CH08 - Wireless, mobile computing and mobile commerce Flashcards
Definition for Wireless Devices
- Small enough to easily carry or wear
- Have sufficient computing power to perform productive tasks.
- They can communicate wirelessly with the Internet and other devices.
The distinctions between Wireless and Mobile
- Wireless: without wires-cables and via electromagnetic waves.
- Mobile: something that changes its location over time.
- A technology (device or transmission media) can be wireless and not be mobile (e.g., antenna)
What’s dematerialization? (IMPORTANT)
Using less to produce more
Smart phones are an example of dematerialization: functions of many devices are included in one physical device [so some of the devices “disappear”]
What are the Wireless Transmission Systems/Broadcast medias?
- Microwave transmission systems
- Satellite transmission systems
- Radio transmission systems
What’s a Microwave Transmission System?
- These systems transmit data via electromagnetic waves
- We use them for high-volume, long-distance, line-of-sight communication
- Earth’s surface is curved so we place them on high lands
→ AKA the straight path between a transmitting antenna
What’s a Satellite Transmission System?
- Satellite transmission uses satellite to transmit signals without wires
- Can be used for GPS system, Internet over Satellite, and Commercial Imaging among other applications
- Require direct line-of-site and have a large footprint
- Use broadcast transmission, sending signal to many receivers at once
- Con: The transmission delay can be large (Distance form Earth), Costly
What’s a Satellite Transmission System?
- Satellite transmission uses satellite to transmit signals without wires
- Can be used for GPS system, Internet over Satellite, and Commercial Imaging among other applications
- Require direct line-of-site and have a large footprint
- Use broadcast transmission, sending signal to many receivers at once
- Con: The transmission delay can be large (Distance form Earth), Costly
What’s a Radio Transmission System?
- Radio transmission uses radio-wave frequencies to send data directly between transmitters and receivers.
- Radio waves travel easily through normal office walls.
- Radio devices are fairly inexpensive and easy to install.
- Radio waves can transmit data at high speeds.
- Wi-Fi and cellular also use radio-wave frequencies.
What are the 3 basic types of telecommunication satellites?
- GEO
- MEO
- LEO
The higher the satellite orbits, the higher is footprint.
What are the characteristics of a GEO satellite?
Orbit: 35.900 km
Use: TV signal
- Satellites stationary relative to point on Earth
- Few satellites needed for globalcoverage
- Transmission delay (approximately 0.25 second)
- Most expensive to build and launch
- Longest orbital life (many years)
What are the characteristics of a MEO satellite?
Orbit: 10,350 km
USE: GPS
- Satellites move relative to point on Earth
- Moderate number needed for global coverage
- Requires medium-powered transmitters
- Negligible transmission delay
- Less expensive to build and launch
- Moderate orbital life (6-1.2 years)
What are the characteristics of a LEO satellite?
Orbit: 640-1,125 km
USE: Telephone
- 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)
Advantages and disadvantages for Microwave Transmission systems?
Advantages
- High bandwidth
- Relatively inexpensive
Disadvantages
- Must Have an unobstructed line of sight
- Susceptible to environmental interference
Advantages and disadvantages for Satellite Transmission systems?
Advantages
- High bandwidth
- Large coverage area
Disadvantages
- Must Have an unobstructed line of sight
- Expensive
- Signals experience propagation delay
- Must use encryption for security
Advantages and disadvantages for Radio Transmission systems?
Advantages
- High bandwidth
- Signal pass through walls
- Inexpensive and easy to install
Disadvantages
- Create electrical interference problems
- Susceptible of snooping unless encrypted
What’s a propagation delay?
Any delay in communications from signal transmission time through a physical medium.
What are the types of Wireless Network and the distance they cover?
- Short-range wireless networks (<30m)
- Medium-range wireless networks (<100m)
- Wide area wireless networks (<40Km)
What are the types of Short-range wireless networks?
- Bluetooth,
- Ultra-Wideband,
- Near-Field Communications (Like Apple Pay very short)
What are the types of Medium-range wireless networks?
- Wireless Fidelity (Wi-Fi),
- Wi-Fi Direct,
- MiFi,
- Li-Fi
What are the types of Wide area wireless networks?
A wireless wide area network (WWAN) is a specific type of network that sends wireless signals beyond a single building or property. By contrast, a local area network or LAN connects computers and other hardware pieces inside a residential or commercial property. Wireless wide area networks and wireless local area networks also differ in the types of signal processing technologies they use.
- Cellular radio,
- wireless broadband (WiMAX)
What’s Bluetooth?
It is an industry specification used to create small personal area networks - PAN.
- Bluetooth 5 transmit up to approximately 50 megabits per second (Mbps) up to 400 m
- Application: IoT, wireless handsets
What’s Ultra-Wideband (UWB)?
A high-bandwidth (Transmission capacity bits/s) wireless technology with transmission speeds in excess of 100 Mbps.
- Example: streaming multimedia from, say, a personal computer to a television.
- UWB tech enables firefighters to detect people behind walls, or in smoke-filled environments with zero visibility.
What’s Near-Field Communication?
a set of communication protocols that enable two electronic devices, one of which is usually a portable device such as a smartphone, to establish communication by bringing them within 4cm of each other. (Wikipedia)
- has the smallest range of any short-range wireless network.
- It is designed to be embedded in mobile devices such as cell phones and credit cards
What’s Wi-Fi?
It is a medium-range wireless local area network (WLAN)
- It is basically like a wired LAN (Ethernet networks), but without the cables.
- In a typical configuration, a transmitter with an antenna, called a wireless access point, connects to a wired LAN or to satellite dishes that provide an Internet connection.
What’s Wi-Fi Direct?
a new generation of Wi-Fi. => No hotspot, no wireless antenna
- enables peer-to-peer communications
- One device acts as an access point, and the other device connects to it using Wi-Fi Protected Setup (WPS) and Wi-Fi Protected Access (WPA/WPA2) security protocols
- challenge the dominance of Bluetooth in the area of device-to-device networking
- greater range
- much faster data transfer.
What’s MiFi?
a Small, portable, wireless device that provides users with a permanent Wi-Fi hotspot wherever they go.
- Users are always connected to the Internet.
- The range of the MiFi device is about 10 metres.
What’s Li-Fi?
- Light Fidelity – Light-based Wi-Fi Technology
- Similar to Wi-Fi
Differences with Wi-Fi
- Wi-Fi relies on electromagnetic waves at radio frequencies
- Li-Fi uses ultraviolet and infrared radiation
- Far greater bandwidth
- Very high peak data transmission rate (up to 10 Gbps)
- More effective in areas susceptible to electromagnetic interference (aircraft cabins and hospitals)
- Enhanced security due to reduced interception of signals
- Larger number of devices coverage
What’s Cellular radio?
- Cellphones
- 2-way radio communication
- We need a cell network
- We need radio antennas/towers so our cellphones communicate with them
- From my cellphone to antenna then move along the cells until it reaches the destination
- For a landline phone, then I need to get the message through PSTS
What are the generations of Cellular radio?
- 1st Generation of networks (voice only – using analog signals)
- 2nd Generation (digital signals – voice communications + data – text and smiles)
- 3G (digital + video, web, instant messaging, higher bandwidth) uses packet switching
- 4G is the 4th Generation of broadband cellular network technology: Secure mobile broadband, gaming services, high-definition mobile TV, video conferencing,… basically a hand-held computer
- 5G: 5th gen. tech standard for cellular networks deployed since 2019/2020
What comes with the 5G?
- 5G wireless devices in a cell are connected to the Internet & telephone network by radio waves through a local antenna in the cell.
- greater bandwidth, higher download speeds ( 10 Gbit/s) – download a HD DVD movie in seconds
- enables new applications in IoT and machine to machine areas.
- 5G enabled wireless devices must be purchased
- More antennas will be installed in cells specially in populous areas
4G vs. 5G
peak capacity
- peak capacity of 5G UWB sector is in gbps compared to 4G in mbps
latency
- latency, or the time that passes from the moment information is sent from a device until it is used by a receiver, will be greatly reduced on 5G networks, allowing for faster upload and download speeds.
bandwidth size
- 5G should be able to support many more devices of the future, in addition to the network demands of connected vehicles and other devices in the Internet of Things
What’s Wireless Boradband (WiMAX)?
- Worldwide Interoperability for Microwave Access, popularly known as WiMAX
- has a wireless access range of up to 50 kilometres, compared with 100 metres for Wi-Fi
- has a data-transfer rate of up to 75 Mbps
- a secure system, offers features such as voice and video
- antennas can transmit broadband Internet connections to antennas on homes and businesses several kilometres away
- provides long-distance broadband wireless access to rural areas and other locations that are not currently being served
What’s 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’s Radio-frequency identification (RFID) technology
What are the 4 Wireless security threats?
Wireless is a broadcast medium, and transmissions can be intercepted by anyone who is close enough and has access to the appropriate equipment
- Rogue access point
- Evil twin attack
- War driving
- Eavesdropping
What’s Rogue access point?
It is an unauthorized access point into a wireless network.
The rogue could be someone in your organization who sets up an access point meaning no harm but fails to inform the IT department. In more serious cases, the rogue is an “evil twin”—someone who wishes to access a wireless network for malicious purposes.
What’s an Evil twin attack?
It is an unauthorized access point into a wireless network. → On purpose with malicious intentions.
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 net- works 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, then 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 informa- tion such as usernames, passwords, and account numbers. In other cases, the attacker simply captures wireless transmissions. These attacks are more effective with public hotspots (e.g., McDonald’s and Starbucks) than with corporate networks.
What’s a War Driving act?
It is the act of locating WLANs while driving (or walking) around a city or elsewhere.
To war drive or walk, you simply need a Wi-Fi detector and a wirelessly enabled com- puter. 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.
What’s Eavesdropping?
refers to efforts by unauthorized users to access data that are travelling over wireless networks.
In radio frequency (RF) jamming, a person or a device intentionally or unintentionally interferes with your wireless network transmissions.
