1. Describe the difference between an analog signal and a digital signal.
An analogue signal is a continuous wave where any value is possible within the maximum and minimum values of the wave. A digital signal consists of electric pulses where there are only two possible values, zero and a specified value (we usually consider a digital signal to be made up of 0 and 1).
2. What is the function of a modem?
A modem is used at the transmitting end to convert the digital signal of a computer into the analogue wave needed for transmission. At the receiving end the opposite occurs. The analogue wave is converted into a digital signal.
3. A mobile telephone is an example of a wireless device that can be web-enabled. What does the term ‘web-enabled’ mean?
A web-enabled device is one that provides access to the Internet and email from any location. It can be held in one hand.
4. Describe the five main advantages of using a network over stand-alone computers.
The advantages of a network over stand-alone computers are:
Communicating – Email, chatting, videoconferencing are all efficient ways of communicating over a network.
Sharing resources – Resources such as printers and file servers can be shared between multiple users.
Sharing data and information – All authorised users on a network can access data and information stored on the network
Sharing software – User of a network can share software, usually through the use of site licences.
Transferring funds – Users connected to a network can use electronic funds transfer to move money securely via transmission media.
5. What is a network? How is a local area network (LAN) different from a wide area network (WAN)?
A network is a collection of computers and devices connected by communications channels (cabling, wireless, infra-red, satellite). A local area network is confined to a limited geographic area such as a school or small business. A wide area network covers a large geographic area.
6. Describe four important tasks of a network operating system.
A network operating system is required to:
Administer the network by adding and deleting users and maintenance tasks such as backing up the system.
Manage files by keeping track of locations and transferring them when required.
Manage printing by prioritising jobs and sending documents to the appropriate printer.
Keep the network secure by controlling the access of users.
7. How does a peer-to-peer network differ from a client/server network?
A computer on a peer-to-peer network stores files on its own storage device and can share printers, data or information located on any other computer on the network. A client/server network uses one computer (or more) to act as a server and other computers on the network can request services from that server.
8. Briefly describe three common network topologies
A bus network consists of a single central cable, to which all of the other computers and devices connect.
A ring network uses a cable that forms a ring. All computers and devices on the network connect to the ring.
In a star network, all of the devices connect to a central computer in a star arrangement.
9. Which of the network topologies is most suited to environments where devices may need to be added or removed on a regular basis? Why?
A star network is most suited to an environment where computers or devices may be regularly added or removed from the network since there is no central cable and therefore no disconnection across the whole network if one channel is temporarily unavailable.
10. What is an intranet? What benefits to organisations are there is setting up an intranet?
An intranet is an internal network in an organisation that uses Internet and Web protocols to securely share information and policies with employees. Intranets restrict access to company information and facilities to employees.