Give a brief definition of a Computer Network. List 3 benefits or advantages of Computer Networks....

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Give a brief definition of a Computer Network. List 3 benefits or advantages of Computer Networks. (5) b) Computer networks are divided into several layers, for instance, ISO's OSI has seven layers, and the Internet's TCP/IP has only 4 layers. i) ii) Explain the open systems concept (in the context of the OSI model) State 3 reasons why the layered structure is used to describe computer networks. [3] c) Operations of similar functionality can be performed at different layers of a protocol stack. At which layers are the following done? [5] i) Routing ii) Multiplexing iii) Error detection and correction iv) Flow control and framing v) Signalling/Data Encoding d) Explain why digital rather than analogue transmission is favoured in modern communications systems. Question 2 a) Explain the differences between Omnidirectional and Directional antennas b) State 3 problems that can prevent signals from being accurately transmitted through a transmission medium. [3] c) Each channel of the cable TV has a bandwidth of 3MHz. Assume that the signal-to-noise ratio for each channel is -30dB. i). When we use this cable TV channel to transfer digital data, what is the channel capacity? [5] Question 3 a) State any 4 factors you would consider when comparing or selecting transmission media. [4] b) Describe the fundamental differences between cross over and straight through twisted pair cables? c) What are the differences between Coaxial cables and Fibre Optic cables? (4) (8) d) List 3 reasons why wireless communication can be favoured in placed of guided communication e) What is the difference between and IP address and a MAC address? [4] ii). Assuming the channel is noiseless, how many signal/ voltage levels would be need to achieve the capacity you got in i). (5) d) Given that the speed of light is 3x10 m/s and a satellite is at a geosynchronous orbit. How long would it take for a signal to go from the earth to the satellite? Assume that the distance of the satellite from the earth is 35 863km. [5] 호 [3] (4) (5) [2] Give a brief definition of a Computer Network. List 3 benefits or advantages of Computer Networks. (5) b) Computer networks are divided into several layers, for instance, ISO's OSI has seven layers, and the Internet's TCP/IP has only 4 layers. i) ii) Explain the open systems concept (in the context of the OSI model) State 3 reasons why the layered structure is used to describe computer networks. [3] c) Operations of similar functionality can be performed at different layers of a protocol stack. At which layers are the following done? [5] i) Routing ii) Multiplexing iii) Error detection and correction iv) Flow control and framing v) Signalling/Data Encoding d) Explain why digital rather than analogue transmission is favoured in modern communications systems. Question 2 a) Explain the differences between Omnidirectional and Directional antennas b) State 3 problems that can prevent signals from being accurately transmitted through a transmission medium. [3] c) Each channel of the cable TV has a bandwidth of 3MHz. Assume that the signal-to-noise ratio for each channel is -30dB. i). When we use this cable TV channel to transfer digital data, what is the channel capacity? [5] Question 3 a) State any 4 factors you would consider when comparing or selecting transmission media. [4] b) Describe the fundamental differences between cross over and straight through twisted pair cables? c) What are the differences between Coaxial cables and Fibre Optic cables? (4) (8) d) List 3 reasons why wireless communication can be favoured in placed of guided communication e) What is the difference between and IP address and a MAC address? [4] ii). Assuming the channel is noiseless, how many signal/ voltage levels would be need to achieve the capacity you got in i). (5) d) Given that the speed of light is 3x10 m/s and a satellite is at a geosynchronous orbit. How long would it take for a signal to go from the earth to the satellite? Assume that the distance of the satellite from the earth is 35 863km. [5] 호 [3] (4) (5) [2]

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Question 1 a a computer network is a group of interconnected computers that can communicate with each other and share resources such as files printers and internet connections Computer networks can be ... View the full answer