communication in physics related to analog and digital

. Let us now focus our attention on modems that provide communication between a user and an Internet Service Provider (ISP) over the PSTN. Traditionally, the PSTN has been viewed as an analog network. However, in reality, the PSTN has become an almost entirely digital ..

Analog and Digital Communication - The concept of information is central to communication. There is no precise definition of the word "information". So, instead of information, we deal with "message". Message is defined as the physical manifestation..

The concept of information is central to communication. There is no precise definition of the word "information". So, instead of information, we deal with "message". Message is defined as the physical manifestation of information as produced by the source There are two distinct ..

A common format for encoding different kinds of message signals (e.g., speech signal, video signal, computer data, etc.) for the purpose of transmissio..

The development of telephone, telegraph and telex enables us to transmit messages instantly. The development of radio and television satellites has revolutionised the means of communication. Advances in electronics (computers, calculators and lasers) have greatly enriched the soci..

The disadvantages associate with digital communication systems include (i) Increased transmission (ii) Increased system complexity Although digital communication is becoming increasingly attractive for practical use, it is a fact that analog c..

Symmetric Modem Configuration - The simplest approach to the design of modems is to treat the entire PSTN as a linear analog network. [Note that PSTN is almost entirely due to the use of pulse-code modulation (PCM) for the transmission of voice signals..

. If the mathematical sums do not match, the modems communicate with each other by resending the missing segments of data. Modems also have special circuitry that allows them to compress digital signals before modulating them and then decompressing them after demodulating the si..

A computer performs its tasks by turning on and off a series of electronic switches represented by the numerical digits of 0 and 1. A 0 is the code for off, and a 1 is the code for on. Combinations of these digital codes represent text, computer commands, and graphics inside the..

A digital message is an ordered sequence of symbols selected from a finite set of discrete elements. Examples of digital messages are: (i) letters printed on this page (ii) listing of hourly temperature readings (iii) the keys you press at a computer terminal. Whether the messa..