Chapter 8 Flashcards
def. wireless
Telecommunications in which electromagnetic waves carry the signal between communicating devices
What are three reasons individuals are finding wireless devices convenient and productive to use?
- people can make productive use of time that was formerly wasted (ex. public transport)
- people can take devices with them, work locations are more flexible
- enables people to schedule their working time around personal and professional obligations
What are the 3 major advantages of wireless devices to users?
- They are small enough to easily carry or wear.
- They have sufficient computing power to perform productive tasks.
- They can communicate wirelessly with the Internet and other devices
def. dematerialization
- what exhibits this?
occurs when the functions of many physical devices are included in one other physical device
-smart phones exhibit this
What is a downside of smart phones?
people can use them to copy and pass on confidential information
What are the major types of wireless media?
microwave, satellite, radio
def. microwave transmission systems
A wireless system that uses microwaves for high-volume, long-distance, point-to-point communication
what are the advantages of microwave transmission systems?
- High bandwidth
- Relatively inexpensive
def. line of sight
means that the transmitter nad receiver are in view of each other
What are some disadvantage of microwave transmissions?
- Must have unobstructed line of sight
- Susceptible to environmental interference
def. satellite transmission systems
A wireless transmission system that uses satellites for broadcast communications
What are some advantages of satellite transmission systems?
- High bandwidth
- Large coverage area
What are some disadvantages of satellite transmission systems?
- Expensive
- Must have unobstructed line of sight
- Signals experience propagation delay
- Must use encryption for security
What are the three basic types of telecommunications satellites?
- geostationary-earth-orbit (GEO),
- medium-earth-orbit (MEO),
- low-earth-orbit (LEO)
What overcomes the microwave data relay stations when speaking about satellites?
the enormous footprint—the area of Earth’s surface reached by a satellite’s transmission—overcomes the limitations of microwave data relay station
What is the most basic rule governing satellite footprint size?
The higher a satellite orbits, the larger its footprint
def. propagation delay
Any delay in communications from signal transmission time through a physical medium
Why is tracking LEO satellites more difficult than tracking MEO satellites?
they move much more quickly relative to a point on earth
What tracks satellites?
receivers
LEO satellites can pick up signals from ______ transmitters, unlike GEO and MEO satellites
weak
What are some advantages of LEO satellites?
- can pick up signals from weak transmitters. This feature makes it possible for satellite telephones to operate via LEO satellites, because they can operate with less power using smaller batteries.
- they consume less power and cost less to launch.
What is a disadvantage of LEO satellites?
footprints are small, meaning that more are needed to cover the planet
def. global positioning system (GPS)
A wireless system that uses satellites to enable users to determine their position anywhere on Earth
-supported by 24 MEO satellites
Internet over Satellite (IoS) uses what kind of satellies?
GEO
What are disadvantages if GEO satellites in terms of IoS
- involve a propagation delay
- can be disrupted by environmental influences
def. radio transmission
The use of radio-wave frequencies to send data directly between transmitters and receivers
Advantages of radio transmission?
- High bandwidth
- Signals pass through walls
- Inexpensive and easy to install
Disadvantages of radio transmission?
- Creates electrical interference problems
- Susceptible to snooping unless encrypted
- when you travel too far away from the source, the signal breaks up and fades to static
def. satellite radio (or digital radio)
A wireless system that offers uninterrupted, near CD-quality music that is beamed to your radio from satellites
ex. Sirium XM
What is the range of short-range wireless networks (in general)
30 metres or less
What are three basic short-range networks?
bluetooth, ultra-wideband, near-field communication
def. bluetooth
Chip technology that enables short-range connection (data and voice) between wireless devices
def. personal area network
A computer network used for communication among computer devices close to one person
def. ultra-wideband (UWB)
A high-bandwidth wireless technology with transmission speeds in excess of 100 Mbps that can be used for applications such as streaming multimedia from, say, a personal computer to a television
def. near-field communications (NFC)
The smallest of the short-range wireless networks that is designed to be embedded in mobile devices such as cell phones and credit cards
def. wireless local area networks (WLANs)
A computer network in a limited geographical area that uses wireless transmission for communication
What is the most common type of medium-range wireless network?
Wireless Fidelity (Wi-Fi)
def. Wireless Fidelity (or Wi-Fi)
A set of standards for wireless local area networks based on the IEEE 802.11 standard
def. wireless access point
An antenna connecting a mobile device to a wired local area network
def. hotspot
A small geographical perimeter within which a wireless access point provides service to a number of users
What are the major benefits of Wi-Fi?
- low cost
- ability to provife simple Internet access
What is the greatest facilitator of wireless internet?
-Wi-FI
What are the three factors preventing wi-fi from expanding even further?
- roaming (users have to have a different account for each wi-fi hotspot)
- security (uses radio waves, hard to shield from intruders)
- cost (hard to survive as a commercial wi-f when so many free hotspots are available to people)
What is Wi-Fi Direct?
- new generation of wi-fi
- enables peer-to-peet communications
- allows users to transfer content among devices without having to rely on a wireless antenna
- connect pairs or groups of devices at Wi-Fi speeds of up to 250 Mbps and at distances of up to 250 metres
- devices with Wi-Fi Direct can broadcast their availability to other devices just as Bluetooth devices can
- Wi-Fi Direct is compatible with the billions of Wi-Fi devices currently in use
def. MiFi
Short for mobile fidelity, it is a small, portable wireless device that provides users with a permanent Wi-Fi hotspot that they can carry along
-range is about 10 metres
What is Super Wi-Fi?
coined by the U.S. Federal Communications Commission to describe a wireless network proposal that creates long-distance wireless Internet connections
- not based on Wi-Fi technology
- uses the lower-frequency “white spaces” between broadcast TV channels. These frequencies enable the signal to travel farther and penetrate walls better than normal Wi-Fi frequencies
What two categories can wide-area wireless networks fall into?
Cellular radio and wireless broadband
def. cell phones
Phones that provide two-way radio communications over a cellular network of base stations with seamless handoffs
What are some disadvantages of 3G?
- most fundamental problem: cellular companies in North America use two separate technologies: Code Division Multiple Access (CDMA), and Global System for Mobile Communications (GSM)
- relatively expensive
What is WiMAX?
- Worldwide Interoperability for Microwave Access
- name for IEEE Standard 802.16
- wireless access range of up to 50 km, compared with 100 metres for Wi-Fi.
- WiMAX antennas can transmit broadband Internet connections to antennas on homes and businesses located miles away
- –can provide long-distance broadband wireless access to rural areas and other locations that are not currently being served
- secure system that offers features like voice and video
- facilitates image and voice transmissions, which is useful for telepresence robots
def. mobile computing
A real-time connection between a mobile device and other computing environments, such as the Internet or an intranet
What are the two major characteristics of mobile computing that differentiate it from other forms of computing?
mobility and broad reach
what does mobility refer to in mobile computing
means that users carry a device with them and can initiate a real-time contact with other systems from wherever they happen to be
what does broad reach refer to in mobile computing?
refers to the fact that when users carry an open mobile device, they can be reached instantly, even across great distances
What are the five value-added attributes that mobility and broad reach create that break the barriers of geography and time?
- ubiquity,
- convenience,
- instant connectivity,
- personalization,
- localization of products and services
describe ubiquity
A mobile device can provide information and communication regardless of the user’s location
describe convenience and instant connectivity
With an Internet-enabled mobile device, users can access the Web, intranets, and other mobile devices quickly and easily, without booting up a PC or placing a call via a modem
describe customization
A company can customize information and send it to individual consumers as a short message service (SMS)
describe localization
knowing a user’s physical location helps a company advertise its products and services
What provides the foundation for mobile commerce?
mobile computing
def. mobile commerce (m-commerce)
Electronic commerce transactions that are conducted with a mobile device
The development of m-commerce is driven by what 3 factors?
- Widespread availability of mobile devices
- Declining prices
- Bandwidth improvement
What are some of the most popular mobile commerce applications?
location-based applications, financial services, intrabusiness applications, accessing information, and telemetry
def. location-based commerce (or L-commerce)
Mobile commerce transactions targeted to individuals in specific locations, at specific times
ex. locating taxis, service personnel, doctors, and rental equipment; scheduling fleets; tracking objects such as packages and train boxcars; finding information such as navigation, weather, traffic, and room schedules; targeting advertising; and automating airport check-ins
How can location-based advertising help marketers?
make the marketing process more productive.
-Marketers can use this technology to integrate the current locations and preferences of mobile users. –They can then send user-specific advertising messages concerning nearby shops, malls, and restaurants to consumers’ wireless devices
What is the bottom line for mobile financial applications?
to make it more convenient for customers to transact business regardless of where they are or what time it is
What is happening with the growth of relatively inexpensive digital content?
growth of micropayments
-the success of micropayment applications will depend on the costs of the transactions. Transaction costs will be small only when the volume of transactions is large
def. mobile wallets (m-wallets)
A technology that allows users to make purchases with a single click from their mobile devices
where are most of today’s m-commerce applications used?
within organizations
What is another vital function of mobile technology?
to help users obtain and utilize information
What are the two types of technologies that are designed to aggregate and deliver content in a form that will work within the limited space available on mobile devices?
mobile portals and voice protals
def. mobile portal
A portal that aggregates and provides content and services for mobile users
- lean, or stripped down, version of a website that is optimized for viewing on a mobile device
- Mobile portals try to match the functionality of a website while keeping data transfers to a minimum
def. voice portal
The voice equivalent of a web portal, providing access to information through spoken commands and voice responses
def. telemetry
the wireless transmission and receipt of data gathered from remote sensors
What are some examples of telemetry’s mobile computing applications?
- technicians can use telemetry to identify maintenance problems in equipment
- doctors can monitor patients and control medical equipment from a distance
- Car manufacturers use telemetry applications for remote vehicle diagnosis and preventive maintenance
- Find My iPhone
def. the Internet of Things (IoT)
A scenario in which objects, animals, and people are provided with unique identifiers and the ability to automatically transfer data over a network without requiring human-to-human or human-to-computer interaction
what can the IoT be considered as?
invisible “everywhere computing” that is embedded in the objects around us
def. wireless sensor
an autonomous device that monitors its own condition, as well as physical and environmental conditions around it, such as temperature, sound, pressure, vibration, and movement
-can also control physical systems and it collects data
What happens when a sensor has to transmit data?
Each sensor “wakes up” or activates for a fraction of a second when it has data to transmit. It then relays those data to its nearest neighbour
T or F: every sensor transmits its data to a remote computer
F: rather than every sensor transmitting its data to a remote computer, the data travel from sensor to sensor until they reach a central computer where they are stored and analyzed
-An advantage of this process is that if one sensor fails, then another one can pick up the data. This process is efficient, is reliable, and extends battery life of the sensor
What does the information provided by wireless sensors enable?
- enables a central computer to integrate reports of the same activity from different angles within the network
- This system enables the network to determine with much greater accuracy myriad types of information such as the direction in which a person is moving, the weight of a vehicle, and the amount of rainfall over a field of crops.
def. radio-frequency identification technology (RFID)
A wireless technology that allows manufacturers to attach tags with antennas and computer chips on goods and then track their movement through radio signals
Why was RFID developed?
to replace barcodes
What are QR codes and what are their advantages over bar codes?
- two-dimensional code, readable by dedicated QR readers and camera phones
Adv:
•can store much more information.
•Data types stored in QR codes include numbers, text, URLs, and even Japanese characters.
•smaller because they store information both horizontally and vertically.
•can be read from any direction or angle, so they are less likely to be misread.
•more resistant to damage.
What are the two basic types of RFID tags?
active and passive
def. active RFID tags
use internal batteries for power, and they broadcast radio waves to a reader
-more expensive than passive RFID tags and can be read over greater distnaces
def. passive RFID tags
rely entirely on readers for their power
- less expensive than active tags, but they can be read only up to 6 metres
- usally applied to less expensive merchandise
What are some problems with RFID tags?
include expense and the comparatively large size of the tags
The IoT in smart homes
- In a smart home, your home computer, television, lighting and heating controls, home security system (including smart window and door locks), thermostats, and appliances have embedded sensors and can communicate with one another via a home network
- You control these networked objects through various devices, including your pager, smart phone, television, home computer, and even your automobile
the IoT in health care
- Patients with non-life-threatening conditions can wear sensors, or have them implanted—for example, to monitor blood pressure or glucose levels—that are monitored by medical staff.
- In many cases, the patients can be shown how to interpret the sensor data themselves
the IoT in autmotive
Modern cars have many sensors that monitor functions such as engine operation, tire pressure, fluid levels, and many others. Cars can warn drivers of impending mechanical or other problems and automatically summon roadside assistance or emergency services when necessary. Further, cars can detect vehicles in other lanes to help eliminate blind spots.
the IoT in supply chain managment
- can make a company’s supply chain much more transparent
- company can now track, in real time, the movement of raw materials and parts through the manufacturing process to finished products delivered to the customer due to sensors
the IoT in environmental monitoring
Sensors monitor air and water quality, atmospheric and soil conditions, and the movements of wildlife
the IoT in infrastructure management
Sensors monitor infrastructure such as bridges, railway tracks, and roads. They can identify and report changes in structural conditions that can compromise safety.
the IoT in energy management
- Sensors will be integrated into all forms of energy-consuming devices; for example, switches, power outlets, light bulbs, and televisions
- They will be able to communicate directly with utility companies via smart meters to balance power generation and energy usage
- Another valuable application of sensors is to use them in smart electrical meters, thereby forming a smart grid
- Smart meters monitor electricity usage, and they transmit those data in real time to the utility companies. In turn, the utilities can use these data to match power demand with production
the IoT in agriculture
Sensors monitor, in real time, air temperature, humidity, soil temperature, soil moisture, leaf wetness, atmospheric pressure, solar radiation, trunk/stem/fruit diameter, wind speed and direction, and rainfall. The data from these sensors are used in precision agriculture.
the IoT in transportation
Sensors placed on complex transportation machines such as jet engines and locomotives can provide critical information on their operations
What is the biggest challenge to wireless network management?
lack of security
-Wireless is a broadcast medium, and transmissions can be intercepted by anyone who is close enough and has access to the appropriate equipment
What are the four major threats to wireless networks?
- rogue access points,
- war driving,
- eavesdropping,
- radio-frequency jamming
def. rogue access point
an unauthorized access point to a wireless network
def. evil twin attack
- the attacker is in the vicinity with a Wi-Fi-enabled computer and a separate connection to the Internet. Using a hotspotter—a device that detects wireless networks and provides information on them the attacker simulates a wireless access point with the same wireless network name, or SSID, as the one that authorized users expect.
- If the signal is strong enough, users will connect to the attacker’s system instead of the real access point. The attacker can then serve them a web page asking for them to provide confidential information such as usernames, passwords, and account numbers. In other cases, the attacker simply captures wireless transmissions
Where are “evil twin attacks” more effective?
public hotspots
def. war driving
the act of locating WLANs while driving (or walking) around a city or elsewhere
-If a WLAN has a range that extends beyond the building in which it is located, then an unauthorized user might be able to intrude into the network. The intruder can then obtain a free Internet connection and possibly gain access to important data and other resources
def. eavesdropping
efforts by unauthorized users to access data that are travelling over wireless networks
def. radio-frequency jamming
a person or a device intentionally or unintentionally interferes with your wireless network transmissions
