IS Chapters 10
-people can make productive use of time that was formerly wasted -people can take these devices with them, their work locations are becoming much more flexible -wireless technology enables people to schedule their working time around personal and professional obligations.
what are some reasons why people are switching to wireless technology
false
RFID will kill you
true
A geostationary orbit satellite (GEO) is farthest from the earth relative to the MEO and LEO.
Wireless Fidelity (Wi-Fi)
A set of standards for wireless local area networks based on the IEEE 802.11 standard.
Less power usage Less expensive picks up weak transmitters
Advantages of LEO
satellite radio
Another problem with radio transmission is that when you travel too far away from the source station, the signal breaks up and fades into static. Most radio signals can travel only 30 to 40 miles from their source. However, _________overcomes this problem. __________ (or digital radio) offers uninterrupted, near CD-quality transmission that is beamed to your radio, either at home or in your car, from space. In addition, _________ offers a broad spectrum of stations, including many types of music, news, and talk.
Bluetooth
Chip technology that enables short-range connection (data and voice) between wireless devices
1.geostationary-earth-orbit (GEO), 2. medium-earth-orbit (MEO), and 3. low-earth-orbit (LEO).
Currently, there are three types of satellites circling Earth:
No need for a PC Declining prices Bandwidth improvement All the above
Development of m-commerce is driven by
large expensive transmissions take a quarter of a second to send and return
Disadvantages of GEO satellites
-microwave transmissions offer only a limited solution to data communications needs, especially over very long distances -microwave transmissions are susceptible to environmental interference during severe weather such as heavy rain and snowstorms
Disadvantages of Microwaves
GEO LEO
Each type has a different orbit, with _____ being farthest from Earth and ______ the closest.
Congested cell phone networks
Lightradio is a possible solution to:
they are less expensive, and they do not have an appreciable propagation delay
MEO has two advantages over GEO
receivers must track the satellite
One disadvantage of MEO and LEO
expense and the comparatively large size of the tags.
Problems with RFID include:
barcodes
RFID is looked at to replace:
1. radio waves travel easily through normal office walls. 2. radio devices are fairly inexpensive and easy to install. 3. radio waves can transmit data at high speeds.
Radio transmission has several advantages:
microwave, satellite, and radio
The major types of wireless media are:
active and passive.
There are two basic types of RFID tags:
Roaming Security Cost
Three Factors Preventing Commercial Wi-Fi Market from Expanding
1. They are small enough to easily carry or wear. 2. They have sufficient computing power to perform productive tasks. 3. They can communicate wirelessly with the Internet and other devices.
Wireless devices provide three major advantages to users:
Line-of-sight
_______ means that the transmitter and receiver are in view of each other
GEO
_______ satellites are excellent for sending television programs to cable operators and for broadcasting directly to homes.
Ultra-wideband (UWB)
________ is a high-bandwidth wireless technology with transmission speeds in excess of 100 Mbps. This very high speed makes ___ a good choice for applications such as streaming multimedia from, say, a personal computer to a television.
Telemetry
________ is the wireless transmission and receipt of data gathered from remote sensors. _______ has numerous mobile computing applications. For example, technicians can use _______ to identify maintenance problems in equipment and doctors can monitor patients and control medical equipment from a distance. Car manufacturers use __________ applications for remote vehicle diagnosis and preventive maintenance. Another example is Find My IPhone
Radio-frequency identification (RFID)
________ technology allows manufacturers to attach tags with antennas and computer chips on goods and then track their movement via radio signals.
Satellite transmission systems
_________ make use of communication satellites, GEO MEO LEO
Near-field communications (NFC)
__________ has the smallest range of any short-range wireless networks. It is designed to be embedded in mobile devices such as cell phones and credit cards. For example, using ________, you can wave your device or card within a few centimeters of POS terminals to pay for items.
The global positioning system (GPS) USES MEO
__________ is a wireless system that utilizes satellites to enable users to determine their position anywhere on Earth. _______ is supported by 24 MEO satellites that are shared worldwide
Microwave transmission systems
__________ transmit data via electromagnetic waves. These systems are used for high-volume, long-distance, line-of-sight communication. Line-of-sight means that the transmitter and receiver are in view of each other. This requirement creates problems because the Earth's surface is curved rather than flat. For this reason, _________ towers usually cannot be spaced more than 30 miles apart.
passive RFID
___________ tags rely entirely on readers for their power. They are less expensive, but they can be read only up to 20 feet. For these reasons, they are generally applied to less expensive merchandise
Active RFID
___________ tags use internal batteries for power, and they broadcast radio waves to a reader. Because ________ tags contain batteries, they are more expensive tags, and they can be read over greater distances. Therefore, they are used primarily for more expensive items
Radio transmission
___________ uses radio-wave frequencies to send data directly between transmitters and receivers
Wireless media, or broadcast media
____________, transmit signals without wires
Infrared
____________is red light that is not commonly visible to human eyes and common applications of ________ are found in remote control units for televisions and DVD and CD players.
1. radio media can create electrical interference problems. 2. radio transmissions are susceptible to snooping by anyone who has similar equipment that operates on the same frequency. 3. when you travel too far away from the source station, the signal breaks up and fades into static
radio transmission has its drawbacks: