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Communication is a mode used for transmitting data from one place to another. Earlier, communication used to take place using courier, a chain of semaphore and then gradually, copper wire were introduced in various devices for transmission of data.
History
Historically, people found telegraph as the most reliable mode of communication. But, successively, with the advent of radio, television technology followed by telex, the best mode of communication kept changing. Over the last 10 years, these new technologies that have joined the horse race are Fax, Paging, High Speed Analog Modems, Analog Cellular, ISDN, Central Optical Fiber. In addition to them, new technologies that have begun to emerge as an essential part of communication include Digital Cellular, Digital Radio, Low Cost One Way Satellite, and Cable Modems. Now on the near horizon new technologies such as Low Cost Two Way Satellite, Optical Fiber to Curb are being considered. The general trend of these technologies is two fold, a move from analog based technologies to digital technologies and an increase in the speed and bandwidth of data transmission.
Analog and Digital devices
There are two ways of carrying out electronic Communication i.e., by Analog devices and digital devices.
Analog devices: In analog devices, a signal (or wave) is recorded and used in its original form. Thus,
An analog circuit that operates with currents and voltages vary continuously with time and has no abrupt transitions between levels. Hence, for measuring physical quantities, like velocity and temperature, which vary continuously (as does audio), an analog circuit provides the best means of representing them
Digital devices
: In digital devices, currents or voltages exist only at one of a set of discrete levels, and all transitions between levels are ignored. The main advantage of digital device is that they produce digital signals that are more robust and less subject to transmission errors.
Advantages of Digital devices over analog devices -
1. Less expensive compared to Analog devices
2. More reliable
3. Easy to make changes
4. Flexible
5. Compatibility with other digital systems
6. Only digitized information can be transported through a noisy channel without degradation
7. Integrated networks
Summary
Due to research, the development in the field of communication has been progressing at a furious pace. But they are not radical changes in the basic forms of communication. They are simply enhancements to already-existing communication techniques. To be precise, the various enhancements taken place in the communication field are as follows. Firstly, the advancement in technology has greatly expanded the number of places in which we can communicate and the distances over which we can. Secondly, they have enhanced the time frame in which we communicate. Lastly, they have increased the quality and richness of the information that can be conveyed when we communicate. Information can be sent quickly in a time frame convenient to the information provider, and it can be retrieved quickly in a time frame convenient to the end consumer. Thus, Rapid distribution of printed, sound, graphic, and video information is now common place.
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