1212 Flashcards
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Distinguish between 2.4GHz and 5GHz Wifi. When might you choose to use each?
2.4GHz Wifi: This frequency band offers a longer range and better ability to penetrate walls and other obstacles, making it suitable for larger homes or buildings where coverage is essential. However, it’s also more susceptible to interference from other devices like microwave ovens, cordless phones, and Bluetooth devices. It’s a good choice for general internet browsing, email, and other basic tasks.
5GHz Wifi: While the 5GHz frequency band provides faster speeds and less congestion, it has a shorter range and struggles more with obstacles. Therefore, it’s better suited for environments with fewer obstructions and where high bandwidth is necessary, such as streaming high-definition videos, online gaming, and transferring large files.
Explain what is meant by the term 5G. Is there currently any issues with 5G, which might be hampering its deployment across numerous countries?
5G: 5G refers to the fifth generation of mobile network technology, succeeding 4G LTE. It promises significantly faster data speeds, lower latency, and higher capacity, enabling a wide range of new applications and services, including autonomous vehicles, virtual reality, and the Internet of Things (IoT).
Issues: Despite its potential benefits, 5G deployment faces several challenges. Some concerns include health risks associated with radiofrequency radiation, potential interference with aviation and weather radar systems, and geopolitical tensions affecting the supply chain and standards development. Additionally, there are debates over spectrum allocation and infrastructure investment, which vary from country to country and can impact the pace of deployment.
What is the purpose of a router? When might a mobile device connect to one?
Purpose of a Router: A router serves as a central hub for routing data packets between different networks, such as between a local area network (LAN) and the internet. It manages network traffic, assigns IP addresses, and provides security features like firewalls and virtual private network (VPN) support.
Mobile Device Connection: Mobile devices often connect to routers for internet access. This connection may occur at home, where the router provides Wi-Fi connectivity, or in public places like cafes or airports, where Wi-Fi access points are available. Routers allow mobile devices to access shared resources, such as printers or network-attached storage (NAS), and provide a gateway to the internet.
Explain the difference between Intranet and Internet
Intranet: An intranet is a private network that operates within an organization, typically using internet protocols and technologies. It is accessible only to authorized users and provides a secure platform for sharing information, collaborating on projects, and accessing internal resources such as databases, documents, and applications.
Internet: The internet is a global network of interconnected networks that spans the globe, allowing communication and information exchange between users worldwide. It provides access to a vast array of resources, services, and information, including websites, email, social media, online shopping, and more.
Briefly describe two of the sensors which might appear in a modern Mobile Computing device and what their purpose is
Accelerometer: An accelerometer is a sensor that measures acceleration forces, including the force of gravity. In mobile computing devices, accelerometers are commonly used to detect changes in orientation and movement. They enable features like automatic screen rotation (portrait to landscape mode) and motion-based interactions in games and apps.
GPS (Global Positioning System): GPS is a satellite-based navigation system that provides location and time information anywhere on Earth. In mobile computing devices, GPS sensors receive signals from satellites to determine the device’s precise geographic coordinates. This enables location-based services such as mapping, navigation, location tracking, and geotagging of photos and social media posts.
Distinguish between Wireless Access Point and Ad-Hoc Wireless Networking approaches. Where might you use each? Give an example of each in your answer
Wireless Access Point (WAP): A WAP is a central networking device that allows wireless devices to connect to a wired network. It serves as a bridge between wireless clients and the wired network infrastructure. WAPs are commonly used in homes, offices, and public spaces to provide Wi-Fi connectivity. Example: Wi-Fi router in a home network.
Ad-Hoc Wireless Networking: Ad-hoc networking allows wireless devices to connect directly to each other without the need for a central access point. This type of networking is useful in scenarios where temporary or spontaneous connections are needed, such as file sharing between laptops or smartphones in a meeting or conference without access to a Wi-Fi network.
Explain what is meant by the term ‘Near Field Communication”. Give examples of devices and services which might use this.
Near Field Communication (NFC): NFC is a short-range wireless communication technology that enables two devices to establish communication by bringing them close together, typically within a few centimeters. Examples of devices and services that use NFC include contactless payment systems (e.g., Apple Pay, Google Pay), transit cards (e.g., London Oyster card), electronic door locks, and Bluetooth pairing between smartphones and other devices.
Explain the purpose of a “Hub”. Distinguish between the three types.
Purpose of a Hub: A hub is a basic networking device that connects multiple devices in a network, allowing them to communicate with each other. It operates at the physical layer of the OSI model and simply relays data to all connected devices.
Types of Hubs:
Passive Hub: Passively relays signals to connected devices without amplifying or regenerating them.
Active Hub: Actively regenerates signals before transmitting them to connected devices, helping to overcome signal degradation over longer distances.
Intelligent Hub: Provides additional features such as monitoring, management, and diagnostics capabilities, allowing for more efficient network administration.
Distinguish between a LAN and a WAN, in the context of networking and network devices
LAN (Local Area Network): A LAN covers a limited geographic area, such as a home, office, or building, and connects devices within close proximity. It typically uses Ethernet or Wi-Fi technologies for communication and offers high-speed connectivity with low latency and high security.
WAN (Wide Area Network): A WAN spans larger geographic areas, such as cities, countries, or even continents, and connects multiple LANs or other networks together. It often relies on public infrastructure like the internet and employs technologies like leased lines, MPLS, or VPNs for connectivity. WANs offer lower-speed connections with higher latency compared to LANs.
Explain which of the following network addresses could exist on a network where the router has the address 192.168.7.254 and a subnet mask of 255.255.255.0
Answer: Option b: 192.168.7.63. This falls within the same subnet as the router (192.168.7.0/24), where the range of valid IP addresses is from 192.168.7.1 to 192.168.7.254. Therefore, 192.168.7.63 is a valid address within this range. A could not be as, although the first three parts of the address are the same (required for Class C addresses), the last part is too high a number (must be in the range 0-254)
C also could not be on the same network. This is due to the first three parts not being the same as the other address (192.168.4.x vs. 192.168.7.x)
Briefly describe 2 advantages and 2 disadvantages of using Wireless networking
Advantages:
Mobility: Wireless networking allows users to connect to the internet or other devices without being tethered to a specific location, providing flexibility and convenience.
Ease of Installation: Wireless networks are relatively easy to set up compared to wired networks, as they eliminate the need for running cables and drilling holes, making them ideal for temporary or dynamic environments.
Disadvantages:
Interference and Signal Degradation: Wireless signals can be affected by interference from other electronic devices, physical obstacles, and environmental factors, leading to signal degradation and reduced performance.
Security Concerns: Wireless networks are more vulnerable to unauthorized access and security breaches compared to wired networks. Encryption and security protocols are essential but may add complexity to network management.
Explain what is meant by the term ‘Near Field Communication”. Give examples of devices and services which might use this.
Near Field Communication (NFC): NFC is a short-range wireless communication technology that enables two devices to establish communication by bringing them close together, typically within a few centimeters. Examples include contactless payment systems (e.g., Apple Pay, Google Pay), transit cards (e.g., London Oyster card), electronic door locks, and Bluetooth pairing between smartphones and other devices.
Explain the purpose of a “Wireless Access Point”. Explain why these might be of benefit to mobile devices.
Purpose of a Wireless Access Point (WAP): A WAP serves as a central networking device that allows wireless devices to connect to a wired network. It provides Wi-Fi connectivity by transmitting and receiving wireless signals, allowing mobile devices like smartphones, tablets, and laptops to access the network and the internet.
Benefits to Mobile Devices: WAPs enable mobile devices to connect to networks in various locations, such as homes, offices, airports, and cafes, without the need for physical cable connections. This flexibility and mobility allow mobile users to access resources, share data, and communicate seamlessly while on the go.
Distinguish between a LAN and a WAN, in the context of networking and network devices
LAN (Local Area Network): A LAN covers a limited geographic area, such as a home, office, or building, and connects devices within close proximity. It typically uses Ethernet or Wi-Fi technologies for communication and offers high-speed connectivity with low latency and high security.
WAN (Wide Area Network): A WAN spans larger geographic areas, such as cities, countries, or even continents, and connects multiple LANs or other networks together. It often relies on public infrastructure like the internet and employs technologies like leased lines, MPLS, or VPNs for connectivity. WANs offer lower-speed connections with higher latency compared to LANs.
Explain what is meant by the term ‘Touchscreen’ and give a basic explanation of how one might work (how it functions, not how it is used)
Touchscreen: A touchscreen is a display screen that responds to touch, allowing users to interact with it directly using their fingers or a stylus. It works by detecting the electrical charge from the user’s touch, which triggers a response on the screen, such as tapping or swiping. Touchscreens may use different technologies, including resistive, capacitive, or infrared, to detect touch input and convert it into digital signals that the device can interpret and respond to accordingly.
