Telecommunication Technologies:
Telecommunication today involves microprocessors, digitization of information (audio, video and text) and its transmission across communication networks. It also involves communications within a single office, between offices, branches, within or among single towns, regions, countries continents or even encompassing the entire globe. It involves linking the mainframe computers of all sizes and capacities via telephone cables, microwaves satellites to terminals anywhere in the world. Let us discuss as to how information is transmitted. The information may be in the form of sound (human voice) or it may be visual (printed page, microfilm, video picture) or it may be digital data. Whatever be the form, it must be converted into electrical signals (electromagnetic waves) before it can be transmitted over a given medium. The amount of information that can be sent over a given channel, in a given time, is dependent on the bandwidth of the channel. The bandwidth is dependent on the carrier frequency. Different channels possess different frequencies. Some of the channels are: twisted pair cables, coaxial cables, optical fibre cables and microwave and satellites channels. All these are also referred to as transmission media. The decision as to which medium to use is determined by such factors as distance involved, the areas to be covered and the type of information to be transmitted. The new technologies in telecommunications have led to new developments in equipment and facilities for creating, accessing, storing and receiving information as well as distributing it. Let us briefly discuss some of the information services which make use of recent developments in communications.