IGCSE ICT Marking Scheme Notes PDF

💻 IGCSE ICT Marking Scheme Notes , > ; are ms points Unit 1 1. Software: programs for controlling the operation of a computer or processing of electronic data. 2. System software: provides the services that the computer requ...

💻 IGCSE ICT Marking Scheme Notes , > ; are ms points Unit 1 1. Software: programs for controlling the operation of a computer or processing of electronic data. 2. System software: provides the services that the computer requires to operate. a. compilers, linkers, device drivers, operating systems, and utilities. 3. Applications software: Applications software provides the services that the user requires to solve a task a. word processing, spreadsheet, database management systems, control/measurement, audio editor, video editor, graphics editor, CAD, Apps/applets. IGCSE ICT Marking Scheme Notes 1  4. Hardware: consists of the physical components of a computer system. a. Internal components include Central Processing Unit (CPU)/processor, motherboard; i. CPU (Central processing unit): An item of hardware, It carries out the instructions of a computer program, It performs basic arithmetic calculations, It performs logical operations, It performs input/output operations of the computer, It contains the internal storage/control unit, Hardware components encompass graphics card, sound card, Network Interface Card (NIC), camera, and internal/external storage devices, as well as IGCSE ICT Marking Scheme Notes 2  input and output devices. b. Internal memory includes random access memory (RAM) and read-only memory (ROM); i. Similarities: Both are internal memory; Both are primary storage; The data on both can be read; Both are directly accessed by the CPU. ii. Differences: RAM is volatile, while ROM is non-volatile; RAM data can be read from and written to, whereas ROM is read-only; RAM is temporary memory, while ROM is permanent memory; ROM stores the start-up (BIOS) instructions, whereas RAM is used to store the current program/instruction. c. Input and output devices Input Output An output device is any hardware device hardware device that allows a user to that enter data manually or automatically into takes the output data from a computer and a computer puts it into a human-readable format Send data, cannot receive data (to Can receive data but not send another device) 5. Analogue data: values in a range, continuous data 6. Digital data: data that is discrete, binary. Only take 2 values 0 and 1. IGCSE ICT Marking Scheme Notes 3  7. The need to convert: Analogue to digital data so it can be processed by a computer. Digital data to analogue data so it can be used to control devices. 8. Operating System: Controls input, output and backing storage devices. Supervising the loading, running and storage of application programs. Error handling. Maintaining security. Allowing communication between user and the computer system. Maintains the computer log. Interfaces GUI (Graphical user interface) 1. Features: Window with example; Icon/buttons/tabs with example; Menu/drop- down menu with example; Pointer for menu items with example 2. 👍 Using a mouse/finger is simpler than typing in commands; quick, easy, no need to learn commands, Fewer errors are made than typing in commands; intuitive - allows the use of pinching, scrolling and expanding; exchange data between applications; more multi-tasking; touchscreen; icons speed up finding commands; 3. 👎 Takes up more RAM/hard disk space/memory / Can be slower for experienced programmers to use / Can be slower to run as graphics have to be loaded/larger program / Restrictive can only use pre-defined functions / Not in direct contact with OS/computer / more processing power CLI (Command-line interface) 1. Features: instructions memorised and typed; correctly 2. 👍 The user is not restricted to the pre-determined options//the GUI uses icons and set menus / The user has more control over the computer settings//in GUI computer settings are protected from the user / Uses less memory than GUI / IGCSE ICT Marking Scheme Notes 4  Requires less processing power for the interface / More processing power is made available for the task 3. 👎 The commands used have to be learnt / The commands used have to be remembered / The commands used have to be typed in/entered exactly / Have to remember the exact path/correct name of application / More prone to errors on data entry / Commands have to be typed in//in a GUI can use touchscreens/mice / Tends to be used by specialist people//GUI is more user-friendly and can be used by non-experts Dialogue-based interface 1. Software that interacts through speech recognition; uses the spoken word/voice to carry out actions/control devices. 2. 👍 Allows for hands-free control / Safer than using a standard interface / More useful for physically disabled users 3. 👎 Limited access due to the number of commands stored / More expensive to develop / May not operate reliably due to background noise/speech impediment/accents / Need to be ‘trained’ by the user / Can be distracting if the commands are not understood / Need to learn the commands Gesture-based interface 1. Where the human body interacts with the device; where a human gives a command without using a keyboard, mouse, or pointing device. 2. 👍 intuitive interaction, hands-free operation, natural user experience, and accessibility for users with mobility impairments. 3. 👎 Fatigue or "gorilla arm" can occur; users may unintentionally activate the device by moving their arms or fingers; it's not as accurate as other interfaces. Issues arise with stopping the gesture; if a user touches a button, the interface knows the command is completed. Users have to learn what the gestures do and remember them; this could cause damage if in a restricted space. There may be a limited number of gestures that can be used; users with physical disabilities may not be able to make the gestures accurately. Types of computers Desktops IGCSE ICT Marking Scheme Notes 5  1. A computer made up of separate units 2. Uses: Word processing, spreadsheets, finance software; interactive software for teaching or learning; games such as chess, crossword puzzles, and fantasy games; live or 'catch-up' streaming of television programs. 3. 👍 Separate elements offer more device choices and easy replacement; easier to upgrade; reduced screen glare; laptops may be more expensive for comparable performance/desktops are more powerful; lower risk of theft or loss; desktop can access more websites; Larger screen to read the typed data; Laptop uses a physical keyboard therefore easier to type; Larger keyboard to type in the data; Fewer data entry errors due to larger screen. 4. 👎 not portable, heavy, clutters desk space; larger footprint; need to buy storage media for transferring Laptop 1. 👍 Doesn't generate as much heat; Uses solid-state memory; Less susceptible to viruses; Battery life tends to last longer; Screens tend to be anti-glare; Larger screen and physical keyboard make typing easier and reduce data entry errors, more suited for entering mass amounts of data, laptop software typically has more features, more computer storage available, easier to connect additional devices for data storage. 2. 👎 No mouse, therefore pointing devices/touchscreen can be harder to use; Less portable and heavier than smartphones, smartphones are smaller and easier to carry, individuals are more likely to have a smartphone with them; more expensive than desktop; one single component, difficult to replace; can be stolen Smartphones 1. Characteristics: Uses Bluetooth/WiFi/3G/4G/5G; Lightweight; portable; front and back camera; built in battery; small footprint; on screen keyboard; antiglare; touch screens; use solid state memory; satnav; audio; texting 2. Uses: Text messaging; Sending and receiving emails; Make/receive phone calls; Order goods from the internet; Taking photos; Use it to surf/search the internet; Telephone/internet banking 3. Advantages: Smartphones are more portable and can be carried in a pocket / Students are more likely to have smartphones with them / If cameras are to be IGCSE ICT Marking Scheme Notes 6  used, then it is easier to use a camera with a smartphone / lightweight + smaller; Access the internet from more locations; easier to look things up on the go; screen and keyboard built into the device, making it easier to access websites; sat nav without maps; photos without camera; text message than telephone; 4. Disadvantages: smaller screen for viewing; onscreen keyboard - small; onscreen keyboard - difficult to type; less websites only accessible; easy to lose; need phone plan to make calls; battery needs recharging; distractions; Tablet 1. Advantages: Faster switch on as the operating system does not need to load; Easier to connect devices onto a tablet / Larger screen to see the findings / Larger on-screen keyboard to enter the data / Better software suited to the task. 2. Disadvantages: Smartphones are more portable and can be carried in a pocket / Students are more likely to have smartphones with them / If cameras are to be used, then it is easier to use a camera with a smartphone; expensive Phablet 1. Characteristics: hybrid of smartphone and tablet, has features of both, size between both, a tablet that functions as a smartphone 2. Advantages: Larger screen size makes it easier to read text/navigate/click on icons/type/edit text / Better control over screen layout/newsletter / More people can view simultaneously / Larger onscreen keyboard for easier data entry / Easier to connect devices 3. Disadvantages: Less portable than a smartphone / More difficult to record audio messages / Easier to use a smartphone for camera functions / Pupils more likely to have smartphones readily available. Emerging Technology IGCSE ICT Marking Scheme Notes 7  VR (Virtual reality) 1. devices: wand, treadmill, pressure mats, data gloves, headset, goggles, cameras, motion sensors, Head mounted device 2. uses: virtual museums, flight simulation, virtual tours, medical training 3. Three-dimensional; It can be explored and interacted with by a person; Replicates an environment; Computer-generated environment XR (Extended reality) 1. Mixture of Virtual Reality (VR) and Augmented Reality (AR): Combines real/physical world with digital world and interacts with each; Allows seamless interaction between the real and virtual worlds. 2. Used in: Rescue Training; Entertainment; Virtual shopping; Automotive Tours AI (Artificial Intelligence) 1. The use of a computer to perform tasks that mimic or duplicate the functions of the human brain AR (Augmented reality) 1. Gathering information, directional finder, visualizing real-life appearances; examples include gathering information about buildings, paintings, and products, IGCSE ICT Marking Scheme Notes 8  providing area information for navigation in airports, railway stations, and shopping malls, and aiding archaeologists, architects, and interior designers; additionally used for facial recognition by the police. Unit 2 💡 CRT monitors use more power than TFT monitors Device Characteristics/uses Advantages Disadvantages capture glare/shadow Capture images; Store more portable; faster off the image; digital camera digital data; Create data capture keystone effect; less digital images detailed does not capture Capture images; Store not portable; slower glare/shadow off the scanner digital data; Create data capture; large image; no keystone digital images footprint effect; more detailed Touchscreens are both an input and output device. They allow input Quick to select from the user through options; Small the use of a touch footprint; Improved touchscreen Used sensitive surface on the hand/eye Limited choices, in: Self-service screen. They also output coordination; Allows prone to dirt and kiosks, ATMs, data to the user, such as the user to use zoom scratches; germs mobile devices displaying the home and pinch making screen of a phone or item selection quick; displaying a number pad no training needed for the users to press the digits on. keyboard Entering data manually Easy method of slower than DDE; less into a computer; Typing entering data into a accurate than in commands to a computer; Easier to RFID/magnetic; RSI; computer carry out verification input errors; physical checks on data disabilities entered; large amount IGCSE ICT Marking Scheme Notes 9  Device Characteristics/uses Advantages Disadvantages of data can be entered At ATMs to key in PIN to Faster input method obtain money; At POS Keys can be small, than a standard terminals in case the making input difficult keyboard when barcode on an item fails for some people; numeric keypad entering numeric to scan properly; When Order of numbers on data; Easy-to-use using chip and PIN keypads is often not input device since it devices to make a card intuitive involves fewer keys payment Difficult to use by Faster method to people with certain Controls the position of choose on-screen disabilities; Can lead an on-screen pointer to options compared to to injuries such as mouse allow selections, a keyboard; Only RSI; Some surfaces open/close files and so requires a small don’t work well with on amount of desk mechanical mice space (mouse slips on the surface) Same advantages as not as easy as a Controls the position of a mouse; Since it is mouse; harder to drag an on-screen pointer to integrated into a and drop; RSI; people touchpad allow selections, laptop, there is no with limited wrist open/close files and so need to carry a movement find it on mouse around with difficult you Easy to lose, battery Distance operation, remote control TV, Blu-ray, hi-fi control replacement, line-of- easy interface sight required Control in limited Accurate, space- Costlier, unfamiliar to trackball spaces, luxury car saving, helpful for some users functions people with RSI too sensitive, lack of joystick/driving Gaming consoles, Realistic control, feedback; expensive; wheel simulators accuracy text entry cannot be done Speech/sound input, Fast input, voice Memory usage, microphone sensors activation verbal input accuracy IGCSE ICT Marking Scheme Notes 10  Sensors 1. Moisture/humidity sensor, Temperature sensor, Wind Speed sensor, Wind direction sensor, Light sensor, Pressure, Sound/acoustic, pH 2. Sensor monitoring process a. Data is read by the sensors > converted to digital data using the ADC > sent to the microprocessor/computer in the ground base unit either using a satellite link or radio waves > automatically produces graphs/results that are plotted against time > saves the data in the computer for later use. b. The computer receives the data from the sensor > Compares the data with pre-set values/stored data > Sends a signal to an alarm if data is outside limits > Takes no action if data is within limits > Stores the data for later analysis > Automatically sends the data to a monitoring system 3. Advantages of using sensors: Fewer errors, accurate, safer, 24*7/continuously as it will not forget to take readings; possible in hazardous or severe weather conditions; automatic and frequent data gathering sent to a computer, automatic reports are produced; multiple variables monitored at the same time; predictions can be made; wider view 4. Disadvantages: Faulty readings can lead to dangerous and spurious results; most sensors are analogue, requiring conversion to digital using an ADC, need training to use equipment, set up can be time- consuming and expensive; affected by weather 5. Devices that use sensors: Sat nav/GPS to help the driver travel between two points; Auto-parking systems; Automatic windscreen wipers that operate automatically; Cruise control; Lane drift systems; Automatic braking systems/ABS; Tyre deflation alert; Automatic lights/lights that shine round corners; Frost warning system; Fuel level indicator; Hand-brake alert; Airbag systems; Automatic maintenance alert; Expert diagnostic systems; Auto-gear change systems DDE 1. Both use direct data entry 2. Both are input devices 3. Both have improved security by using encryption 4. Both read/scan data using scanner/ optical/magnetic methods IGCSE ICT Marking Scheme Notes 11  5. Both are contactless Device Characteristics Uses Advantages Disadvantages Read at greater distance; no need for line of sight; easier readers are in updates; faster direct reading speed; contact/direct accurate; more data entry Race timing tracking; reusable/robust; devices; input event attendee larger storage cost; signal devices; tracking; livestock capacity; jamming; tag Readers scan tracking; library book RFID greater security; collision (data the product tracking; contactless no misreading if overlap); code; allow credit/debit card RFID grouped hacking; tracking of payment; together; can products; and passports/ID cards. read data even are contactless; with slightly uses radio damaged tags; waves read multiple tags simultaneously; contactless; Bar code readers are in Super markets; accurate; quick; Bar code readers direct libraries automatic stock readers only contact/direct control scan one bar data entry code at a time, devices; input require a direct devices; line-of-sight Readers scan with the code, the product need to be code; allow close to the bar tracking of code, and may products; and encounter read are contactless; errors with uses light damaged or scratched bar codes; may be switched; misread if grouped IGCSE ICT Marking Scheme Notes 12  Device Characteristics Uses Advantages Disadvantages together; less secure; wands to be bought More secure as Card may be encryption is read used to read the accidentally; card; Card Limited details can be withdrawal stored on a amounts; smartphone Increased fraud which might readers are in risk if have an extra direct lost/stolen; layer of Contactless contact/direct Some ATMs not Debit cards security; Stops card readers data entry contactless; shoulder devices; input Wireless card surfing; Only devices reading for allows a small unauthorized amount to be transactions; transacted; Security risk as quick and the card contactless, so contains no wear and personal tear; no need to information remember PIN; Magnetic stripe readers are in On credit/debit cards The transaction In the magnetic readers direct for use at ATMs or is faster using a stripe reader contact/direct POS terminals; magnetic stripe the card can be data entry Security cards to reader; Less used by anyone devices; input allow entry to a data entry as no PIN is devices building, hotel room, errors using a needed; (account and so on magnetic stripe readers can number, sort reader as no cause wear and code, expiry manual input; tear on the date and start more secure as cards; The user date) not human needs to have readable; data the card difficult to copy; present to use it; The card could be stolen and the signature IGCSE ICT Marking Scheme Notes 13  Device Characteristics Uses Advantages Disadvantages copied; magnetic stripe can be affected by magnetic fields; left in the lock; easy to clone; need to swipe The chip and the user needs Chip and PIN PIN reader is to know the readers the user susceptible to PIN; Chip and needs to know shoulder PIN reader the PIN; It is surfing; prompts the Payments in more secure as readers can Chip and Pin user to enter a restaurants etc. a PIN is needed; cause wear and Reader PIN; readers are Uses Wi-Fi for The chip cannot tear on the in direct contacting with bank be scanned cards; Security contact/direct remotely; limit risk as the chip data entry on spending is contains devices; input higher personal devices information OMR read data from Lottery tickets Faster (than OMR is unable printed Bar codes//QR codes OCR and data to recognize documents; entry) / machine or input large Multiple Choice Accurate / Less hand-printed amounts of forms//Questionaries errors than OCR characters data; and read / Cost effective (limited to data very Attendance registers for mass data choices) / For quickly. processing OMR to read, marks need to be within a specified area / The OMR marks have to be in the correct location / Need to design form / Expensive readers + designing form is complex / IGCSE ICT Marking Scheme Notes 14  Device Characteristics Uses Advantages Disadvantages Problems occur if the form is not filled in correctly OCR is more OCR requires read data from accurate at manual printed reading detailed intervention to documents; data / Data read change the Passports/ID Cards input large from an OCR scanned words OCR Scanning amounts of can be / not as ANPR data; and read manipulated by accurate as data very word OMR / can be quickly. processing more time software consuming More information than bar code; They can be read from many angles ; The Can be used to physical size of track stock ; the QR can be Can contain small therefore links to more takes up less information augmented reality; space on the QR about the attagging advertising; Wi-Fi box ; Can be products ; It read by any contains device with a information camera and about the suitable product; software; encryption is possible; robust than bar code; multimedia (links, email) 1. RFID Process: The chip is presented near a computer with a radio-frequency scanner > The scanning antenna puts out radio-frequency signals in a relatively short range > It provides a means of communicating with the transponder/the RFID IGCSE ICT Marking Scheme Notes 15  tag > The scanning device provides energy > so that the chips can broadcast the information in them > for the computer to read. Output devices Output device Uses of output device Advantages Disadvantages Heavy; runs hot; high Specialist areas like power consumption; Large viewing angle; Monitor: CRT CAD with light pen flickering screen may supports light pen use usage cause headaches and eye strain LCD: Very efficient, low LCD: Inconsistent color power consumption, and contrast from Main output device for lightweight and thin various viewing angles, computers, tablets, screens, no image motion blur and laptops, and burn-in or flickering, ghosting, weak pixels Monitor: LCD / smartphones; used in sharp image resolution, possible, requires LED touchscreen low electromagnetic backlighting; LED: technology; generally emissions; LED: No More expensive, prone used in large outdoor motion lag, low power to color shift and displays consumption, long inconsistent contrast lifespan, any size ratios screen Images can be fuzzy Enables many people with faded or incorrect to see a presentation, colors, expensive to Training presentations, Multimedia avoids the need for purchase and maintain, advertising, home projectors multiple networked difficult to set up, cinema systems computers, space- requires a darkened saving room, needs a separate audio system Expensive to run, Faster printing for large produce ozone gas and Where low noise is print runs, high-quality volatile toner particles, required, for fast, high- printing, long-lasting Laser printer cannot handle a variety quality, high-resolution toner cartridges, of printing materials, printing greater paper tray larger and heavier than capacity inkjet printers Inkjet printer Low-volume print runs, Low start-up costs, can Expensive ink, not high-quality colour handle many types of suited for long print IGCSE ICT Marking Scheme Notes 16  Output device Uses of output device Advantages Disadvantages printing, printing on paper and materials, runs, poor paper various materials refillable ink cartridges, fastness, requires compact and regular head cleaning, lightweight less durable than laser printers Very noisy, expensive Damp or dusty Cheap to run and to buy initially, slow environments, multi- maintain, suitable for Dot matrix printer printing speed, limited part or continuous long print runs, carbon colour options, poor stationery printing copies can be made print quality Architectural and High-quality drawings, Slow printing, engineering drawings, accuracy, can print on expensive initial Plotters animation characters, various materials, low investment, large large-scale drawings running costs physical footprint Prosthetic limbs, Rapid prototyping, Counterfeiting, illegal bespoke items, customization, medical activity, slow printing, 3D printer precision parts, fashion benefits, environmental expensive operation, and art, vintage car benefits potential job losses parts Multimedia presentations, Enhances Office environment Speakers or accessibility for presentations, aids disturbance, high cost loudspeakers disabilities, music accessibility, well- for quality sound playback, audible established technology warnings Control motors, pumps, Requires DAC Automates device switches, etc., enable interface, additional Actuators control, relatively computer control of potential point of inexpensive physical devices failure 3D Printers 1. 3D digital copy input; software slices into layers; printer creates layer by layer; layers bound together. 2. Create dental implants; Create anatomical models for surgery; Create skeletal models; Create blood vessels; Create customized tablets 3. Advantages: The manufacture of components is cheaper ; The whole process of setting up and printing the components can be quicker ; Quality is consistent ; IGCSE ICT Marking Scheme Notes 17  Minimizes waste ; Fewer sub-components making it stronger and safer ; 4. Disadvantages: The size of the component is limited to the size the 3D printer can produce ; If the initial design is incorrect it is harder to correct ; Initial cost of the printer could be more costly ; Requires skilled programmers/operators therefore the initial costs could be higher. Unit 3 STORAGE DEVICE: readers STORAGE MEDIUM: things that store data transfer rate / access rate / storage capacity / robustness / portability / reader/drive Internal storage examples: RAM and ROM / Internal storage is chip-based; Data cannot be erased/edited; fixed; can be read directly by CPU; fixed in the computer; data access time is faster; Backing storage can be solid state, optical, or magnetic / Backing storage is permanent storage / Non-volatile / Backing storage has slower access speeds / More storage in backing storage; does not take up internal storage; data can be read and written to*; Before data on a backing storage device can be read by the CPU, it must first be moved into RAM SSD read from and written to using semiconductor chips Media: memory sticks/pendrives/flash drives/USB sticks/flash memory card/SD card Advantages Disadvantages 1. SSD is lighter/smaller/thinner 1. expensive 2. making the laptop more portable; 2. small / easy to lose / stolen IGCSE ICT Marking Scheme Notes 18  3. quicker access and data transfer speed; 3. do not work on most systems so preferrable for storing OS and games (have port) 4. reduced risk of data corruption during 4. limited write cycles movement; 5. smaller size for a thinner laptop; 6. lower energy consumption; 7. decreased chance of impact damage. 8. solid state do not have to get up to speed before they work 9. There is less chance of the data becoming corrupted as it can save whilst the drive is being moved Pen drives Disadvantages Uses: Transporting files between computers and used as a security device to prevent 1. Easy to lose because it’s small software piracy. 2. Data might get corrupted if not ejected correctly Advantages 1. more robust as no moving parts 2. Can be more easily carried 3. Use less power 4. Have faster data access 5. Have faster data transfer times Memory cards IGCSE ICT Marking Scheme Notes 19  Magnetic Media: magnetic hard disks (fixed and portable), magnetic tape (serial access) Advantages Disadvantages 1. Less expensive per GB/gigabyte of 1. Data access time is slower / Data memory / Not as easily lost, as larger transfer rate is slower / Affected by in size / Large storage capacity magnetic fields / They have moving parts therefore less robust / Read and write is more noisy / Less compact than flash memory / Harder to transfer to other devices / Requires a special drive which is expensive Optical Media are read from and written to using a laser beam Media: CD, DVD, Blu-ray discs - direct access Advantages Disadvantages 1. More portable/less likely to 1. Limited capacity/slower access spike/cheaper to buy times/slower transfer rates/can be more easily/ lost/can be more easily 2. Faster access/transfer/robust than stolen/can be more easily scratched magnetic IGCSE ICT Marking Scheme Notes 20  Blu-ray Advantages Disadvantages 1. can store large amount of files with Blu-ray discs are more expensive large file size; preferrable for storing than other physical storage mediums images etc / portable like DVDs or CDs. Blu-ray players are required to read Blu-ray discs, which are typically more expensive than standard DVD players. They are susceptible to physical damage like scratches which can result in data loss. Blu-ray discs are not as widely adopted or as universally compatible as DVDs. As cloud storage and streaming services become more popular, the use of Blu-ray discs may decline, making it harder to find compatible devices and players. Unit 4 Types of network 1. LAN: Local Area Network / A network within a building/site/small geographical area / Network connected by hubs and switches. 2. WAN: Wide Area Network / Over a large geographical area / Tends to use satellite technology 3. WLAN: Wireless Local Area Network / Covers the hotel site / Uses wireless technology IGCSE ICT Marking Scheme Notes 21  a. The computer/device sends data to its wireless adapter > The data is converted into radio waves > The radio waves are transmitted > A wireless adapter receives the radio waves > Radio waves are converted into data > The computer initiates a handshake with the wireless router > The wireless router responds > Establishes a session/pairing > Wireless router checks the password/key is correct > Data is transmitted > User has to enter a password/passkey/automatic entry of key for known connections. Wi-Fi and Bluetooth 1. Similarities: Both WiFi and Bluetooth use wireless communications / Both WiFi and Bluetooth use radio frequencies for communication/radio waves / Both WiFi and Bluetooth allow several devices to be connected / Both use security when sending data. 2. Differences: WiFi has faster data transfer rate / WiFi has a greater range of transmission / WiFi uses key matching encryption / Bluetooth uses WEP and WPA security together / WiFi can be broadcast / Bluetooth has more channels / WiFi connects more devices. 3. Using Bluetooth to connect to a network: Bluetooth sends and receives radio waves > Enable Bluetooth > Bluetooth searches for the other devices > Pairs the two devices > Devices automatically detect and connect to each other > Used for short distances > Randomly picks channels to use one of 79 channels can be used > Uses spread spectrum frequency hopping > Constantly change the channels to stop interference with other communication systems > Used for low-bandwidth applications, e.g. streaming music > Used when the speed of transmission is not critical > Bluetooth can be used to create a secure Wireless Personal Area Network. 4. Using WiFi to connect to a network: Wi-Fi sends and receives radio waves in several different frequency bands > each band is also further split into channels > These channels allow multiple Wi-Fi networks to operate without interference > Channels have specific frequency ranges and bandwidths, optimizing device performance and minimizing interference > Wi-Fi routers and access points automate channel selection for optimal network performance. Network devices IGCSE ICT Marking Scheme Notes 22  1. Hub: Connects computers/devices so data can be broadcast to all devices / Expands a LAN 2. Network interface Card (NIC): Connect computers/devices to a network 3. Bridge: Connects two LANs of the same protocol together / A bridge creates a single LAN from separate parts 4. Switch: Connects computers together to form a LAN / Allows data to be sent to individual devices 5. Router: A router allows data packets to be sent to LAN/WAN; A router connects a LAN to a WAN; allows devices to connect to the internet Routers 1. Data is sent in data packets > Data is sent to the switch/hub and then passed to router > Each data packet contains an IP address of the next router > The router reads/checks/inspects the IP address > It checks the IP address against its routing table > Data packet is sent to the router with the IP address > The router uses the IP address to work out the best route/destination computer > The router stores the IP addresses > the router then passes it to the router of the other network that router passes it to the switch/hub > to the destination computer > It may use the MAC address of the switch to do that by converting the IP to a MAC using ARP 2. WiFi: Internet access from any room; no cables; multiple device usage. 3. Satellite: Broadband; good internet coverage; usable worldwide. 4. 3G/4G: Mobile device connectivity; wireless through 3G/4G network; access on the move; unaffected by rain or snow. 5. IP Address: Internet Protocol address; Unique identifier; IP addresses must be different for each device on a network; All devices connected to the internet use IP addresses; Determines the electronic location of the device 6. Routing table: IGCSE ICT Marking Scheme Notes 23  Used to determine where data packets will be directed; Stores route information; Stores IP addresses Cloud computing 1. online service/data storage; large groups of remote networked servers in many locations; allow centralised data storage; data redundancy; stored in more than one server 2. 👎 Loss of control of data; data controlled by storage provider; trust issues; security concerns; vulnerability to environmental factors; data remains on server, easier hacking; longer availability increases security risks; need for strong passwords/authentication; unencrypted data leads to security issues; loss of access in case of connection loss; potential issues with splitting data across servers; costlier than buying storage devices; difficulty in deleting all copies of a file; Can be issues if the internet drops during storing of data 3. 👍 greater storage capacity; Data accessible anywhere; facilitates data migration and synchronization and backup; no need to buy storage devices; useful for devices without built-in storage; ample storage space in the cloud; no need to manage storage; service provider handles security measures; allows multiple users to access data centrally; pay only for the storage used, avoiding wasted space on a hard disk; 4. Documentation is uploaded to the cloud > Access is given to members of the team > Members of the team log into the cloud > Members of the team open the documentation > Members of the team update the documentation > Documentation is synced > Can be tracked by the owner of the document > Several copies of the document are made. Intranet 1. Internal restricted access network; secure network; same protocols as the internet technology; private network; used within an organization (e.g., school); only limited and relevant resources; company has more control Internet 1. Public access; not policed; international network of networks; WAN/wide area network; worldwide/global/international; public information system; IGCSE ICT Marking Scheme Notes 24  web/email/gophers/social networking/video conferencing part of the internet. Extranet 1. An extranet is part of a company's intranet ; private network controlled by a company; The company gives permission for customers and suppliers to access it ; Enables businesses to exchange information over the internet in a secure way ; Requires credentials/username and password to access it. Internet Intranet Public network Private network/restricted access No rules Policed or managed Not moderated Moderated Less secure More secure Greater amount of information Moderated More chances of hacking on the Protected by passwords internet No owner Owned by organization Differences between intranet and extranet: 1. Similarities: Both have shared content ; Both use internet technologies / TCP-IP ; Both have restricted access ; Both sit behind a firewall. 2. Intranet shares data within an organization whereas Extranet shares content with customers/suppliers ; Intranet allows communication within the organization whereas Extranet allows communication with customers/suppliers ; Intranet is owned by a single organization whereas Extranet can be used by several organizations ; Extranet is part of a company’s intranet ; Extranet can lead to more security breaches. Audio conferencing 1. Characteristics: Audio-conferencing is where two or more people, in different locations, use technology to hold an audio call; all the participants dial into a central system that connects them, removing the need to directly call each other. 2. Setting up: Agree date and time of conference > Contact audio conferencing provider for organizer's PIN; for participant's PIN > Distribute PIN to participants > IGCSE ICT Marking Scheme Notes 25  Organize types in PIN at conference start > Participants dial number and enter PIN. a. Microphone; speaker; audio-conferencing software/app; internet/broadband connection. 3. 👍 Easier to set up; does not need specialist equipment, therefore saves money; no issue with lip syncing; less/no bandwidth is needed, therefore reduces hanging/freeze; more privacy as they do not use cameras; no time lag; in video conferencing, sound quality may be poor; Web conferencing 1. Characteristics: Real-time collaboration/communication; multiple users connected to the internet; see the same screen in their web browsers at all times; Communication using video cameras/microphones; A web-conference is conducted online/VOIP; web-conference uses IP technology/addresses; participants tend to be sat at computers and can view/hear other participants; web-conferences tend to be interactive; organiser allows participants to click a link to ask questions; participants are then queued; possible to draw or write on a ‘whiteboard’ using keyboard and mouse; possible to integrate chat, instant- messaging and communicate verbally; uses web browser 2. Uses: Slide presentations posted in advance, shared host's screen for live presentations/demos, delegate whiteboard interaction, webcam images/videos, pre-uploaded documents, verbal/instant messaging chat. 3. Webcams/cameras, large monitors/projector, microphones, speakers/headphones, NIC, route 4. 👍 The students save time as they do not need to travel to the school; The students save the cost of travelling to the school/going to stay in hotel; The school saves costs as it does not need to open in the holidays; Students and teachers can work from anywhere in the world; Can be recorded for students who miss the lesson; no need to transport equipment/documents; meetings at short notice; safer 5. 👎 Power cuts/load shedding may shut down parts of the video-conference; lip sync problems/time lag can cause discrepancies in audio-visual synchronization; consideration needed for time zone implications; initial high cost of hardware/software; requires reliable internet access to prevent interference; difficulty in managing simultaneous talkers; increased cost/time for staff training; additional cost/time for technician/support staff; limitations in document signing IGCSE ICT Marking Scheme Notes 26  and physical object examination during the conference; Disruptions due to hardware failures or loss of connection may hinder participation; Access limited to students with appropriate devices; More difficult to carry out projects as individuals are working on their own; difficult to form relationships with staff as individuals are working on their own; background noise/echo which could be distracting; users could be distracted and not pay attention to the meeting. Video Conferencing 1. Video-conferencing is the use of telecommunication technologies, utilizing an internet connection, to allow people in two or more locations to communicate, enabling long-distance communication through simultaneous two-way video and audio transmissions or streaming. Video Conferencing Web Conferencing Provides real-time two-way audio/video Can be either two-way or a webcast communication Tends to be via the internet Uses a phone or VOIP Requires specialised equipment on both ends Uses a computer Participants sit at their own Participants use a shared microphone and speakers computers Sound quality is poorer compared to web- conferencing Password protection Setting a strong password 1. 👍 Strong passwords essential; secure; avoid pet names; exclude personal info; birthdates off-limits; no reused passwords; company name not recommended; Difficult to guess; prevent shoulder surfing; resistant to cracking. 2. 👎 The passwords could become similar, weakening security; It may be more difficult to find a different password, weakening security; Users could easily forget the current password, leading to system lockout; It may be typed incorrectly as the password is like the previous one, leading to login errors; Users may have to write the passwords down so they are not forgotten, potentially exposing them to others; Letters and numbers could be confused, such as 1 and I, 2 and Z, 5 and S; the IGCSE ICT Marking Scheme Notes 27  complexity might lead to mis-typing; users may need to look at the keyboard while entering the password; and despite its strength, it could still be vulnerable to computer cracking. Evaluating a password 1. short ; Password is not strong ; It is easy to guess ; The letters and numbers are in sequence on the keyboard ; Easy to shoulder surf ; It should be changed regularly to secure his login ; contains personal information ; not containing mixture of upper case, lowercase, numbers or symbols 2. Why shouldn’t you use same password? If someone finds the password for one of the systems/accounts, other systems/accounts are compromised ; If someone finds the password for one of the systems/accounts, then he has gained the company password. 3. Password management: Change passwords regularly; Use a strong password; Do not write the password down; Do not tell anyone else the password; Must be easy for the user to remember; Use up-to-date anti-spyware. Authentication methods 1. Zero login a. Allows users to log in without passwords; Relies on smart technology and the ability to recognize a user with biometrics and behavioral patterns; The system builds up a complex user profile based on biometrics (e.g., fingerprints or face recognition) and unique behavior (e.g., where you normally use a device, how you swipe a screen, etc.) 2. Biometrics e.g. iris scan, face scan, retina scan. Something the user has. 3. Physical Tokens/TAN. Something the user knows. a. A physical token is a solid object commonly used by banks for remote account access. b. unique > inserted > read by computer > authorizes c. 👍 Ensures ensures that only the person access; Dongles are compact for convenience. d. 👎 Prone to loss or theft; Loss of dongle can lead to access issues; Security software malfunctions may block access. IGCSE ICT Marking Scheme Notes 28  4. Electronic token a. There are also software tokens, installed on a computer as an app. If a user wants to log on to a website using a tablet, for example, the user opens the app and an OTP is generated b. log in to software > generate OTP > enter code > authorized c. even if hacked, only for limited time; one time use 5. Two-factor/two-step/multi-factor authentication: To protect user’s data / credentials; To reduce the possibility of unauthorised access; Makes it more secure by adding an extra layer of security 6. Magnetic stripes. Something the user owns. a. use of hologram to prevent cloning b. 👍 easy, not expensive, deactivated if stolen c. 👎 easy to steal, many attempts, not as secure as biometrics, wear and tear 7. Smart cards. Something the user owns. a. contactless, RFID b. contains name, date of birth, security number, sex etc. 8. Memorable information // security question Unit 5 1. Measurement is the monitoring/recording of physical variables without the microprocessor taking action 2. Control is when the microprocessor takes action depending on sensor readings Microprocessing Computer checks the input from the user is authentic. > Computer is programmed with pre-set values. > Computer reads data from the sensors. > Compares with preset values > If the sensor is activated… > If analogue data greater than pre-set value… > Computer sends signal to output device. > Output device does action > Computer sends signal automatically to the police station/alarm company/security company. > IGCSE ICT Marking Scheme Notes 29  Computer sends signal the flashing lights/house lights. > Computer sends message/text/calls automatically to the owner > The process is continuous if not > no action/opposite action Advantages and disadvantages of microprocessors devices Advantages: Reduces the amount of time it takes to complete a task, therefore gives the user more leisure time/time to do other things. You can control the heating + other things from your smartphone so that you come home to a warm house / Control devices remotely Smart TVs allow programs to be recorded remotely TV on demand Money saving due to reduced utility bills as heating is only turned on when needed Smart fridges allow food to be automatically added to the food order The user does not need to be present when the device is working, therefore gives the user more/less exercise. Allows the user to use interactive games devices, therefore helps improves their fitness. Cameras can be viewed from the smartphone so intruders can be seen/reported Increased sense of security due to monitoring the CCTV remotely You receive immediate alerts if there is a security breach Disadvantages: When the device does all the work, it makes the user lazy. Users are not doing as much manual work, this can cause muscle atrophy. > lack of fitness and exercise Manual household skills are lost Can lead to unhealthy eating due to dependency on ready meals Using computers/gaming machines/devices for long periods, this can cause eyestrain. You may not be able to deal with the intruders if you are a long way away The wireless technology/data could be accessed by hackers > Security problem If access to the internet is lost then control of the system is lost Reliant on devices/power > Power failure Interference with walls Lack of privacy IGCSE ICT Marking Scheme Notes 30  Malware Expensive Autonomous devices 1. Advantages: The taxi can be controlled safely by the computer; Navigation systems find the quickest/safest route; Data is constantly being updated in the vehicle therefore reacts quicker to changes; Traffic efficiency improved; Fuel efficiency is improved as the vehicle finds the best way of getting from A to B; Roads will be safer as the vehicle can react faster to situations; Decreases the amount of accidents on the road 2. Disadvantages: Security problem of others gaining access to the vehicle and controlling its operation (e.g., slamming on the brakes); More expensive to set up wireless technology than manual systems; If the wireless technology malfunctions, the taxi will not be able to drive; The driver must remain alert in case of problems; Problem of disconnection stopping the vehicle (e.g., if the wireless signal stops, the vehicle will not operate); Requires a large number of new receiving stations, making it more expensive; Interference/weather can affect the signal and stop the vehicle; System failures can cause accidents; Higher cost of maintenance Health Problem Causes Solution eye strain Extended Take regular breaks/use no-flicker screens/LCD/TFT periods of screens/have eyes tested regularly/turn the brightness staring at a down/use blue screen/screen filters/blue glasses/I adjust computer the tilting screen correctly screen may lead to eye strain, exacerbated by glare or flicker, dirt on the screen, mismatched screen brightness with room lighting, sitting too close to the screen, IGCSE ICT Marking Scheme Notes 31  Problem Causes Solution or having the top of the monitor not aligned with the eyes. Sitting in front Use ergonomic chairs/use foot rests/regular breaks/sit with of a computer back pain good posture/height adjustable chairs/top of the screen is screen for long at eye level/exercises periods of time Potential risks associated with prolonged keyboard and mouse use include Ergonomic keyboards/regular breaks/less use of mouse/use RSI (fingers) musculoskeletal trackerballs/wrist rest/voice activated software strain, particularly when used with poor posture or in cramped workspaces. Potential risks associated with prolonged keyboard and mouse use include RSI (wrist) musculoskeletal Hands-free/less use of the mobile phone/wrist rest strain, particularly when used with poor posture or in cramped workspaces. headaches Incorrect Anti-glare screens/matt finish screens/regular breaks/ use lighting, screen no-flicker screens/LCD/TFT screens/have eyes tested reflections, regularly/turn the brightness down/use blue screen/screen flickering filters/blue glasses IGCSE ICT Marking Scheme Notes 32  Problem Causes Solution screens and so on Sitting in front of a computer neck pain Use foot rests/standing up screen for long periods of time deep vein Use foot rests/standing up thrombosis hearing loss Turn your headphone volume down Unit 6 Communication media Communication Characteristics Uses Advantages Disadvantages Media ePublications ePublications Audio ; Digital format allows Potential health allow Interactivity ; easy integration into issues multimedia Ability to other documents or associated with embedding in change to software, instant prolonged pages / auto different access across multiple computer use page changing languages ; devices, enhanced for reading, / and linkage of Ability to accessibility for the inability to sections change text disabled, and faster convert to internally or flow left-to- search capabilities. braille, potential externally / right and right- requirement for they are digital to-left ; Text to additional and can be speech ; software or used in other Accessibility ; readers, lack of documents / Video ; ownership as enabling reader Animation ; the book exists interaction and Turning pages only as data, simultaneous automatically. and the need to use by multiple purchase a users / device for additionally / reading along they remain with more up-to- dependence on IGCSE ICT Marking Scheme Notes 33  Communication Characteristics Uses Advantages Disadvantages Media date than internet access physical for magazines. downloading. Newsletters should be well- organized with easy-to-read layouts; consider using columns for extensive text and images, employing upper case and Newsletters bold fonts for emphasis, incorporating actual photos and clip art for visual appeal, but be mindful that they may still be discarded without being read. Posters Posters should include only pertinent details like event name, date, and contact information; they should feature vibrant, eye-catching designs, but bear in mind their transient IGCSE ICT Marking Scheme Notes 34  Communication Characteristics Uses Advantages Disadvantages Media nature, such as rental costs for billboard placement and susceptibility to weathering. susceptibility to hacking and viruses, potential pharming attacks, reliance on users having internet access and devices,