LO1

Cards (97)

  • What are the disadvantages of copper cables
    poorly insulated (susceptible to electromagnetic interference), more likely to suffer from attenuation, lower bandwidth
  • Describe the internet connection: copper cables.
    the most common method - as copper cables are used in the old telephone lines, uses analogue technology
  • What are the advantages of copper cables?
    cheaper, malleable, less likely to break, already integrated in the network/existing infrastructure so no need to replace any cables
  • Describe the internet connection: fibre optic cables
    signals are transmitted as waves of light through a glass tube
  • What are the advantages of fibre optic cables?
    high bandwidth, can transfer data at speed of light, not affected by electromagnetic interference, suffer less from attenuation
  • What are the disadvantages of fibre optic cables?
    expensive, fragile, cost effective - as they'd have to dig up the whole network to switch cables
  • What are the disadvantages of using bluetooth?
    requires close proximity (within 10m), only temporary communication,
  • What are the advantages of using bluetooth?
    no other hardware is required, does not require line of sight, reliable, used for wireless peripherals
  • What are the disadvantages of microwave communication?
    antennas must be in line of sight with no obstructions, can be affected by bad weather, high chances of attenuation (network distortions)
  • What are the advantages of microwave communication?
    can send signals over a large area, can transmit large amounts of data
  • What are the advantages of satellite communication?
    suited for remote areas that are far from cellular towers or wired network infrastructures i.e. natural disaster zones
  • What are the disadvantages of satellite communication?
    satellites are far so there is a high chance of losing data, coverage depends on positioning of satellites, delay between data transmission and receiving it due to distance
  • Describe the internet connection: satellite.
    use point-to-multipoint communication, satellite is called geostationary, distance of satellite from earth is roughly 45000 miles
  • Describe the internet connection: GSM
    Global system of mobile communication, uses cellular towers to transmit signals to allow devices to communicate with each other
  • who are the holders of information
    • business
    • government
    • individuals
    • educational organisation
    • healthcare
    • charities
    • community organisations
  • business
    they hold information(date of birth, address, etc) on all their employees as well as commercial information(profits/losses, product descriptions, etc) about themselves - they may hold information about their competitors too
  • government
    hold information about the citizens of the country(tax paid, births/deaths, etc) - also stores information about other countries
  • individual
    they will hold information about themselves or others such as their friends and family(address, phone number, date of birth, etc)
  • educational organisations
    holds information about current and past students as well as their staff (addresses, attendance records, examination history, etc)
  • healthcare
    hold entire medical histories for each civilian in the country (basic personal information, blood type, allergies, etc) - stores information that is usually confidential and should not be shared with anyone other than the citizen in question
  • charities
    hold information about donors(financially) and their projects(that their charity is funding) as well as their shops too
  • community organisations
    hold information on members, matches, meetings or events (sports centres or religious institutions)
  • the location of systems and data affects access speed and network quality
    the digital divide is the gap between people who do and do not have easy access to computers and networks
  • developed countries (western europe, north america, east asia) 

    they have a more developed technology and industry base with more funding available for information infrastructures such as cabling and high speed access
  • developing countries (africa, central asia)
    they usually have unstable governments and slower access(if any) to the internet - less money is spent on technology and expensive equipment like computers cannot be purchased at low wages
  • urban(towns and cities)
    they have a high population density so IT companies would spend a lot of money on internet infrastructure such as cabling and installing high speed lines
  • rural (countryside)
    population is sparse and settlements may be far apart so the internet access is poorer and speeds are slower - accessing information on the internet is more difficult
  • remote locations (mountains or deserts)
    limited internet access, expensive to install fast fixed broadband - many ISP wont invest in rural areas as it is not economically viable
    slower or interrupted download speeds - intermittent connection - take a long time to access webpages/documents
    some may have no fixed internet access - difficult to work/communicate online
  • alternatives to fixed broadband in remote locations
    • mobile broadband - generally not designed for home use (very expensive for everyday use) - mobile coverage could be weak
    • satellite broadband - requires dish with unrestricted view of the sky - relatively high internet speed but expensive to install and has high latency (more chance of experiencing lag)
  • identify types of storage medias
    • magnetic storage
    • optical storage
    • solid state storage
    • paper based storage
  • magnetic storage - hard disk drive/ floppy disk(obsolete)/ magnetic tape(serial access only)
    large capacity
    cheaper per GB than solid state
    not durable or portable when powered on because moving it can damage the device
    relatively quick access speed but slower than solid state
  • optical storage - CD/DVD/Blu-Ray
    low capacity - 700MB/4.7GB/25GB
    not durable - discs are very fragile can break/scratch easily
    very portable - they are very thin
    slowest access speed
  • solid state storage - solid state drives/USB/memory cards - has no moving parts
    replacing HDDs in modern computers and consoles because they are quieter, faster and use less power
    high capacity but more expensive per GB than magnetic
    durable but cheap USB sticks can snap or break
    small size (USB/memory cards) - very portable
    fastest access speed because it has no moving parts
  • paper storage - printed or hand written documents

    relatively inexpensive, can take up a lot of physical space, environmentally damaging (requires physical security methods to keep safe)
    low capacity - a page can only hold a certain amount of information
    poor durability - can easily tear and become damaged in rain
    portable - a single sheet of paper can be folded and placed in pocket but large stacks are difficult and expensive to transport
    paper's access speed depends on how organised it is and how easy it is to find
  • identify types of handheld devices
    • smartphone
    • e-reader
    • smartwatch
    • small tablet
  • identify portable devices
    • laptops
    • larger tablets
  • identify fixed devices
    • desktop computers
    • smart tvs
    • games consoles
  • identify shared devices
    • database server
    • cloud storage devices
    • data centres
  • handheld devices are smaller and lighter than portable devices and can possibly be worn on the human body - they are becoming more powerful over time with extra features, storage options and network connectivity
  • fixed devices are not meant to be moved once installed - they are usually connected to other devices via cables and wired networks and they are bulky and require a constant power connection