Transcript Slide 1
Computer Science Project Communication and Network concepts • Transmission media twisted pair cable coaxial cables optical fibers Microwave Radio wave Satellite • Data communication terminologies. • Transmission media is also known as communication channels. • They are the cables that connect two or mare workstations. • Two categories: 1.guided media-include cables. 2.unguided media-include waves through air, water or vacuum. Twisted pair cable • Common form of wiring in data communication application. • Voice grade medium(VGM)-basis for telephone wiring. • Consists of two identical wires wrapped together in a double helix. • Twisting of wires reduces crosstalk • Unshielded twisted pair cable(UTP) Shielded twisted pair cable(STP) Simple Easy install & maintain Inexpensive Advantages Physically flexible Easily connectable Low weight • Incapable of carrying signal over long distances due to high attenuation. • Low bandwidth capabilities-unsuitable for broadband applications. • max. data rates = 1 Mbps- without conditioning 10 Mbps with conditioning •Consists of a solid wire core surrounded by one or more foil or wire shields, each separated by a insulator. •Inner core- carries signal •Shield –provides the ground •Suitable for high speed communication & widely used for TV signals. Types •Thicknet-can be upto 500 meters long. They are thicker than thinnet •Thinnet-using this cable max. distance of 185 meters can be joined. Advantages • Can be used as the basis for a shared cable network. • Can be used for broadband transmission. • Offer higher bandwidths- upto 400 MBPS. Disadvantage •Expensive. •Not compatible with twisted pair cable. •Consists of thin strands of glass or glass like material. •Light source –LEDs or laser diodes(LDs). •Bandwidth is very high. •Fiber cable consists of three pieces: core Cladding Protective coating •Types Single node Multi node • Immune to electrical and magnetic interference. • Highly suitable for harsh industrial environments. • Guarantees secure transmission and high transmission capacity. • Can be used for broadband transmission where several channels are handled in parallel. • • • • • Installation problem- very fragile Connection looses are common problems. Cables are more difficult to solder. Light can reach the receiver out of phase. Virtually impossible to tap due to noise immunity. • Most expensive. Type Type Sub type Max.Seg ment Length Bandwidth supported installa cost tion Interferen ce Twisted UTP 100 mts 100 Mbps Easy Cheapest High pair cable STP 100 mts 500 Mbps moder moderate moderate ate Coaxial Thinnet 185 mts 10 Mbps Easy Cheap Moderate cable Thicknet 500 mts 10 Mbps hard moderate Low Fiber Multinude 2 kms 100 Mbps Very hard Expensive None optic Singlenode 100 kms 2 Gbps Expensive None cable Very hard Guided media The different types of guided media are : 1. Microwave 2. Radio wave 3. Satellite The different types of other unguided media are : 1. Infrared 2. Laser cheaper No use of cables Micro wave advantages Ability to communicate through oceans Freedom from acquisition rights and other governmental requirements Ease of communication Microwave disadvantages Radio wave advantages Offers mobility disadvantages Cheaper Insecure communication Offers ease of communication Freedom from land acquisition rights Reduce signal strength Area coverage is large High investment costs Maintenance easy Satellites advantages High atmospheric large Can cover areas of the earth loses Disadvantag es sparsely Useful in populated areas c loses Satellite disadvantages Over crowding of bandwidths High investments cost High atmospheric losses other unguided media Infrared It uses infrared lights Used in everyday life like remotes , automotive garage doors and wireless speaker Common in pda’s Laser It is a line of sight transmission Point to point transmission It can be adversely affected by weather A channel is the medium which is used to carry information or data from one point to another. It refers to the speed at which data transfer is measured. It is generally used to measure the speed of information through a high speed phone lines or modems. Acknowledgement First and foremost, we would like to thank Kiran madam for having given us the opportunity for expressing our ideas through this project. We would also like to thank our friends for their creative ideas without which this would have been incomplete, last but not the least, we would like to thank everyone who directly or indirectly supported us.