After reading this article you will learn about the use of statistics for the improvement in the methods of communication. Statistics: Inventors are usually practical people, their forte being their capability to convert theoretical concepts into practical forms. Faraday, although a self-taught man from a humble background, became a famous inventor, but it was left to James Clarke Maxwell to [...]
After reading this article you will learn about: 1. Rules of Data Transmission 2. Analog and Digital Data Transmission 3. Transmission Impairments 4. Modulation 5. Modems 6. Error Detection 7. Error Correction. Rules of Data Transmission: The design decisions that concern the rules for data transfer require that one specifies whether data will travel in only one direction or both [...]
At the present time, there are three methods of connectivity available in India. These are: a. Connectivity through wireless transmission: b. Connectivity through telephone landlines: Connectivity through telephones includes three recommended methods. These are: Connectivity through dial-up lines; connectivity through leased lines and connectivity using ISDN (Integrated Services Digital Network). c. Connectivity through VSAT: Connectivity' through VSAT has two recommended [...]
The following example is adapted from an example given by Hughes Escort. This example may help to explain TDM/TDMA (Time Division Multiplexing/Time Division Multiple Access )technology in a very simple way. It seems many of us are working backwards in this age of technology. It is amusing, but true to a large extent. Instead of explaining the new technologies in [...]
Wireless communications may require the use of different facilities at different times. These are: Radio transmission and Microwave transmission. We shall look at each of them separately. 1. Radio Transmission: Radio transmission is one of the ways that wireless transmission can take place; the other widely used method of wireless transmission usually is microwave transmission. All these methods of transmission [...]
This article throws light upon the following two standards that are mainly used in telephone systems. The standards are: 1. Narrowband ISDN 2. Broadband ISDN. 1. Narrowband ISDN: The present public circuit switched telephone system meant chiefly to cater to voice transmission, is largely analogue. However, in spite of these advantages the telephone systems throughout the world continue to be [...]
This article throws light upon the top five modes of communication available in India. The modes are: 1. Wireless Communications 2. Telephone Communications 3. Satellite Communications 4. Satellite Networks 5. Selecting a Means of Communication. Mode # 1. Wireless Communications: Cables, however, may not necessarily be the answer in all the cases of data communications. Other methods of data communications [...]
After reading this article you will learn about the role of multiplexing in telephone communication. Other issues that may be important in telephone communications are related to multiplexing. Since it costs the same amount to lay cables (whether copper or Fibre Optic) for narrowband transmission as it does for broadband transmission, it is natural that the telephone authorities try to [...]
A summary of all the facilities provided by the telephone system is given below: 1. Dial-up telephone lines using the standard switching circuits. Over long distances the connections may use copper wires, Optical Fibre or microwave. Generally, the circuits are analogue although they are gradually being converted to digital circuits. In India, normally in dial-up lines the bandwidth available is [...]
Two different methods are used for switching in telephone systems. These are Circuit Switching and Packet Switching. Of these, circuit switching is older and currently in use with most of the telephone systems throughout the world. Packet switching is relatively new and recent advances in telephone systems have permitted many telephone systems to utilise packet switching. While it is possible—indeed [...]