Telecommunications Engineering deals with the transmission of information across a channel such as a co-axial cable, optical fibre or free space. Telecommunication is the assisted transmission of signals over a distance for the purpose of communication. In earlier times, this may have involved the use of smoke signals, drums, semaphore, flags, or heliograph. In modern times, telecommunication typically involves the use of electronic transmitters such as the telephone, television, radio or computer. Early inventors in the field of telecommunication include Antonio Meucci, Alexander Graham Bell, Guglielmo Marconi and John Logie Baird. Telecommunication is an important part of the world economy and the telecommunication industry's revenue has been placed at just under 3 percent of the gross world product
Telecommunications engineering applies results from many other fields of science and technology. It utilizes mathematics, information theory, system theory, signal processing, electronics, information technology, and the essential results of the science of statistics. Telecommunications engineering covers the basic technology, systems, and software tools needed to build communication networks and network services.
A telecommunication system consists of three basic elements:
* a transmitter that takes information and converts it to a signal;
* a transmission medium that carries the signal; and,
* a receiver that receives the signal and converts it back into usable information.
For example, in a radio broadcast the broadcast tower is the transmitter, free space is the transmission medium and the radio is the receiver. Often telecommunication systems are two-way with a single device acting as both a transmitter and receiver or transceiver. For example, a mobile phone is a transceiver.
Telecommunication over a phone line is called point-to-point communication because it is between one transmitter and one receiver. Telecommunication through radio broadcasts is called broadcast communication because it is between one powerful transmitter and numerous receivers.
Analogue or Digital: Signals can be either analogue or digital. In an analogue signal, the signal is varied continuously with respect to the information. In a digital signal, the information is encoded as a set of discrete values (for example ones and zeros). During transmission the information contained in analogue signals will be degraded by noise. Conversely, unless the noise exceeds a certain threshold, the information contained in digital signals will remain intact. This noise resistance represents a key advantage of digital signals over analogue signals.
Networks: A collection of transmitters, receivers or transceivers that communicate with each other is known as a network. Digital networks may consist of one or more routers that route information to the correct user. An analogue network may consist of one or more switches that establish a connection between two or more users. For both types of network, repeaters may be necessary to amplify or recreate the signal when it is being transmitted over long distances. This is to combat attenuation that can render the signal indistinguishable from noise.
Channels: A channel is a division in a transmission medium so that it can be used to send multiple streams of information. For example, a radio station may broadcast at 96.1 MHz while another radio station may broadcast at 94.5 MHz. In this case, the medium has been divided by frequency and each channel has received a separate frequency to broadcast on. Alternatively, one could allocate each channel a recurring segment of time over which to broadcast this is known as time-division multiplexing and is sometimes used in digital communication.
Modulation: The shaping of a signal to convey information is known as modulation. Modulation can be used to represent a digital message as an analogue waveform. This is known as keying and several keying techniques exist (these include phase-shift keying, frequency-shift keying and amplitude-shift keying). Bluetooth, for example, uses phase-shift keying to exchange information between devices.
Modulation can also be used to transmit the information of analogue signals at higher frequencies. This is helpful because low-frequency analogue signals cannot be effectively transmitted over free space. Hence the information from a low-frequency analogue signal must be superimposed on a higher-frequency signal (known as a carrier wave) before transmission. There are several different modulation schemes available to achieve this (two of the most basic being amplitude modulation and frequency modulation). An example of this process is a DJ's voice being superimposed on a 96 MHz carrier wave using frequency modulation (the voice would then be received on a radio as the channel
Telecommunications Engineers or Telecom Engineers come in a variety of different types from basic circuit designers to strategic mass developments. A Telecom Engineer is responsible for designing and overseeing the installation of telecommunications equipment and facilities, such as complex Electronic Switching Systems to copper telephone facilities and fiber optics.
Telecommunications is a diverse field of engineering including electronics, civil, structural, and electrical engineering as well as being a political and social ambassador, a little bit of accounting and a lot of project management. Ultimately, Telecom Engineers are responsible for providing the method that customers can get telephone and high speed data services.
Telecom Engineers use a variety of different equipment and transport mediums available from a multitude of manufacturers to design the telecom network infrastructure. The most common mediums, often referred to as plant in the telecom industry, used by telecommunications companies today are copper, coaxial cable, fiber, and radio.
Telecom Engineers are often expected, as most engineers are, to provide the best solution possible for the lowest cost to the company. This often leads to creative solutions to problems that often would have been designed differently without the budget constraints dictated by modern society. In the earlier days of the telecom industry massive amounts of cable were placed that were never used or have been replaced by modern technology such as fiber optic cable and digital multiplexing techniques.
Telecom Engineers are also responsible for keeping the records of the companies equipment and facilities and assigning appropriate accounting codes for purposes of taxes and maintenance. As telecom engineers responsible for budgeting and overseeing projects and keeping records of equipment, facilities and plant the telecom engineer is not only an engineer but an accounting assistant or bookkeeper (if not an accountant) and a project manager as well.