Most common type of wireless telephone communication today. It allows slow data communication, but its primary focus is voice.
Bridging standard between 2G and 3G. Digital communication allows e-mail and simple Web browsing.
3G stands for the third generation of wireless communication technology. It refers to pending improvements in wireless data and voice communications through any of a variety of proposed standards. The immediate goal is to raise transmission speeds to 2Mbit/sec.
A group of wireless specifications developed by the IEEE. It details a wireless interface between devices to manage packet traffic (to avoid collisions, etc.) Some common specifications and their distinctive attributes include the following:
- 802.11a -- Operates in the 5-GHz frequency range (5.125 to 5.85 GHz) with a maximum 54Mbit/sec. signaling rate. The 5-GHz frequency band isn't as crowded as the 2.4-GHz frequency because it offers significantly more radio channels than the 802.11b and is used by fewer applications. It has a shorter range than 802.11g, is actually newer than 802.11b and isn't compatible with 802.11b.
- 802.11b -- Operates in the 2.4-GHz Industrial, Scientific and Measurement (ISM) band (2.4 to 2.4835 GHz) and provides signaling rates of up to 11Mbit/sec. This is a very commonly used frequency. Microwave ovens, cordless phones, medical and scientific equipment, as well as Bluetooth devices, all work within the 2.4-GHz ISM band.
- 802.11e -- Ratified by the IEEE in late September of 2005, the 802.11e quality-of-service specification is designed to guarantee the quality of voice and video traffic. It will be particularly important for companies interested in using Wi-Fi phones.
- 802.11g -- Similar to 802.11b, but this standard supports signaling rates of up to 54Mbit/sec. It also operates in the heavily used 2.4-GHz ISM band but uses a different radio technology to boost overall throughput. Compatible with older 802.11b.
- 802.11i -- Also sometimes called Wi-Fi Protected Access 2 (WPA 2), 802.11i was ratified in June 2004. WPA 2 supports the 128-bit -and-above Advanced Encryption Standard, along with 802.1x authentication and key management features.
- 802.11k -- Predicted for ratification in mid-2006, the 802.11k Radio Resource Management standard will provide measurement information for access points and switches to make wireless LANs run more efficiently. It may, for example, better distribute traffic loads across access points or allow dynamic adjustments of transmission power to minimize interference.
- 802.11n -- The Standard for Enhancements for Higher Throughput is designed to raise effective WLAN throughput to more than 100Mbit/sec. Final ratification is expected in late 2006.
- 802.11r -- Expected to be ratified in mid to late 2006, the 802.11r Fast Roaming standard will address maintaining connectivity as a user moves from one access point to another. This is especially important in applications that need low latency and high quality-of-service standards such as voice-over-WLAN.
- 802.11s -- This standard will deal with mesh networking. It is predicted to be ratified in mid-2008.
A WLAN transceiver or "base station" that can connect a network to one or many wireless devices. APs can also bridge to one another. Ad hoc mode. A wireless network framework in which devices can communicate directly with one another without using an AP or a connection to a regular network. Contrasts with an infrastructure network, in which all devices communicate through an AP.
A low-cost, short-range radio link between laptops, mobile phones, network access points and other devices. Bluetooth can replace cables and can be used to create ad hoc networks and provide a standard way to connect devices anywhere in the world.
Code Division Multiple Access is a digital cellular technology that uses spread spectrum techniques that, instead of separating users by frequency, separates them through the use of digital frequency codes across the full available spectrum. Competes with GSM and TDMA.
Cellular Digital Packet Data technology is used by telecommunications carriers to transfer data to users via unused analog cellular networks. If one part of the network -- a specific geographic area or "cell" -- is overused, CDPD can automatically reallocate network resources to handle extra traffic.
The Cellular Telecommunications & Internet Association is the international organization that aims to represent all elements of wireless communication -- cellular, personal communications services, enhanced specialized mobile radio and mobile satellite services -- and serve the interests of service providers, manufacturers and others.
EDGE Enhanced Data rates for GSM Evolution -- this 3G technology allows wireless transmission of data at speeds up to 384K bit/sec. It's based on GSM technology and allows for high-bandwidth services such as multimedia. It has more support in North America than in other areas where technologies such as CDMA2000 and UMTS may be favored.
Evolution Data Only/Evolution Data Optimized is an "evolution" of CDMA networks that is based on the 1xRTT standard, providing faster wireless data transmission speeds of 400K bit/sec. to 700K bit/sec. with a theoretical peak of 2.4M bit/sec. Verizon Wireless and Sprint Corp. in the U.S. were rolling out the service in early 2005, connecting to laptops via a plug-in card.
Flash-OFDM is a proprietary cellular broadband technology that network operators can deploy either for notebook computers of mobile users or serve as a fixed wireless access system, bridging the "last mile" to connect computers in homes and small offices. Key features include an all-IP architecture and fast speeds. The technology is capable of letting users traveling at 250 kilometers per hour to download data at speeds up to 1.5Mbit/sec. or upload at speeds up to 500Kbit/sec. Orthogonal Frequency Division Multiplexing (OFDM) works by splitting radio signals into smaller low-speed signals that are transmitted in parallel, reducing crosstalk and using bandwidth efficiently, but decreasing range.
The Global Positioning System is a "constellation" of 24 satellites that orbit the Earth at a height of 10,900 miles, making it possible for people using ground receivers to determine their geographic location within 10 to 100 meters. The satellites use simple mathematical calculations to broadcast information that is translated as longitude, latitude and altitude by Earth-based receivers.
General Packet Radio Service technology runs at speeds up to 115Kbit/sec., compared with the 9.6Kbit/sec. of older GSM systems. It enables high-speed wireless Internet and other communications such as e-mail, games and applications. It supports a wide range of bandwidths and is an efficient use of limited bandwidth. It's particularly suited for sending and receiving small amounts of data, such as e-mail and Web browsing, as well as large volumes of data.
Global System for Mobile Communications is a digital cellular system based on TDMA narrowband technology, which gives users access to time slots on the same frequency bands. It allows up to eight simultaneous communications on the same frequency. It competes with CDMA.
High-Speed Downlink Packet Access is a 3G high-speed data technology that is an improvement to the WCDMA standard. It boosts speed and reduces latency. It operates in the 5MHz spectrum and will initially provide real-world speeds of 400K bit/sec. to 600K bit/sec., with theoretical peak speeds of 14.4M bit/sec.
A place, such as a hotel, restaurant or airport, that offers Wi-Fi access, either free or for a fee.
A popular wireless Internet service rolled out in 1999 by NTT DoCoMo Inc. in Japan. It's based on a simplified form of HTML and delivers packet-based information -- such as games, e-mail and even business applications -- to handheld devices.
Institute of Electrical and Electronics Engineers Inc. is a nonprofit, technical professional association of more than 360,000 individual members in approximately 175 countries that is an authority in technical areas such as computer engineering and telecommunications. It developed the 802.11 specifications.
Every wireless 802.11 device has its own specific Media Access Control address hard-coded into it. This unique identifier can be used to provide security for wireless networks. When a network uses a MAC table, only the 802.11 radios that have had their MAC addresses added to that network's MAC table are able to get onto the network.
Mesh networking features freestanding, non-wired network nodes that communicate among one another and form self-configuring networks, with only one node required to hook into a wired LAN. The other nodes are simply plugged in to an electrical outlet, so cabling is much less of an issue.
Multiple Input Multiple Output refers to using multiple antennas in a WiFi device to improve performance and throughput. The MIMO technology takes advantage of a characteristic called multipath, which occurs when a radio transmission starts out at point A and then reflects off or passes through surfaces or objects before arriving, via multiple paths, at point B. MIMO technology uses multiple antennas to collect and organize signals arriving via these paths. The technology is expected to be used in the 802.11n standard.
Radio frequency identification uses low-powered radio transmitters to read data stored in a transponder (tag) at distances ranging from one inch to 100 feet. RFID tags are used to track assets, manage inventory and authorize payments, and they increasingly serve as electronic keys for everything from autos to secure facilities.
Movement of a mobile device from one wireless network location to another without interruption in service or loss in connectivity.
A wireless phone with text and Internet capabilities. Smart phones can handle wireless phone calls, hold addresses and take voice mail and can also access information on the Internet and send and receive e-mail and fax transmissions.
Done at the location for a new WLAN in an effort to avoid what could be time-consuming and costly problems down the road. It involves diagramming the network, checking the building and testing the equipment.
Short Message Service allows the transmission of short text messages among mobile devices such as cell phones, fax machines and BlackBerry devices. Messages -- up to 160 alphanumeric characters but not containing images or graphics -- appear as text on the display screen of the receiving device. It works with GSM networks.
A Service Set Identifier is a sequence of characters unique to a specific network or network segment that's used by the network and all attached devices to identify themselves and allow devices to connect to the correct network when more than one independent network is operating in nearby areas.
A joint venture among LM Ericsson Telephone Co., Motorola Inc., Nokia Corp. and Psion PLC to develop new operating systems based on Psion's EPOC32 platform for small mobile devices for wireless devices such as phones and handhelds.
Time Division Multiple Access divides a radio frequency available to a network into time slots and then allocates slots to multiple calls. So one frequency can support multiple, simultaneous data channels, using bandwidth more efficiently than earlier technologies. Available in 800-MHz or 1900-MHz frequencies, TDMA is used by the GSM digital cellular system.
Universal Mobile Telecommunications System, is a 3G cellular network technology that uses WCDMA (Wideband Code Division Multiple Access), which was operating in 25 countries as of mid-2005. The transmission rates range from a theoretical 384K bit/sec. for phones that are moving up to 2M bit/sec. for stationary devices.
Ultrawideband, also called digital pulse, is a wireless technology for transmitting digital data over a wide swath of the radio frequency spectrum with very low power. Because of the low power requirement, it can carry signals through doors and other obstacles that tend to reflect signals at more limited bandwidths and a higher power. It can carry large amounts of data and is used for ground-penetrating radar and radio locations systems.
Voice over Internet Protocol is a system for delivering digitized voice communications across IP networks. VOIP technology allows phone calls to be made between compatible handsets or on computers with appropriate software.
The Wireless Application Protocol is a set of specifications, developed by the WAP Forum, that lets developers using Wireless Markup Language build networked applications designed for handheld wireless devices. WAP was designed to work within the constraints of these devices: a limited memory and CPU size, small, monochrome screens, low bandwidth and erratic connections. WAP is a de facto standard, with support from more than 200 vendors.
Wideband Code Division Multiple Access is a 3G wireless technology derived from CDMA that transmits digitized data over a wide range of frequencies to boost speed. It uses wide 5 MHz channels and is associated with UMTS and GSM, where it boosts speed by substituting TDMA technology for CDMA. It's used for voice, data and video services and can achieve data rates up to 2M bit/sec.
Wired-Equivalent Privacy protocol was specified in the IEEE 802.11 standard to provide a WLAN with a minimal level of security and privacy comparable to a typical wired LAN, using data encryption. It's now widely recognized as flawed because of an insufficient key length and other problems and can be cracked in a short time with readily available tools.
Wireless Multimedia Extensions (WME) -- also known as Wireless Multimedia Enhancement or Wi-Fi Multimedia (WMM) -- is a set of features based on the IEEE 802.11e draft standard that provide basic Quality of service (QoS) features to IEEE 802.11 networks. It prioritizes traffic from different applications such as voice, audio and video applications under different environment and conditions. Traffic priority is based on four access categories, listed here in their order of importance: voice, video, best effort (Web surfing and e-mail, for example) and background (applications not dependent upon latency, such as printing).
Wi-Fi Protected Access is a data encryption specification for 802.11 wireless networks that replaces the weaker WEP. Created by the WiFi Alliance before a 802.11i security standard was ratified by the IEEE, it improves on WEP by using dynamic keys, Extensible Authentication Protocol to secure network access, and an encryption method called Temporal Key Integrity Protocol (TKIP) to secure data transmissions.
Wi-Fi Protected Access 2 is an enhanced version of WPA. It is the official 802.11i standard that was ratified by the IEEE in June 2004. It uses Advanced Encryption Standard instead of TKIP (see above). AES supports 128-bit, 192-bit and 256-bit keys.
Wireless fidelity is the generic term for 802.11 technology (see 802.11 above).
Wireless local-area networks use radio waves instead of a cable to connect a user device, such as a laptop computer, to a LAN. They provide Ethernet connections over the air and operate under the 802.11 family of specifications developed by the IEEE.
Typically refers to driving around with a wireless-enabled laptop and antenna to find places where it's possible to access exposed wireless networks. These are usually company networks that extend beyond the physical infrastructure of the company and are left unprotected.
Marking buildings or sidewalks with chalk to show others where it's possible to access an exposed company wireless network. These access points are typically found through war driving (see above).
Popular name of the 802.16 wireless metropolitan-area network standard that's currently being developed. WiMax, which will have a range of up to 31 miles, is primarily aimed at making broadband network access widely available without the expense of stringing wires (as in cable-access broadband) or the distance limitations of Digital Subscriber Line. There are two flavors of WiMax: 802.16-2004 or 802.16d, for fixed implementations, and 802.16e, for mobile service.
Wireless Markup Language is like the Internet programming language HTML. It delivers Internet content to small wireless devices, such as browser-equipped cellular phones and handheld devices, which typically have very small displays, slow CPUs, limited memory capacity, low bandwidth and restricted user-input capabilities.
A nonprofit international association formed in 1999 to certify interoperability of WLAN products based on the IEEE 802.11 specification. Currently, the Wi-Fi Alliance has over 200 member companies from around the world, and over 1,000 products have received Wi-Fi certification since certification began in March of 2000. The goal of the Wi-Fi Alliance's members is to enhance the user experience through product interoperability.
For more, read WIRELESS CUTS LOOSE, Computerworld May 10 issue pages 24, 25