3G (third generation): An industry term used to describe the next generation of wireless applications. It represents a move from circuit-switched communications (where a device user has to dial in to a network) to broadband, high-speed, packet-based wireless networks (which are “always on”).

802.11: A family of wireless specifications developed by a working group of The Institute of Electrical and Electronics Engineers. These specifications are used to manage packet traffic over a network and ensure that packets do not collide—which could result in loss of data—while traveling from their point of origin to their destination (that is, from device to device).

AMPS (advanced mobile phone service): A term used for analog technologies, the first generation of wireless technologies.

Analog: Radio signals that are converted into a format that allows them to carry data. While cell phones and other wireless devices still use analog in geographic areas where there is little or no coverage by digital networks, analog will eventually give way to faster digital networks, analysts say.

Bandwidth: The size of a network “pipe” or channel for communications in wired networks. In wireless, it refers to the range of available frequencies that can carry a signal.

Blackberry: Two-way wireless device, made by Waterloo, Ontario-based Research in Motion, that allows users to check e-mail and voice mail (translated into text), as well as page other users via a wireless network service. Also known as a RIM device, it has a miniature QWERTY keyboard for users to type their messages. It uses the SMS protocol (see SMS ). Blackberry users must subscribe to a wireless service that allows for data transmission.

Bluetooth: A short-range wireless specification that allows for radio connections between devices within a 30-foot range of each other. The name comes from 10th-century Danish King Harald Blåtand (Bluetooth), who unified Denmark and Norway.

CDMA (code division multiple access): U.S. wireless carriers, such as Sprint PCS and Verizon, use CDMA to allocate bandwidth for users of digital wireless devices. CDMA distinguishes between multiple transmissions carried simultaneously on a single wireless signal. It carries the transmissions on that signal, freeing network room for the wireless carrier and providing interference-free calls for the user.

CDPD (cellular digital packet data): Telecommunications companies can use CDPD to transfer data on unused cellular networks to users. If one section, or “cell,” of the network is overtaxed, CDPD automatically allows for the reallocation of resources.

Cellular: Technology that sends analog or digital transmissions from transmitters that have areas of coverage called cells. As a user of a cell phone moves between transmitters from one cell to another, the user’s call travels from transmitter to transmitter uninterrupted.

Circuit switched: Used by wireless carriers, this method lets a user connect to a network or the Internet by dialing in, such as with a traditional phone line. It’s a dial-in ISP for wireless device users. Circuit-switched connections can be slow and unreliable compared with packet-switched networks, but for now circuit-switched networks are the primary methods of Internet and network access for wireless users in the United States (see Packet-switched network ).

Dual-band mobile phone: Phones that support both analog and digital technologies by picking up analog signals when digital signals fade. Most mobile phones are not dual-band.

EDGE (enhanced data GSM environment): A faster version of the GSM standard. It is faster than GSM because it can carry messages using broadband networks that employ more bandwidth than standard GSM networks (see GSM ).

EV-DO or 1xEV-DO (1x Evolution-Data Optimized): A wireless radio broadband data standard adopted by many CDMA mobile phone service providers in Asia-Pacific, Europe, North America, and South America. It is standardized by 3GPP2, as part of the CDMA family of standards. It is commonly referred in the industry as DO ("Dee-Oh").

FDMA (frequency division multiple access): An analog standard that lets multiple users access a group of radio frequency bands and eliminates interference of message traffic.

Frequency hopping spread spectrum: A method by which a carrier spreads out packets of information (voice or data) over different frequencies. For example, a phone call is carried on several different frequencies so that when one frequency is lost another picks up the call without breaking the connection.

GPRS (general packet radio service): A technology that sends packets of data across a wireless network at speeds of up to 114Kbps. It is a step up from the circuit-switched method; wireless users do not have to dial in to networks to download information. With GPRS, wireless devices are always on—they can receive and send information without dial-ins. GPRS is designed to work with GSM.

GSM (global system for mobile communications): A standard for how data is coded and transferred through the wireless spectrum. The European wireless standard also used in Asia, GSM is an alternative to CDMA. GSM digitizes and compresses data and sends it down a channel with two other streams of user data. The standard is based on time division multiple access (see TDMA ).

HDML (handheld device markup language): It uses hypertext transfer protocol (HTTP, the underlying protocol for the Web) to allow for the display of text versions of web pages on wireless devices. Unlike wireless markup language (see WML ), HDML is not based on XML. HDML also does not allow developers to use scripts, while WML employs its own version of JavaScript.

HSDPA (High-Speed Downlink Packet Access): A mobile telephony protocol that is a 3G technology and provides a smooth evolutionary path for UMTS-based 3G networks allowing for higher data transfer speeds. An evolution of the W-CDMA standard, HSDPA achieves the increase in the data transfer speeds by defining a new W-CDMA channel: a high-speed downlink shared channel (HS-DSCH) that operates in a different way from existing W-CDMA channels and is used for downlink communications to the mobile.

I-Mode: A wildly popular service in Japan for transferring packet-based data to handheld devices. I-Mode is based on a compact version of HTML and does not use WAP (see WAP ), setting it apart from other widely used transmission methods.

iDEN (Integrated Digital Enhanced Network): A technology that allows users to access phone calls, two-way radio transmissions, paging and data transmissions from one wireless device. Developed by Motorola, iDEN is based on TDMA.

Kbps (kilobits per second): A measurement of bandwidth in the United States.

Packet: A chunk of data that is sent over a network, whether it’s the Internet or wireless network. Packet data is the basis for packet-switched networks, which are a more reliable method of transferring wireless data than a circuit-switched network. Packet-switched networks eliminate the need to dial in to send or receive information because they are “always on,” transferring data without the need to dial. The packets that hold data depend on the size of the data involved; “chunks” are broken down into an efficient size for routing. Each of these packets has a separate number and carries the Internet address for which it is destined.

PCS (personal communications services): An alternative to cellular, PCS works like cellular technology because it sends calls from transmitter to transmitter as a caller moves. But PCS uses its own network, not a cellular network, and offers fewer “blind spots”—areas in which access to calls is not available—than cellular. PCS transmitters are generally closer together than their cellular counterparts.

PDA (personal digital assistant): Mobile , handheld devices—such as the TOUGH-PC TDA R1000 Series —that give users access to text-based information. Users can synchronize their PDAs (or TDAs) with a PC or network; some models support wireless communication to retrieve and send e-mail and get information from the Web.

Radio frequency devices: These devices use radio frequencies to transmit data. One typical use: a bar code scanner gathers information about products in stock or ready for shipment in a warehouse or distribution center and sends them to a database or ERP system.

Satellite phone: Phones that connect callers via satellite. The idea behind a satellite phone is to give users a worldwide alternative to sometimes unreliable digital and analog connections. So far, such services have proven very costly and have appealed to few users aside from, for example, the crews at deep-sea oil rigs with phones configured to connect to a satellite service.

Smart phone: A combination of a mobile phone and a PDA, smart phones allow users to converse as well as perform tasks, such as accessing the Internet wirelessly and storing contacts in databases. Smart phones have a PDA-like screen. As smart phone technology matures, some analysts expect these devices to prevail among wireless users. A PDA equipped with an Internet connection could be considered a smart phone. Ericsson, Nokia and Motorola also make smart phones.

SMS (short messaging service): A service through which users can send text-based messages from one device to another (see Blackberry ). The message—up to 160 characters—appears on the screen of the receiving device. SMS works with GSM networks.

TDMA (time division multiple access): This protocol allows large numbers of users to access one radio frequency by allocating time slots for use to multiple voice or data calls. TDMA breaks down data transmission, such as a phone conversation, into fragments and transmits each fragment in a short burst, assigning each fragment a time slot. With a cell phone, the caller would not detect this fragmentation. Whereas CDMA (which is used more frequently in the United States) breaks down calls on a signal by codes, TDMA breaks them down by time. The result in both cases: increased network capacity for the wireless carrier and a lack of interference for the caller. TDMA works with GSM and digital cellular services.

WAP (wireless application protocol): WAP is a set of protocols that lets users of mobile phones and other digital wireless devices access Internet content, check voice mail and e-mail, receive text of faxes, and conduct transactions. WAP works with multiple standards, including CDMA and GSM.

WASP (wireless application service provider): These vendors provide hosted wireless applications so that companies will not have to build their own sophisticated wireless infrastructures. Vendors include Etrieve and Wireless Knowledge.

WCDMA (wideband CDMA): A third-generation wireless technology under development that allows for high-speed, high-quality data transmission. Derived from CDMA, WCDMA digitizes and transmits wireless data over a broad range of frequencies. It requires more bandwidth than CDMA but offers faster transmission because it optimizes the use of multiple wireless signals—not just one, as with CDMA.

Wi-Fi (shorthand for “wireless fidelity”): Is the common term for a high-frequency wireless local-area network (WLAN). The term is used generically when referring of any type of 802.11 network, whether 802.11b, 802.11a, dual-band and so on. Wi-Fi operates in the 2.4GHz range offering data speeds up to 11 Mbps. Wi-Fi is gaining acceptance as an alternative to a wired WLAN in companies and multi-computer homes. Unless protected, a Wi-Fi wireless WLAN can be susceptible to access from the outside by unauthorized user seeking to access the Internet for free. Locating and exploiting security-exposed WLANs is called war driving.

Warchalking is the term for the markings used to indicate where an exposed WLAN is accessible. Companies can safeguard these networks using the wired equivalent privacy (WEP) encryption standard, a virtual private network and other options.

Wireless LAN: It uses radio frequency technology to transmit network messages through the air for relatively short distances, like across an office building or college campus. A wireless LAN can serve as a replacement for or extension to a wired LAN.

Wireless spectrum: A band of frequencies where wireless signals travel carrying voice and data information. Wireless carriers are bidding at Federal Communications Commission auctions on slivers of airwaves through which they will ultimately be able to send third-generation communications.

WISP (wireless Internet service provider): A vendor that specializes in providing wireless Internet access.

WML (wireless markup language): A version of HDML, WML is based on XML and will run with its own version of JavaScript. Wireless application developers use WML to repurpose content for wireless devices.