Wireless CH1

wireless communications

The transmission of user data between devices without the use of wires.

3G (third generation)

A digital cellular technology that can send data at up to 21 Mbps over the cellular telephone network.

personal digital assistant (PDA)

A handheld computer device used for taking notes, making appointments, creating to-do lists, and communicating with other devices.

motes

Remote sensors used for collecting data from manufacturing equipment or for scientific research, which can communicate using wireless technology.

link manager

Special software in Bluetooth devices that helps identify other Bluetooth devices, creates the links between them, and sends and receives data.

digital subscriber line (DSL)

A technology used to transmit data over a telephone line. Hypertext Markup Language (HTML) The standard language for displaying Web pages.

cable modem

A technology used to transmit data over a television cable connection.

J2ME (Java 2 Micro Edition)

A variation of the Java programming language designed for use in portable devices such as PDAs and cellular phones.

Ultra Wide Band (UWB)

A wireless communications technology that allows devices to transmit data at hundreds of megabits or even gigabits per second at short distances—up to 6 feet (2 meters) at the higher speeds and up to 150 feet (50 meters) at lower speeds.

Bluetooth

A wireless standard that enables devices to transmit data at up to 721.2 Kbps over a typical maximum distance of 33 feet. Bluetooth can transmit data farther, but devices that can use this capability are rare.

WiGig

An alliance of companies involved in developing a common wireless specification for connecting computers, communication, and entertainment devices over short ranges, using the 60 GHz band at multi-gigabit speeds.

ZigBee Alliance

An organization that creates protocols and specifications for devices used to wirelessly control lighting, as well as security and energy systems, for home and industry.

satellite radio

A pay-for-service radio broadcast system that transmits digital programming directly from satellites to a network of ground-based repeaters and that holds the signal regardless of the listener's location. Users must purchase special receivers and pay a monthly subscription fee to listen to commercial-free music channels. Because the digital transmission is decoded at the receivers, the sound quality is also much better than conventional FM radio.

piconet

A small network composed of two or more Bluetooth devices that are exchanging data with each other.

wireless metropolitan area network (WMAN)

A wireless network that covers a large geographical area such as a city or suburb. The technology is usually based on the IEEE 802.16 set of standards and can span an entire city, covering distances of up to 35 miles (56 km) between transmitters and receivers or repeaters.

wireless wide area network (WWAN)

A WAN that uses cellular phone technologies and encompasses any geographical region, including the entire globe.

Wi-Fi

A certification label awarded to IEEE 802.11 WLAN-compatible wireless devices that pass all interoperability tests performed by an organization called the Wi-Fi Alliance. The acronym is often thought to stand for Wireless Fidelity, but this is a common misconception. The name was chosen by the alliance purely for marketing reasons and is not an acronym at all.

repeater

A device commonly used in satellite communications that simply "repeats" the signal to another location.

smartphone

A device that combines a cellular phone with the capabilities of a personal digital assistant (PDA). These devices provide the user with the ability to enter appointments in a calendar, write notes, send and receive e-mail, and browse Web sites, among other functions.

wireless network interface card (wireless NIC)

A device that connects to a PC to transmit and receive network data over radio waves. It includes an antenna for wireless communication between networked devices.

access point (AP or wireless AP)

A device that receives the signals and transmits signals back to wireless network interface cards (NICs).

4G (fourth generation)

A digital cellular technology that can transmit and receive data at theoretical speeds up to 20 Mbps when users are moving fast and up to 150 Mbps (theoretically) when users are moving slowly or are stationary.

optical fiber

A glass strand, about the thickness of a human hair, that carriers data signals encoded in a laser beam.

wireless local area network (WLAN)

A local area network that is not connected by wires but instead uses wireless technology. Its range extends to approximately 100 meters and has a maximum data rate of 600 Mbps. Today's WLANs are based on IEEE 802.11a/b/g/n standards.

Institute of Electrical and Electronic Engineers (IEEE) 802.11n-2009

A set of standards that allows WLAN computers to transmit data at speeds ranging from 1 Mbps to a maximum of 600 Mbps. 802.11n (or 802.11n-2009, as the specification is now called) can also make use of the 5 GHz band in addition to the 24 GHz band.

Institute of Electrical and Electronic Engineers (IEEE) 802.16 Fixed Broadband Wireless

A set of standards, some established and some still under development, for fixed and mobile broadband wireless communications that allows computers to communicate at up to 75 Mbps and at distances of up to 35 miles (56 km) in a point-to-point configuration. This set of standards also allows the use of both licensed and unlicensed frequencies.

radio frequency identification (RFID)

A small tag placed on product packaging and boxes that can be remotely activated and read by remote sensors. The data about the product is then transferred directly to an information-processing system for inventory control, location tracking, and item counting.

WirelessHD

A specification for the wireless transmission of high-definition video (HD), multichannel audio and data between consumer devices such as televisions, stereo systems, and Blu-ray players, using the 60 GHz frequency band.

Wireless Application Protocol (WAP or WAP2)

A standard for transmitting, formatting, and displaying Internet data on cellular phones. WAP can display only text. WAP2 supports HTML and can display color and pictures.

Voice over Internet Protocol (VoIP)

A technology that allows voice telephone calls to be carried over the same network used to carry computer data.

Integrated Services Digital Networks (ISDN)

A technology that transmits data over telephone lines at a maximum of 256 Kbps.

T1

A technology used to transmit data over special telephone lines at 1.544 Mbps.

microbrowser

A tiny browser program that runs on a WAP or WAP2 cellular phone.

wireless personal area network (WPAN)

A very small network that typically extends to 10 meters or less. Due to its limited range, WPAN technology is used mainly as a replacement for cables. See also piconet and Ultra Wide Band.

radio modules

Small radio transceivers built onto microprocessor chips and embedded into Bluetooth devices, which enable them to communicate.

digital convergence

The power of digital devices such as desktop computers and wireless 1 handhelds to combine voice, video, and text-processing capabilities as well as to be connected to business and home networks and to the Internet.