Communication Technologies Made Simple

Chapter 1. Concepts of Information Communication and Technology

IT (Information Technology)

It encompasses all of the technology that we use to collect, process, protect and store information. It refers to hardware, software (computer programs), and computer networks.

ICT (Information and Communication Technology)

This concept involves the transfer and use of all kinds of information. ICT is the foundation of the economy and a driving force of social changes in the 21st century. Distance is no longer an issue when accessing information; for example, working-from-home, distance learning, e-banking, and e-government are now possible from any place with an Internet connection and a computing device.

1.1 Hardware

1.1.1 Hardware Basics

The concept of hardware includes computer components, the physical and tangible parts of the computer, i.e., electrical, electronic, and mechanical parts which comprise a computer.

Computer working principle:

Fig. 1.1 Computer working principle

Computer working principle: data is entered into a computer via input devices, processed and stored in a system unit, and finally displayed by the output device.

Personal Computer

A personal computer (PC), as the name suggests, is intended for personal use, as opposed to the server, which is used by a larger number of people simultaneously, from different locations, often via terminals. If you do not intend to move your computer frequently from one place to another, and at the same time you want a maximal price/performance ratio, then you should use a desktop computer. Compared to laptops or tablet computers, it is much larger, inconvenient to carry/move, consumes more electricity but has a much better price/performance ratio. Also, they are much easier to upgrade.

Laptop Or Tablet Pc

A laptop or tablet PC is used by individuals who need to travel with a computer or simply use them for aesthetic reasons when computing power is not an issue. As opposed to tablet PCs, laptop computers more closely resemble a personal computer when it comes to data input. Data entry is done via keyboard and mouse, while the tablet PC data entry is done via touch screen. Unlike desktop computers, notebooks and tablet PCs are optimized for portability, low power requirements at the expense of performance and can be used (for a limited period of time-i.e. until the batteries are depleted) without connection to the power grid. To prepare a laptop or a tablet computer for use without a power connection, it is necessary to recharge the batteries.

Portable Digital Devices - PDA

Personal Digital Assistant (PALM) is a convenient small-sized computer. It easily connects to mobile phones and can prove a good solution for less demanding users. As the name suggests, it is a device that fits in the user’s palm. Its name directly tells us that this computer is more of an assistant and not a workstation-whose name suggests the superiority in capabilities and computing power, especially in comparison with PDA.

A mobile phone is a portable electronic device used for distant communication. In recent years, the mobile phone has evolved from a simple communication device into a multi-functional device. Additional functions, such as short text messaging (SMS), electronic mail, Internet access, contact registration, calculator, clock, alarm, recording and photograph displaying, recording and playback of video clips, sending/ receiving multimedia messages (MMS), audio recording and playback, etc. have turned the mobile phone into an extremely useful device, whose absence would make active involvement and participation in modern society not possible.

A smartphone is a device that merges the functionality of phones, PDAs, cameras, camcorders, and computers. To function properly, Smartphones use operating systems, which are the basis for application development. Some smartphones can be connected to an external screen and keypad, which creates a working environment similar to that of a laptop or a desktop computer. Some operating systems for Smartphone are: GoogleAndroid, Symbian, Blackberry, PalmPilot, and WindowsPhone

Main Computer Parts

• System Unit

The system unit (case) contains a computer’s vital parts. There are two basic types of cases: Desktop casing is placed on a desk in a horizontal orientation.

Towers come in 3 sizes (mini-tower, mid-tower, and full-tower), and it is vertically orientated.

Motherboard, MBO is the computer’s basic circuit, to which all computer components are connected, directly or indirectly. Devices are connected to the motherboard through a system bus. The system bus connects all devices, ensures data flow and communication between different devices using predefined protocols. A protocol describes the manner in which communication between devices is defined. It enables them to address each other and defines how they should look for each other on either system bus or network. Buses can, according to the purpose, be divided into:

•Serial-USB, Firewire, etc.

•Parallel-AGP, PCI, etc.

•Mixed-Hyper Transport, InfiniBand, PCI, etc.

The Central Processing Unit (CPU or processor) is a central part of a computer (and can be referred to as the computer’s brain). It manages all other computer parts, monitors their mutual communication, and performs logical arithmetic operations. Processor speed is measured in hertz (or megahertz or gigahertz). The most famous manufacturers for personal computer processors are Intel and AMD

A cache is a small capacity memory that allows quick access to data. By storing data from working memory in the cache, the speed of communication between processor and RAM is increased. Microprocessors use three levels of fast cache, L1, L2, and L3, used to store often-used data.

ROM (Read Only Memory) is a type of permanent, internal memory used solely for reading. BIOS (Basic Input/Output System), a program that is located in a separate ROM on the motherboard and defines, as the name suggests, a basic input/output system, is a good example. Please note that not all BIOS programs are stored in ROM.

RAM (Random Access Memory) is a working memory in which analyzed data and programs are stored while the computer runs. It allows reading and writing data and is deleted/cleared when the computer shuts down.

Hard Disk Drive (HDD) is a place for permanent data storage (it does not delete/clear when the computer shuts down). Its features are: large capacity, faster performance compared to optical devices but slower compared to RAM and are used for permanent data storage. We can distinguish between internal and external hard drives.

Floppy Disk Drive is used for storing and reading data stored on a floppy disk. The disk capacity is 1.44MB. Before memory sticks and wider usage of CD recorders, it was used as a data carrier. ‘Modern memory sticks have a memory capacity measured in GB while floppy disks only have a memory capacity of 1.44MB, indicating that floppy disks are becoming obsolete.

CD-ROM drive is used for reading CD media

DVD drive is used for reading DVD discs. DVD capacity ranges from 4.7 to 18GB.

Soundcard is a device used for sound creation and production using computer speakers.

Graphics card is responsible for image processing and displaying it on a monitor. It has its own graphics processor and memory. The image quality depends on the strength of these components.

Modem enables computers to communicate via telephone lines. They connect computers to the Internet.

Connectors or ports are slots visible in the back and the front side of a computer.

• Common Input /Output Ports

Universal Serial Bus (USB) connects various devices (mouse, keyboard, USB memory).

Serial port is used, for example, in connecting a mouse (labeled COM1 or COM2).

Parallel port is used for connecting a local printer (LPT1 or LPT2).

Network port is used for connecting computers to a network.

Firewire - used for connecting computers and audio-video devices (digital cameras, etc.)

1.2 Computer Performance

Factors affecting computer performance:

•processor clock speed,

•amount of cache and number of kernels

•the amount of installed RAM

•graphics card- its memory and processor

•clock bus

•number of running applications

Applications use computing resources. The processor runs applications and performs code that defines applications; therefore, processors get the most workload when running the application. For processors to execute the application, the application code must be loaded into the system memory. As a result, running applications take up a certain amount of working memory. The more applications are running, the greater the load on the processor and RAM. That is why the computer’s performance depends on both the processor (clock speed, number of cores, cache memory) and the amount of working memory and the number of applications running.

Processor speed is measured in hertz (Hz), and due to the large working clock speed of today’s processors, it is expressed in megahertz (MHz) or gigahertz (GHz). Besides the frequency, the processor performance depends on the number of operations that the arithmetic-logic unit (ALU) performs in one clock cycle.

1.3 Memory And Storage Devices

OM (Read Only Memory) is a type of permanent, internal memory used solely for reading. BIOS (Basic Input/Output System), a program located in a separate ROM on the motherboard and defines, as the name suggests, a basic input/output system, is a good example.

RAM (Random Access Memory) is a working memory in which analyzed data and programs are stored while the computer runs. It allows reading and writing data and is deleted/cleared when the computer shuts down.

Measurement units

Bit (binary digit) is the basic unit used to measure the amount of information. A byte or octet contains eight bits.

1 KB (kilobyte) - 1024 B (approx. 1000 B)

1 MB (megabyte) - 1024 KB (approx. 1000 KB)

1 GB (gigabyte) - 1024 MB (approx. 1000 MB)

1 TB (terabyte) – 1024 GB (approx. 1000 GB)

Basic Types Of Storage Devices

CD (Compact Disc) is an optical disc used for data storage. The standard capacity of a CD is 700MB. CD-R is used to read and write data once only, while CD-RW for reading and writing data multiple times.

DVD (Digital Versatile Disc) is an optical disc that is mostly used for video storage due to its larger capacity (about 4.7 GB).

Bluray disc (BD)- the successor to DVD, is optical disk storage; it comes in different capacities, depending on how many layers it has and the capacity of each layer. Currently, the capacity of one layer is between 27 GB and 33 GB, while the overall capacity is the product of the number of layers and capacity of each layer.

Memory card is a type of flash memory used to store data in digital cameras, cell phones, MP3 players, etc.

USB Stick is a data storage device. It features small dimensions, relatively high capacity, reliability, and speed. It belongs to the type of flash memory that remembers data, even when not under-voltage, i.e., they do not need electric power to maintain data integrity.

There is a difference between an internal hard disk drive, which is embedded in the computer case, and an external hard disk drive, which is connected to a computer by using an appropriate cable or USB port and is usually used to transfer data from one computer to another or for backup.

1.4 Input And Output Devices

Input devices:

A mouse is an input device that facilitates work with the graphical user interface (GUI). The mouse transmits hand movements, and the screen displays the cursor (mouse pointer) movements. They are divided into mechanical and optical (with respect to a transfer movement) and wired and wireless (with respect to connection).

Trackball, unlike a mouse, is not movable. Hand movements are transmitted to the screen by rolling the ball located on the upper side of the device.

The keyboard is used for data entry and issuing commands. They can also be wired or wireless.

A scanner is used to load data (image, text, etc.) from the printed material into a computer. The result of scanning is an image, but with special programs, if we scan the text, we can get a text as a result. Software used to recognize text from an image is called a text recognition tool.

The touchpad is used for transmission of hand movement, but unlike working with a mouse, the user is the one who determines the position of the cursor by touching the touchpad.

Lightpen enables handwriting on-screen and can be used as a mouse. It requires an appropriate monitor type.

A joystick is mainly used in computer games. Unlike a mouse, it has many buttons which allow control over game objects.

A microphone is a device that converts sound into an electrical signal stored on a computer. It is mainly used for recording sound, communication between players in online games, in combination with a web camera in video conferencing, for converting voice into text on a computer (speech-to-text processing (e.g., textual files or emails), etc.

A webcam is a camera that stores video signals in a format appropriate for video transfer over the Internet in real-time.

Digital cameras, unlike analog, store photographs in digital format. It can be directly connected to a computer, and photographs can be downloaded. Photograph quality is expressed in megapixels. More megapixels mean better quality of the photograph; however, more memory is occupied. Digital cameras, unlike analog, store photographs in digital format. It can be directly connected to a computer, and photographs can be downloaded. Photograph quality is expressed in megapixels. More megapixels mean better quality of a photograph; however, more memory is occupied.

Output devices

Monitor displays images from the computer; it enables us to see, work and control computers. In other words, working on a computer without a monitor would be inconceivable. Common types of monitors, with regard to manufacturing technology, are the CRT and LCD.

CRT monitors have been present on the market for a long time, and other technologies are pushing them out. They are based on cathode tube technology.

LCD monitors use liquid crystal technology. Compared with CRT monitors, LCD monitors use less electrical energy, do not emit radiation, and their price is higher; however, they are pushing CRT monitors out of smaller dimensions, more attractive design, and good picture quality the market. Monitor size is expressed by the size of the screen diagonal and measured in inches (‘’). Picture quality is expressed with the notion of the resolution, which is a number of horizontal and vertical dots (pixels) (e.g., 1920x1080).

A projector is a device used to project a computer image or other images from independent devices, such as DVD players, Blu-ray players, etc., onto canvas or a wall.

A printer is a device used for printing data from a computer onto paper. We distinguish between a local printer (connected directly to the computer) and a network printer (connected directly to the network using a network card). Also, printers differ according to print technology: dot matrix, laser, inkjet, thermal printer, and plotter.

Dot-matrix printers are the oldest, with the lowest print price per paper; they are slow, make a lot of noise while printing, and are most appropriate for printing text.

Laser printers are similar to photocopy devices when it comes to technology. They have exceptional print quality, speed and are quiet. The downsides of laser printers are their high price and the high price of toners.

Inkjet printers have a high print quality (somewhat lower in comparison with a laser printer), they are quiet while printing, and they have a low initial investment. Ink price, especially color ink, can cost as much as the printer itself. Printing technology is based on ink dispersion from a container onto paper.

A plotter is used for printing large drawings (up to A0). They are extremely expensive and used only for professional purposes, such as designing firms for printing technical drawings (blueprints).

Thermal printer, as its name states, leaves a print on the paper by utilizing heat. They use paper sensitive to heat, feature small dimensions; they are quiet while printing, and relatively cheap. They are usually used for printing receipts, and owing to that, they are called POS printers (printer of sale). Also, they are used as calculator printers and, due to their small dimensions, as portable printers.

Input and output devices

Storage devices, due to the necessity for writing and reading data, are classified as input/output devices.

Touch screen (i.e., monitor sensitive to touch) is out device while displaying computer image, and at the same time input device while receiving manual orders.

1.5 Software

Software is, unlike hardware, an intangible part of the computer. It consists of a sequence of commands, written according to strict rules. Programs are written by programmers in various programming languages.

Software types:

An operating system is a program that manages computer hardware. First, computers did not have operating systems; they had directly loaded programs into the computer (e.g., punchcards). Today, computers have an operating system that loads into the computer’s memory during its startup. Computer functions are based on its operating system. Within the operating system, drivers (responsible for the functioning of a computer) and various utility programs (responsible for a computer’s functionality) are installed. The most famous operating systems are:

1. Linux (Debian, Ubuntu, Fedora, Knoppix,...) - open-source software

2. Microsoft Windows (XP, Vista, 7,...) - proprietary software

3. Mac OS X (Cheetah, Panther, Snow Leopard,...) - proprietary software

Application Software (Utility programs) are all programs that users use to perform different tasks or for problem-solving. Users, according to his/her needs, install the appropriate utility software. Computer functions and tasks that computers can perform are defined by the installed utility software. Utility software can often cost more than computer hardware unless the software is open source.

Common Utility Softwares

Text processing software is used for creating and forming text documents, and nowadays, they can contain images, charts, and tables. Examples of such programs are OpenOffice.org Writer (open source software) and Microsoft word (proprietary software).

Spreadsheet calculations software is used for performing various calculations and presentation of results in charts. Examples of such programs are OpenOffice.org Calc Writer (open source software) and MicrosoftExcel (proprietary software).

Software for presentations is used to create professional presentations that consist of slides with graphical and textual elements. Such a presentation can afterward be displayed as a slide show by using a projector. Examples of such programs are OpenOffice.org Impress (open source software) and MicrosoftPowerPoint (proprietary software).

Software for creating and managing a database helps to manage a collection of structured data. Examples of such programs are OpenOffice.org Base (open source software) and MicrosoftAccess (proprietary software).

Common utility software installed on a computer:

•Office programs - OpenOffice.org, Microsoft Office

•Antivirus programs - Avira, Sophos, Kaspersky, Antivir, etc.

•Internet browser - Mozilla Firefox, Microsoft Internet Explorer, Opera, Safari, etc.

•Programs for image editing - Adobe Photoshop, Canvas, CorelDraw, Draw, etc.

1.5.1 Programs To Facilitate Easier Computer Accessibility

We can access accessibility options: Start menu → All Programs → Accessories → Ease of access

Magnifier is used to enhance a part of the screen.

On-Screen Keyboard – text is entered using a mouse to click on the on-screen keyboard.

The narrator is commonly used by users with visual impairment - it can read text displayed on a monitor, tells current