Glossary

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2G

The second generation of cellular systems. 2G systems use digital encoding. 2G networks support high bit rate voice, limited data communications, and different levels of encryption. 2G networks utilize either GSM, TDMA or CDMA technology. Note that 2G networks were the first cellular networks capable of supporting short message service (SMS) applications.

2.5G

New hybrid "always on" cellular networks such as GSM/GPRS and cdmaOne. 2.5G networks can transfer data at speeds of up to 144 Kbps (faster than traditional 2G digital networks, but slower than true 3G networks). A phone with 2.5G services can alternate between using the Web, sending or receiving text messages, and making phone calls without losing its connection. 2.5G networks actually extend existing 2G systems by adding features such as packet-switched connection and enhanced data rates. These networks also support the Wireless Application Protocol (WAP), multimedia messaging service (MMS), short message service (SMS), mobile games, and more.

2.75G

Typically refers to either an EDGE cellular network because it supports both more and better quality voice and faster data transfers via GPRS or a cdma2000 1X network because it can double the voice capacity of cdmaOne networks and delivers peak packet data speeds of 307 Kbps in mobile environments.

3G

The third generation of mobile systems. 3G systems provide high-speed data transmissions of 144 Kbps and higher. 3G networks should be able to support multimedia applications such as full-motion video, video conferencing and Internet access. Technologies touted as 3G include Wideband CDMA (commonly known as W-CDMA) and cdma2000 1xEV-DV (Data Voice) because both can provide integrated voice and simultaneous high-speed packet data multimedia services at speeds that have tested as high as 3.09 Mbps.

3G/UMTS (Third Generation/Universal Mobile Telecommunications System)

See W-CDMA.

A

AAA (Authentication, Authorization, and Accounting)

A term for a framework that enables intelligent access control to computer resources by enforcing policies, auditing usage, and providing the information necessary to bill for services. AAA is typically provided via a suite of network security services.

Access Point (AP)

A transmitting device that acts as a wireless hub and typically interfaces between a wireless network and a wired network. Access points combined with a distribution system (e.g. Ethernet) support the creation of multiple radio cells (basic service sets) that enable roaming. Sometimes referred to as a "Base Station."

Access Controller

A device that provides centralized intelligence behind a wireless LAN's access points so as to regulate traffic between a wireless LAN and other network resources. An access controller typically resides on the wired portion of a network between the wireless network's access points and the protected side of a wired network.

Ad Hoc Network

A wireless network composed of only stations (computing devices) and no access point. Also referred to as an "Independent Basic Service Set."

See also Basic Service Set (BSS).

ADSL

See Asymmetric Digital Subscriber Line (ADSL).

Advanced Encryption Standard (AES)

A symmetric 128-bit block data encryption technique developed by Belgian cryptographers, Joan Daemen and Vincent Rijmen. The U.S government adopted the algorithm as its encryption technique in October 2000, as a replacement for the outdated DES encryption.

AES

See Advanced Encryption Standard (AES).

AGC

See Automatic Gain Control (AGC).

Aggregator

A term that is used to describe a group of virtual network wholesalers that help to tie individual HotSpots networks into a larger, cohesive roaming network. Other terms for the aggregator group are "Virtual WISPs" as most do not really have an actual physical network; "brokers," since they broker deals between companies within the WISP Industry; and "managed service providers," since their business model is based upon managing Internet access service for others. An aggregator typically provides centralized authentication services in order to compute and validate traffic; fix the airtime prices in which they trade; operate as intermediaries between HotSpot operators through buying and selling airtime minutes; and fix the tariffs for roaming between HotSpot operator networks.

AM

See Amplitude Modulation (AM).

American National Standards Institute (ANSI)

A private non-profit membership organization founded in 1918. ANSI coordinates (within the U.S.) the voluntary standard system that brings together interests from the private and public sectors to develop voluntary standards for a wide array of U.S. industries. ANSI develops and publishes standards for transmission codes, protocols and high-level languages used in the telecommunications industry.

Amplitude Modulation (AM)

This refers to a method of signal modulation in which the amplitude of the carrier voltage is carried in proportion to the changing frequency value of an applied voltage. AM impresses data onto an alternating-current (AC) carrier waveform. The highest frequency of the modulating data is normally less than 10 percent of the carrier frequency. The instantaneous amplitude (overall signal power) varies depending on the instantaneous amplitude of the modulating data.

ANSI

See American National Standards Institute (ANSI).

AP

See Access Point (AP).

AppleTalk

A proprietary set of local area network protocols developed by Apple for its Macintosh processors. An AppleTalk network supports up to 32 devices and data can be exchanged at a speed of 230 Kbps. AppleTalk's Datagram Delivery Protocol corresponds closely to the Network layer of the Open Systems Interconnection (OSI) communication model.

ASCII (American Standard Code for Information Interchange)

A standard developed by the American National Standards Institute (ANSI) to define how computers write and read characters. The ASCII set of 128 characters includes letters, numbers, punctuation, and control codes (such as a character that marks the end of a line). Each letter or other character is represented by a number: an uppercase A, for example, is the number 65, and a lowercase z is the number 122. Most operating systems use the ASCII standard, except for Windows NT, which uses the suitably larger and newer Unicode standard.

Asymmetric Digital Subscriber Line (ADSL)

A method for getting reasonably high data rates (around 1 Mbps) using the existing telephone twisted pair wiring by using spare capacity not needed for voice traffic. The asymmetric simply refers to the different data rates provided upstream and downstream.

Automatic Gain Control (AGC)

A process or means by which gain is automatically adjusted in a specified manner as a function of a specified parameter, such as received signal level.

Automatic Identification and Data Collection (AIDC)

A term that refers to the direct entry of data into a computer system, programmable logic controller (PLC) or other microprocessor-controlled device without using a keyboard. AIDC technologies provide a reliable means not only to identify but also to track items. It is possible to encode a wide range of information, from basic identification to comprehensive details about the item or person. AIDC includes a number of technologies, which provide different solutions to data collection problems. These include: barcode, radio frequency identification (RFID), magnetic stripes, voice and vision systems, optical character recognition (OCR), biometrics, as well as others.

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