Shruti Speak's

Transmission Media    Usually all computer communication involves encoding data in a form of energy and sending the energy across a transmission medium. In other words the physical media through which we can transmit data from one point to another is called a transmission media. The transmission of the data can be using electromagnetic signals which consist of both electrical and magnetic fields conjugating with each other.    Transmission media is divided into following two broad categories: 1.    Guided/Wired Media 2.Unguided/Wireless Media 1.    Guided Media: a) Twisted Pair Cable     The twisted pair cable consists of two insulated wires arranged in a regular spiral pattern or cable made by intertwining two separate insulated wires. It is further of two types: Unshielded Twisted Pair Cables (UTP): UTP cables as the name suggests have no protection against interference. The performance of UTP is often gets degraded. However UTP   cable   is the most common ca

Type Of connections for Networking(Cont.) Based on Scale , Computer networks can be classified into Local Area (LAN), Metropolitan Area Network (MAN) and Wide Area Networks (WAN). a) Local Area Network (LAN): LAN stands for Local Area Network and is usually privately owned. It spans short distances and connects relatively a small number of computers. It is generally used to link the devices in a single office, building or campus usually up to few kilometers in size. The main use of LAN is to share resources and to exchange information. LAN can be distinguished from other kinds of networks by three categories: their size, transmission technology and topology. In LANs the worst-case transmission time is bounded which means they are restricted in size. It simplifies network management and is more reliable than MAN and WAN. b) Metropolitan Area Network (MAN): MAN stands for Metropolitan Area Network. It spans a small city or a town and it usually covers the entire cit

Type Of Connections for Networking Based on   transmission technology , Computer networks can be broadly classified as follows:  a) Broadcast networks: This network has a single communication channel which is shared by all other machines present on the network. All the machines on the network receive short messages known as packets and the address field within the packet specifies the intended recipient. The machine first checks the address field of the packet when it receives it and only if the packet is intended for itself, it processes it otherwise it simply ignores it. b) Point to Point Networks:           This network provides a dedicated link between two devices. Mostly these connections use an actual length of wire or cables to connect the two ends. In point to point Networks usually the end devices which communicate are referred as stations where as the switching devices are known as nodes.

What is a NETWORK? A set of devices (commonly known as nodes) which is connected by a communication link is known as a network. A node is generally a device (such as computer, printer etc.) which can send and receive data generated by other nodes on the network. A network must be able to meet certain important characteristics such as performance, reliability and security .   Need For Networking To share computer files: Networks provide a very effective way to share files with different users. Like in order to share a common file with different departments of an organization, we can place the file on the network so that it can be used by all the departments. To share computer peripheral: Network enables us to share certain computer devices with one another which may be very costly/expensive. E.g.-Laser printer etc. To enable communication: Networks allow unlike computers to communication with each other. A computer with different operating syste

Growth Of Computer Networks Due to the explosive growth of computer networks, computer communication has become an essential part of our infrastructure. Nowadays the concept of networking in followed in every aspect of business which includes advertising, production, planning etc. Many corporations have multiple networks; schools as well as many colleges also make use of computer networks to provide students and teachers with instantaneous access to information. Networking  can also be stated as the practice of linking two or more computing devices together in order to communicate and share data. Usually networks are built with a mix of computer hardware and computer software. The growth of networking has an economic impact as well as an entire industry has emerged that develops networking technologies, products and services. Computer networking has also produced a strong demand in jobs for people with networking expertise due to the growing popularity

MICROWAVE :- These  are a form of electromagnetic radiation with wavelengths ranging from as long as one meter to as short as one millimeter, which is equal to the frequencies between 300 MHz (0.3 GHz) and 300 GHz. This definition includes both UHF and EHF both are millimeter waves, and various sources use different boundaries. In every case, microwave includes the entire SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum, with RF engineering often putting the lower boundary at 1 GHz (30 cm), and the upper around 100 GHz (3 mm).The prefix "micro-" in "microwave" is not meant to suggest a wavelength in the micrometer range. It indicates that microwaves are "small" compared to waves used in typical radio broadcasting, in that they have shorter wavelengths. The boundaries between far infrared light, terahertz radiation, microwaves, and ultra-high-frequency radio waves are arbitrary and are used variously between different fields of study.                     

INFRARED (IR) :- This  light is electromagnetic radiations with longer wavelengths than those of visible light, extending from the nominal red edge of the visible spectrum at 700 nanometer (nm) to 1 mm. Wavelengths of these ra ys corresponds to a frequency range of approximately 430 THZ down to 300 GHz, and includes most of the thermal radiation emitted by objects near room temperature. Infrared light is emitted or absorbed by molecules when they change their rational-vibrations movements. It was first discovered in 1800 by astronomer William Herschel. Slightly more than half of the energy from the Sun arrives on Earth in the form of infrared radiation. The balance between absorbed and emitted infrared radiation has a critical effect on Earth's climate. History of Infrared:- The discovery of this radiation is ascribed to William Herschel, the astronomer, in the early 19th century. He published his results in 1800 before the Royal Society of London. He used a prism to refract li