Introduction to Communications Technologies
Communication technologies have been around for centuries in some form or other. Throughout history man has used all manner of methods to send messages over long distances, including drums, signal beacons, reflected sunlight, and birds and animals that have served as couriers. In the last two centuries, the discovery of the electromagnetic spectrum and the practical application of electricity and have made far more advanced forms of communication possible. The second half of the nineteenth century saw the invention of both the telegraph and the telephone, while the first half of the twentieth century witnessed the evolution of those technologies, together with the arrival of wireless communication, radio and television broadcasting, and radar. The last sixty years have seen astounding advances in communications technology that have made it possible for most if not all of the world?s population to access vast amounts of information and entertainment media at the touch of a button, communicate with friends or family on the other side of the world in real time, and transact business through the exchange of electronic messages.
Businesses today rely on the ability of computers to communicate with one another over high speed data communication networks, and most of us now make use of the Internet and mobile communications networks for purposes ranging from voice or text communication and social interaction to shopping for groceries or checking our bank balance. The availability of cheap, versatile mobile communications devices and the growing range of additional services available to mobile users has made the ownership of a mobile phone or personal date assistant almost as commonplace as owning a television. Even in the developing world, communication technologies have transformed people's lives beyond recognition. Indeed, the very different priorities faced by countries in the developing world have triggered the development of new and innovative solutions to meet specific needs.
Communication technologies are all around us – in our homes, in business, and in government. They support education, health and emergency services, and law enforcement agencies. They control the distribution of utilities such as water, gas and electricity. They regulate and monitor the transport infrastructure. They allow funds to be transferred electronically and provide vital data channels to support financial services. The list is almost endless, but effectively, the entire social, economic, and political fabric of modern society is underpinned by electronic communication systems. An understanding of the technology that makes these sophisticated communication services both available and affordable is therefore vital. The breakdown of our global telecommunications infrastructure would be catastrophic. Even the failure of a few key communication satellites could have serious short term consequences. It is therefore essential that we have people who can design, build, and above all maintain this vital technology.