data transmission and reception

Telefacsimile's or Fax machines are a must for many businesses around the world. The fax machine however, did not become widely used until the late 1980'..

These are commonly used in power distribution (at low frequencies) and in communications (at high frequencies). Biodiversity is most simply defined as the variety of life and its processes. A transmission line may be defined as a device for transmitting or guiding energy from one point t..

The 'modem' is a contraction of the term modulator-demodulator. It is a conversion that facilitates the transmission and reception of the data over the public switched telephone network (PSTN). The data of interest may be digital signals generated by computer..

Various electrical machines and noises cause amplitude disturbance in the transmission of amplitude-modulated wave. This makes the reception nois..

Need for Frequency Modulation - (i) Various electrical machines and noises cause amplitude disturbance in the transmission of amplitude-modulated wave. This makes the reception noisy. So, there is a need for different type of modulation, which can reduce the noise factor. Freque..

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

Telefacsimile's or Fax machines are a must for many businesses around the world. The fax machine however, did not become widely used until the late 1980's. A fax means basically scanning a page to make an electronic representation of its text or graphics, compresses the data to save ..

Advantages - The advantages associate with digital communication systems include (i) A common format for encoding different kinds of message signals (e.g., speech signal, video signal, computer data, etc.) for the purpose of transmission. (ii) An improved security of message. (i..

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.]..

When a modem first makes a connection, you will hear screeching sounds coming from the modem. These are digital signals coming from the computer to which you are connecting being modulated into audible sounds. The modem sends a higher-pitched tone to represent the digit 1 and a lower-pitched tone t..