Consider all the different communications that take place in an organization. Some communications are face to face, but others use some type of technology. Think of email, phone calls, text messaging, viewing pages on the Internet, downloading files. All of these communications make use of a telecommunications system. A telecommunications system is a collection of nodes and links to enable telecommunication. Telecommunication is communication at a distance using electrical signals or electromagnetic waves.
Examples of telecommunications systems are the telephone network, the radio broadcasting system, computer networks and the Internet. The nodes in the system are the devices we use to communicate with, such as a telephone or a computer.
Components of a Telecommunication System
In its most fundamental form, a telecommunication system includes a transmitter to take information and convert it to a signal, a transmission medium to carry the signal and a receiver to take the signal and convert it back into usable information. This applies to any communication system, whether it uses computers or not.
Most modern day telecommunications systems are best described in terms of a network. This includes the basic elements listed above but also the infrastructure and controls needed to support the system. There are six basic components to a telecommunications network.
1. Input and output devices, also referred to as ‘terminals’
These provide the starting and stopping points of all communication. A telephone is an example of a terminal. In computer networks, these devices are commonly referred to as ‘nodes’ and consist of computer and peripheral devices.
2. Telecommunication channels, which transmit and receive data
This includes various types of cables and wireless radio frequencies.
3. Telecommunication processors, which provide a number of control and support functions
For example, in many systems, data needs to be converted from analog to digital and back.
4. Control software, which is responsible for controlling the functionality and activities of the network
5. Messages represent the actual data that is being transmitted
In the case of a telephone network, the messages would consist of audio as well as data.
6. Protocols specify how each type of telecommunication systems handle the messages
For example, GSM and 3G are protocols for mobile phone communications, and TCP/IP is a protocol for communications over the Internet.
While early telecommunication systems were built without computers, almost all systems we use today are computerized in some way.
A computer network is a system of computers and peripheral devices that are connected electronically. These connected computers can communicate with each other, which means that they can share information. Each computer has its own network address, so it can be uniquely identified among all the computers in a network. Computer networks are able to carry different types of data and support different applications.
Computers are connected using a number of different types of communication channels. These include both wired and wireless connections. Wired connections consist of an actual physical cable, such as copper wire or fiber optics. Wireless connections do not use a physical cable but transfer data using waves at a particular part of the electromagnetic spectrum.
Why do we need a computer network? Transferring files between individual computers can be accomplished using physical media, such as DVDs or external hard drives, but a computer network makes it possible to transfer data between computers without having to use physical media.
Some of the advantages of computer networks are:
- File sharing
- Internet connection sharing
- Sharing of peripheral devices
- Improved cost efficiency
- Increased storage capacity
The network itself can also carry out tasks that are difficult for any single computer to do. These network services have become increasingly important as many different types of devices are connected to each other.