Chapter 1 Key Terms
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.
USB
A common way of connecting peripherals such as flash drives, Wi-Fi NICs, printers, and other peripherals to a computer. Stands for Universal Serial Bus.
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 email, play games, watch videos, and browse websites, among other functions.
wireless network interface card (wireless NIC)
A device that connects to a computer or other digital device to transmit and receive network data over radio waves. It includes an antenna for wireless communication between networked devices.
RFID reader/interrogator
A device that emits electromagnetic energy to power a typical RFID tag and can transmit to and read the data stored in the tag's memory.
wireless access point (wireless AP or just AP)
A device that receives the signals and transmits signals back to wireless network interface cards (NICs), typically in a WLAN. APs connect wireless devices to a wired network such as the Internet.
3G (third generation)
A digital cellular technology that can send data at up to 21 Mbps over the cellular network.
4G (fourth generation)
A digital cellular technology, often called LTE (Long Term Evolution), that can transmit and receive data at speeds over 20 Mbps when users are moving fast to well over 100 Mbps when users are moving slowly or are stationary.
optical fiber
A glass strand, about the thickness of a human hair, that carries data signals encoded in a laser beam.
fixed broadband wireless
A group of wireless technologies intended for communications between fixed points such as buildings or communication towers.
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 330 feet (100 meters) and has a data rate of 600 Mbps and higher. Today's WLANs are based on IEEE 802.11a/b/g/n/ac/ad standards.
Institute of Electrical and Electronic Engineers (IEEE)
A nonprofit organization that creates standards related to electrical and electronics products and devices that are adopted by manufacturers worldwide. IEEE's core purpose is to foster technological innovation and excellence for the benefit of humanity.
Wi-Fi hotspot
A public Wi-Fi network that is available at many stores, coffee shops, auto repair shops, fast-food outlets, etc., for use by its customers. Individuals can also use some smartphones to create a private Wi-Fi hotspot.
802.16 (WiMAX)
A set of standards 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 kilometers) in a point-to-point configuration. This set of standards also allows the use of both licensed and unlicensed frequencies.
piconet
A small network composed of two or more Bluetooth devices that are exchanging data with each other..
ZigBee
A specification based on IEEE 802.15.4 developed by the ZigBee Alliance, an organization that creates protocols and specifications for devices used for home automation that can wirelessly control lighting, as well as security and energy systems, in homes and industries.
WiGig
A specification for connecting computers, communication, and entertainment devices over short ranges, using the 60 GHz band at multi-gigabit speeds, developed by an alliance of companies.
radio frequency Identification (RFID)
A technology developed to replace barcodes that uses small tags placed on product packaging and boxes that an be remotely activated and read by sensors. The data about the product is then transferred directly to an information-processing system for inventory control, location tracking, and item counting.
near field communication (NFC)
A technology similar and sometimes compatible with RFID that can store data that can be used to configure and activate a connection between two devices over Bluetooth and Wi-Fi.
Voice over Internet Protocol (VoIP)
A technology that allows voice telephone calls to be carried over the same network used to carry computer data.
cable modem
A technology used to transmit data as well as video signals over a television cable connection.
digital subscriber line (DSL)
A technology used to transmit data at high speeds over a telephone line.
wireless personal area network (WPAN)
A very small network that typically extends to 33 feet (10 meters) or less. Due to its limited range, WPAN technology is used mainly as are placement for cables.See also piconet and Ultra Wide Band.
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.
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 (WiMAX) set of standards and can span an entire city, covering distances of up to 35 miles (56 kilometers) between transmitters and receivers or repeaters.
Bluetooth
A wireless standard that enables devices to transmit data at an effective rate of 721.2 Kbps over short distances of up to 33 feet (10 meters). Bluetooth is popular for short-distance communications between wireless devices such as smartphones, laptops, speakers, headsets, printers, smartwatches, and keyboards.
T1
An older wired technology used to transmit data over special telephone lines at 1.544 Mbps.
RFID tag
Device embedded in or attached to an object that contains a chip and antenna. The chip is powered by the energy emitted by an RFID reader and can then transmit information contained in its memory back to the reader.
smartwatch
Device that functions as a regular watch but also connects via Bluetooth to the owner's smartphone. Some of these devices can run applications that link directly to the same app on the smartphone, while others only display email messages, notifications, and calls from the smartphone. A few models are equipped with speakers and microphones that allow you to answer a call without having to use the smartphone and others give you the ability to respond to text messages using your voice, directly from the watch.
wireless residential gateway (often called a wireless router)
Device used to set up a Wi-Fi network in a home or small office. These devices are used to connect a home or small office to the Internet and are often supplied by the service provider, integrated with a cable modem.
wireless communications
Generally refers to any type of communications that does not require the use of wires or cables. In this sense, smoke signals and police radio may be understood as forms of wireless communications, but for the purpose of this book, wireless communications is defined as the wireless transmission of digital data while connected to some type of network.
radio module
Small radio transceiver built onto microprocessor chips and embedded into Bluetooth devices, which enable them to communicate.
link manager
Special software in Bluetooth devices that helps identify other Bluetooth devices, creates the links between them, and sends and receives data.
digital convergence
The power of digital devices such as desktop computers and wireless handhelds to combine voice, video, and data, as ell as to be connected to business and home networks and to the Internet.
