Office Management project on Transmission Medium

Contents: What is transmission medium? Types of transmission medium. Types of guided medium. Types of unguided transmission medium. Which one is best in guided? Difference between guided and unguided.

TRANSMISSION MEDIUM Transmission medium is a physical path between sender and receiver. when we want to transmit data a medium is needed, that is called transmission medium.

TYPES OF TRANSMISSION MEDIUM 1. GUIDED MEDIUM: in guided transmission medium signals are guided along the solid transmission medium such as twisted pair, coaxial cable fiber optic. 2. UNGUIDED MEDIUM: in unguided transmission medium signals are transmitted through air and outer space such as radio waves. it us also called wireless.

TYPES OF GUIDED TRANSMISSION MEDIUM 1. TWISTED PAIR 2. COAXIAL CABLE 3. FIBER OPTIC

TWISTED PAIR A twisted pair cable consists of two insulated copper wire about 1 mm thick. The wires are twisted together in a helical form just like a DNA molecules. Twisting is done because two parallel wire constitute a fine antenna.when wires are twisted the view from different twist cancel out so the wires radiates less effectively. The most common application of the twisted pair is the telephone system. Twisted pair can be used for either analog or digital signals.

COAXIAL CABLE Another type of transmission medium is coaxial cable. It consists of a stiff copper wire as a core, surrounded by an insulated material. The insulated is encased by a cylindrical conductor. the outer conductor is covered in a protective plastic sheet. Two kinds of coaxial cables are widely used one is 50 ohm and another is 75 ohm. 50 ohm is commonly used for digital transmission. 75 ohm is used for analog transmission.

FIBER OPTIC Optical fiber is widely used as transmission medium. It is thin flexible medium through which signals are transmitted in the form of light ray. Optical fiber is cylindrical in shape which has three parts, core, cladding and jacket. Core is made of the plastic & glass which is very thin. Core is surrounded by the cladding and cladding is surrounded by jacket. Data transmission through optical fiber in the form of light. A pulse of light indicates 1 bit and absence of light indicates 0 bit.

WHICH ONE IS BEST IN GUIDED? Fiber optic transmission medium is better than coaxial cable and twisted pair cable. Fiber optic is easy to usable because it is based on presence of light.

TYPES OF UNGUIDED TRANSMISSION MEDIUM 1. TERRESTRIAL MICROWAVE 2. BROADCAST RADIO

TERRESTRIAL MICROWAVE Terrestrial microwave has earth based transmitters and receivers. The frequency used in this transmission is the low ghz range. Microwave transmission typically used a parabolic antenna that produce a narrow, highly directional signal. A similar antenna at the receiving sight is sensitive to the signals only within a narrow focus. Transmitters and receivers are highly focused, they must be adjusted carefully.

TERRESTRIAL MICROWAVE

BROADCAST RADIO Broadcast radio uses radio in omni directional. There are no need of the dish antenna and no need of the aligned antenna. Radio waves are easy to generate and can easily travel a long distance. Radio waves can penetrate building so these are widely used in indoor and outdoor communications. Radio wave have frequency range from 3 khz to 300 ghz.

BROADCAST RADIO

Range of radio waves very low frequency 3 khz to 30 khz Low frequency 30 khz to 300 khz Middle frequency 300 khz to 3 mhz High frequency 3 mhz to 30 mhz Very high frequency 30 mhz to 300 mhz Ultra high frequency 300 mhz to 3 ghz Super high frequency 3 ghz to 30 ghz Extremely high frequency 30 ghz to 300 ghz

DIFFERENCE BETWEEN GUIDED AND UNGUIDED Guided medium is used only for shorted distance while unguided is used for larger distance. Guided medium can not penetrate building while unguided can easily penetrate it.

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submitted by: varsha verma mca 1 st sem