Radio-electronic devices and telecommunication means

Telecommunication. Basic Elements| A telecommunication system consists of three basic elements: a transmitter that takes information and converts it to a signal; a transmission medium that carries the signal; and, a receiver that receives the signal and converts it back into....

Telephone| Optical fibre provides cheaper bandwidth for long distance communication. In an analogue telephone network, the caller is connected to the person he wants to talk to by switches at various telephone exchanges. The switches form an electrical connection between the two users and the setting of these switches is determined electronically when the caller dials the number. Once the connection is...

Digital television standards| In a broadcast system, a central high-powered broadcast tower transmits a high-frequency electromagnetic wave to numerous low-powered receivers. The high-frequency wave sent by the tower is modulated with a signal containing visual or audio information. The antenna of the receiver is then tuned so as to pick up the high-frequency wave and a demodulator is used to retrieve ....

The Internet| The Internet is a worldwide network of computers and computer networks that can communicate with each other using the Internet Protocol. Any computer on the Internet has a unique IP address that can be used by other computers to route information to it. Hence, any computer on the Internet can send a message to any other computer using its IP address. These messages carry with ...

Local area networks| Despite the growth of the Internet, the characteristics of local area networks (computer networks that run at most a few kilometres) remain distinct. This is because networks on this scale do not require all the features associated with larger networks and are often more...

What is MPEG?| MPEG (Moving Picture Experts Group) is an International Standards Organization (ISO) group which sets standards for compressing and storing video, audio, and animation in digital form. Moving Picture Experts Group's first meeting was in...

What is a DVD-recorder?| The best way to understand DVD-recorders is to compare them with VCRs. They are similar both in shape, function and features. You can say about a DVD recorder that it's an optical disk recorder that uses a laser beam to write media on a blank DVD. Usually the term of DVD recorder is applied to standalone units that are used in home theater systems, in studios, etc, but there are other types of DVD recorders and...

How many types of mobile telephone systems are there?| The main mobile telephone systems in the last twenty five years have been: 1981 Nordic Mobile Telephone (NMT); 1983 Advanced Mobile Phone System (AMPS); 1985 Total Access Communication System (TACS); 1991 American Digital Cellular (ADC); 1991 Global System for Mobile Communication (GSM); 1992 Digital Cellular System (DCS); 1994 Japanese Personal Digital Cellular (PDC); 1995 Personal Communications Service (PCS)...

What is DVI?| DVI (Digital Video Interface) is a video connector designed by the Digital Display Working Group (DDWG), aimed at maximizing the picture quality of digital display devices such as digital projectors and LCD screens.Previous standards such as Video Graphics Array (VGA) were designed exclusively for CRT-based devices and ...

Fiber optic cable advantages| Speed: Fiber optic networks operate at high speeds – up into gigabits; bandwidth: large carrying capacity; distance: signals can be transmitted further without needing to be "refreshed" or strengthened; resistance: greater resistance to electromagnetic noise such as radios, motors or other nearby cables; maintenance: fiber optic cables costs much less to...