Test 2 Chapter 8

Global Positioning System

A wireless system that uses MEO satellites to enable users to determine their position anywhere on the earth. example Smartphone GPS

Internet over satellite

Allows users to access the Internet via GEO satellites from a dish mounted on the side of their homes.

Low-earth-orbit (LEO)

Are 400 to 700 miles above the surface, so they move much faster with respect to a point on the earth's surface; require many to cover the earth.

Medium-earth-orbit (MEO)

Are located 6,000 miles above the earth's surface and move; used for the GPS system.

Microwave transmission systems

Are widely used for high-volume, long-distance, point-to-point communication. Point-to-point has two characteristics: first, the transmitter and receiver must be in

Bluetooth

Can link up to eight devices within a 30-foot area and transmit up to 2.1 megabits per second.

Convenience and Instant Connectivity

Internet-enabled mobile device makes it easy and fast to access the Web, intranets, and other mobile devices without booting up a PC or placing a call.

Satellite transmission systems

Make use of communication satellites; three types of satellites, each in a different orbit:

Geostationary (GEO)

Orbits 22,300 miles directly above the equator and maintains a relatively fixed position in relation to a dish on earth; excellent for TV signals.

Infrared

Red light not visible to normal eyes - e.g., Remote

Mobile Portal

aggregates and provides content and services for mobile users that include news, sports, email, entertainment, travel and restaurant information; community services; and stock trading

Advantages of Wireless Media

are small enough to easily carry or wear, have sufficient computing power to perform productive tasks and can communicate wirelessly with the Internet and other devices

Medium-range wireless networks

are the familiar wireless local area networks (WLANs). The most common type of medium-range wireless network is Wireless Fidelity (Wi-Fi).

Wide-area wireless networks

connect users to each other and to the Internet over geographically dispersed distances.

Short-range wireless networks

generally have a range of 100 feet or less.

Ultra-wideband

high-bandwidth wireless technology with transmission speeds in excess of 100 megabits per second.

Personalization

information can be customized and sent to individual consumers (e.g., as a short message service).

Voice Portal

is a Web site with an audio interface and can also be accessed through a standard phone or cell phone.

Wi-Fi Direct

is a new iteration of Wi-Fi. Enables peer-to-peer communications, so devices can connect directly. Wi-Fi Direct enables users to transfer content among devices, even with-out a wireless antenna.

MiFi

is a small, portable, wireless device that provides users with a permanent Wi-Fi hotspot wherever they go.

Rogue access point:

is an unauthorized access point to a wireless network

Pervasive Computing (Ubiquitous computing)

is invisible "everywhere computing" that is embedded in the objects around us - the floors, the lights, our cars, washing machine, microwave oven, cell phones, clothes, and so on. (e.g., smart home, smart appliances)

War driving

is the act of locating WLANs while driving around a city or elsewhere.

Telemetry

is the wireless transmission and receipt of data gathered from remote sensors

RF (Radio frequency) jamming

is when a person or a device intentionally or unintentionally interferes with your wireless network transmissions.

Localization of products and services

knowing a user's location helps companies advertise their products and services.

Ubiquity

mobile device can provide information and communications regardless of user's location.

Eavesdropping

refers to efforts by unauthorized users to try to access data traveling over wireless networks.

Mobile computing

refers to real-time, wireless connection between a mobile device and other computing environments, such as the Internet and an intranet.

Near-field Communications

shortest range of any wireless network; designed to be embedded in mobile devices such as cell phones and credit cards.

Wireless mesh networks

use multiple Wi-Fi access points to create a wide-area networks that can be very large.

Cellular Radio

use radio waves to provide two-way communication

Wireless fidelity (Wi-Fi)

used in wireless local area networks (upto 800 feet)

Radio transmission

uses radio-wave frequencies to send data directly between transmitters and receivers