BTE210 Ch 8

Satellite

+ high bandwidth + large coverage area -- expensive -- must have unobstructed line of sight -- signals experience propagation delay -- must use encryption for security

Microwave

+ high bandwidth + relatively inexpensive -- must have unobstructed line of sight -- susceptible to environmental interference

Radio

+ high bandwidth + signals pass through walls + inexpensive and easy to install -- creates electrical interference problems -- susceptible to snooping unless encrypted

IoS (Internet Over Satellite)

+ provides internet to remote parts of earth -- propagation delay -- disrupted by environment conditions

LEO

- satellites move rapidly relative to point on earth - large number needed for global coverage - requires only low-power transmitters - negligible transmission delay - least expensive to build and launch - shortest orbital life (as low as 5 years) - use telephone

MEO

- satellites move relative to point on earth - moderate number needed for global coverage - requires medium power transmitters - negligible transmission delay - less expensive to build and launch - moderate orbital life (6-12 years) - use GPS

GEO

- satellites stationary relative to point on earth - few satellites needed for global coverage -transmission delay - most expensive to build and launch - longest orbital life (many years) -use TV signal

Mi-Fi

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

Super Wi-Fi

A wireless network proposal that creates long-distance wireless Internet connections

GPS

A wireless system that utilizes satellites to enable users to determine their position anywhere on Earth, supported by MEO satellites

propagation delay

Any delay in communications from signal transmission time through a physical medium

Wi-Fi Direct

Support peer-to-peer communications similar to Bluetooth

Cellular Radio

Two-way radio communications over a cellular network of base stations with seamless handoffs

ultra-wideband

a high bandwidth wireless technology with transmission speeds in excess 100 mbps, a good choice for applications such as streaming multimedia from personal computer to TV

Wi-Fi (Wireless Fidelity)

a medium range WLAN

dematerialization

a phenomenon that occurs when the functions of many physical devices are included in one other physical device.

mobile computing

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

m-commerce

e-commerce (EC) transactions conducted with a mobile device

Near-Field Communications

has the smallest range of any short-range wireless networks, designed to be embedded in mobile devices such as cell phones and credit cards

infrared

is red light that is not commonly visible to human eyes and common applications of infrared light are found in remote control units for televisions and DVD and CD players

mobile

something that changes its location over time

WiMax

the name for IEEE Standard 802.16 which has a wireless access range of up to 31 miles and a data transfer rate of up to 75 Mbps. It is a secure system, and it offers features such as voice and video

pervasive (ubiquitous) computing

virtually every object has processing power with either wireless or wired connections to a global network

bluetooth

wireless technology designed to create small wireless networks pre-configured to do specific jobs, but not meant to replace full function networks or Wi-Fi