Technology Guide 4: Basics of Telecommunications and Networks

Question One: Describe the basic telecommunications system?

Telecommunications systems consists of hardware and software that transmit information form one location to another. These systems can transmit texts, data, graphics, voice, documents, or full-motion video information with two basic types of signals, analog and digital

Question Two: Compare and contrast the main wired communications channels? (Ethernet & Fibre Optic)

There are three main wired communication channels, they are:

• Twisted-pair Wire (also known as Ethernet): this is the most prevalent form of communication made up of strands of copper wire twisted in pairs. It is relatively inexpensive, widely available and easy to work with. However, there are significant disadvantages, it is relatively slow for transmitting data, it is subject to interference from other electrical sources and can be easily tapped by unintended receivers for gaining unauthorized access to data.

• Coaxial Cable: is made up of insulated copper wire. It is much less susceptible to electrical interference and can carry much more data than the twisted- pair wire. It is commonly used to carry high speed data traffic, however, it is more expensive, inflexible and more difficult to work with than the twisted-pair wire.

• Fiber Optics: consists of thousands of very thin filaments of glass fibers that transmits information via light pulses generated by lasers. The fiber optic is surrounded by cladding, a coating that prevents the light from leaking out of the fiber. These cables are significantly smaller and lighter, can transmit more data and provide more security from interference and tapping than traditional cable media. IT is typically used as the backbone for a network. One problem associated with fiber optics is attenuation which is the reduction in the strength of a signal.

Below is an image of a Fibre Optic Cable:

Question Three: What are the main business reasons for using networks?

Computer networks are essential to modern organisations for many reasons:

1. Networked computer systems enable organisations to be more flexible so that they can adapt to rapidly changing business conditions.
2. Networks enable companies to share hardware, computer applications and data across the organisation and among organisations
3. Networks make it possible for geographically dispersed employees and workgroups to share documents, ideas and creative insights. This encourages teamwork, innovation and more efficient and effective interactions
4. Networks are a crucial link between businesses and their customers

Question Four: What is the difference between LANs and WANs?

A local area networks (LANs) connects two or more devices in a limited geographical region, usually within the same building, so that every device on the network can communicate with every other device. Every device in a LAN has a network interface card that allows the device to physically connect to the LAN's communications medium. This medium is usually an unshielded twisted-pair wire.

Wide area networks (WANs) are networks that cover large geographic areas and typically connect multiple LANs. WANs generally are provided by common carriers such as telephone companies and the international networks of global communications services providers.

Question Five: What is a network protocol?

Computing devices that are connected to the network access and share the network to transit and receive data. These components are often referred to as ‘nodes’ of the network. They work together by adhering to a common set of rules that enable them to communicate with one another. This set of rules and procedures that govern transmission across a network is a protocol.

Question Six: Describe TCP/IP protocol.

Transmission Control Protocol/Internet Protocol (TCP/IP) is the protocol of the Internet. TCP/ IP uses a suite of protocols, the main ones being the Transmission Control Protocol and the Internet Protocol. The TCP performs three basic functions;

1. It manages the movement of packets between computers by establishing a connection between the computers
2. It sequences the transfer of packets
3. It acknowledges the packets that have been transmitted.

The IP is responsible for disassembling, delivering and resembling the data during transmission.