2. Transmitting & Receiving

3. Contents  Hardware for Transmitting & Receiving:By Ryan Caulfield  Software for Transmitting & Receiving: By Todd John  Non-Computer Tools for Transmitting & Receiving: By Ben Sargent  Social & ethical Issues: By Alex Kencevski  Hardware for Transmitting & Receiving:By Ryan Caulfield  Software for Transmitting & Receiving: By Todd John  Non-Computer Tools for Transmitting & Receiving: By Ben Sargent  Social & ethical Issues: By Alex Kencevski

4. Hardware Used For Transmitting and Receiving

5. Hardware for transmitting and receiving includes modems and networks as well as the internal components of the computer. These include: Ports Ports Modems Modems Networks Networks Local Area Networks Local Area Networks

6. A port is a socket used to connect peripheral devices. It is usually located at the rear of the system unit.  Parallel ports transmit eight bits (one byte) at a time along eight parallel lines. They are used to connect devices that send and receive large amounts of data such as printers and disk drives.  Serial ports transmit data one bit at a time using only one communication line. Serial ports are often called COM or communications ports and are assigned a number such as COM1 and COM2. Serial ports are used to connect almost any peripheral device, such as a mouse, keyboard, modem or plotter.  Parallel ports transmit eight bits (one byte) at a time along eight parallel lines. They are used to connect devices that send and receive large amounts of data such as printers and disk drives.  Serial ports transmit data one bit at a time using only one communication line. Serial ports are often called COM or communications ports and are assigned a number such as COM1 and COM2. Serial ports are used to connect almost any peripheral device, such as a mouse, keyboard, modem or plotter. Ports

7. A modem is a device that enables data to be transmitted from one computer to another. The word modem stands for modulator/demodulator. Modems may be internal or external.  Internal modems are a type of expansion card fitted into an expansion slot inside the system unit. Internal modems have become popular because they do not occupy desk space.  External modems are usually connected to a serial port (COM1 or COM2), require a power supply and take up some desk space. They have a set of status lights to indicate what the modem is doing, and are generally more expensive than internal modems. Modems may be internal or external.  Internal modems are a type of expansion card fitted into an expansion slot inside the system unit. Internal modems have become popular because they do not occupy desk space.  External modems are usually connected to a serial port (COM1 or COM2), require a power supply and take up some desk space. They have a set of status lights to indicate what the modem is doing, and are generally more expensive than internal modems. The speed of a modem is measured by the number of bits transmitted per second or the baud rate. A common transmission speed is 56000 bps, often abbreviated to 56K. Modems

8. When a number of computers (or terminals) and their peripheral devices are connected, it is called a network. The simplest form of a network is when one computer is connected directly to another computer using a cable. However, a network can also consist of hundreds of computers connected together. The devices used to send data to a computer system or receive data from a processor are called terminals. Terminals can be either dumb, smart or intelligent. Networks Dumb terminals do not contain a processor and usually consist of a keyboard and monitor. Smart terminals can do some low-level processing such as text editing. Intelligent terminals have both memory and processing capabilities. Most personal computers are classified as intelligent terminals and are called workstations on a network. Networks are classified according to the distances they cover and include local area networks and wide area networks.

9. Local area networks (LANs) connect computers (or terminals) within a building or group of buildings on one site. LANs operate in a small geographical area and the terminals are linked together by cables (coaxial or fibre optic). They are found in offices, hospitals, schools and tertiary institutions. LANs often contain a central computer called the network server. File servers are computers that perform a function for other computers on the network such as sharing hardware resources. There are three advantages in using a LAN: They allow limited hardware resources such as printers, hard disks and modems to be shared. They allow application software (word processing, databases, spreadsheets and graphics programs) to be shared. They improve communication among users on the network by allowing messages to be sent and received. Local area networks (LANs) connect computers (or terminals) within a building or group of buildings on one site. LANs operate in a small geographical area and the terminals are linked together by cables (coaxial or fibre optic). They are found in offices, hospitals, schools and tertiary institutions. LANs often contain a central computer called the network server. File servers are computers that perform a function for other computers on the network such as sharing hardware resources. There are three advantages in using a LAN: They allow limited hardware resources such as printers, hard disks and modems to be shared. They allow application software (word processing, databases, spreadsheets and graphics programs) to be shared. They improve communication among users on the network by allowing messages to be sent and received. Local Area Networks

10. Software For Transmitting & Receiving

11. Introduction  All software applications transmits and receives data within an individual computer.  Special communications software is used to send and receive data over networks and using modems.

12. Different software tools for Transmitting & receiving There are 4 different methods of transmitting & Receiving. They are:  Communications Software  Data Compression  Electronic mail (E-mail)  Data Encoding There are 4 different methods of transmitting & Receiving. They are: CCommunications Software DData Compression EElectronic mail (E-mail) DData Encoding

13. Communications Software Communications Software While hardware forms the physical interface between devices in the transmitting & receiving process, it is the software that controls the interface & how the process operates  Uses protocols to establish a connection.  A protocol is a set of rules that governs the transfer of data between computers. It defines how the information is transmitted and how errors are detected.

14. Communications Software  An IP (Internet Protocol) address is a unique set of numbers that identifies the individual computers on the Internet. IP addresses are also needed for dialup connections to the Internet.  Two computers must use the same protocols, otherwise the data transfer may be unsuccessful. There are a number of different protocols for networks, the most popular being Ethernet and Token Ring.

15. Communications Software

16. Data Compression  Data Compression reduces the number of bits required to represent data. It compacts the data so that it takes up less space on a disk and requires less time to download.  Compressed data must be decompressed in order to extract the original information. The amount a file is compressed is measured by the compression ratio.

17. Electronic Mail (E-mail)  E-mail technology has changed very little since it was invented.  When you send an e-mail message, the e- mail program running in your computer contacts the outgoing mail server computer at your ISP (Internet Service Provider)or LAN (Local Area Network)  E-mail technology has changed very little since it was invented.  When you send an e-mail message, the e- mail program running in your computer contacts the outgoing mail server computer at your ISP (Internet Service Provider)or LAN (Local Area Network)

18.  The mail server looks at the address on the message &, with the help of some address lists, sends the message to another mail server closer to its destination. There the process is repeated before it reaches the server at the destination address, where it is transferred to the incoming mail server.  The entire process can take less than a second. When the message recipient looks at their mailbox, their e-mail software contacts the incoming mail server at their ISP or LAN. Any messages waiting for them are sent to their computer & will appear in their ‘ inbox ’ window  The mail server looks at the address on the message &, with the help of some address lists, sends the message to another mail server closer to its destination. There the process is repeated before it reaches the server at the destination address, where it is transferred to the incoming mail server.  The entire process can take less than a second. When the message recipient looks at their mailbox, their e-mail software contacts the incoming mail server at their ISP or LAN. Any messages waiting for them are sent to their computer & will appear in their ‘ inbox ’ window

19. Data Encoding Encoding is the process of temporarily converting data into another form. Decoding reverses the process to restore the data to their original form. Encoding is the process of temporarily converting data into another form. Decoding reverses the process to restore the data to their original form.

20. Non-Computers Tool for Transmitting & Receiving

21. Social & Ethical Issues

22. Introduction  The widespread use of information technology has raised a number of ethical issues for people. The following are some of the issues that relate specifically to transmitting and receiving data:  The security of data transferred over the internet is a greater problem than data stored on a single computer.

23.  Privacy can be an issue when receiving information from the internet  Acknowledgment of sources is necessary when downloading data. Data obtained from the internet is protected by copyright  Privacy can be an issue when receiving information from the internet  Acknowledgment of sources is necessary when downloading data. Data obtained from the internet is protected by copyright More Facts  The internet is having an impact on traditional businesses.  Some businesses are being established that trade entirely online.  Many other businesses are establishing web sites

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