell phone. You push the power button, touch the number button, push the send button, then listen for ringing and an answer. The person you called says "Hello," as do you. And the conversation begins. When you do this you follow a protocol, a set of rules which enables a call to go through.

When cell phones communicate with base stations and then base to stations with other base stations, or with another cell phone, transferring voice or data, they follow a protocol. Every sound, every piece of data, every signal is specifically defined. In Wireless Communication, a photocell, then, is a highly specific group of procedures, or conversations or rules relating to how data is formatted, timed and interpreted in the air interface between the base station and the cell phone or other terminal