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Factors Effecting Channel Capacity The Factors Bandwidth Noise, Error rate affect channel capacity Bandwidth: The bandwidth of the transmitted signal as constrained by the transmitter and the nature of the transmission medium, expressed in cycles per second, or hertz Noise: The average level of noise over the communications path Error rate: ...
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Effective Radiated Power The effective radiated power (ERP or EIRP) is the gain of an antenna (with respect to an isotropic radiator) multiplied by its input power. ERP = input power x antenne gain For example, a highly directional antenna with a gain of 7 has an input power of 1-kW. Its ERP is therefore 7 kW. Summary Electric and Magnetic F...
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TCP UDP Header Length Q:- Why does the TCP header have a header length field while the UDP header does not? Ans:- UDP has a fixed-sized header. The header in TCP is of variable length. Summary Network Layer Functionality Task performed @ Transport Layer Protocol and Protocol Stack Protocol Data Unit Protocol Architecture TCP/IP Stack Lay...
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Time and frequency multiplex Combination of both methods A channel gets a certain frequency band for a certain amount of time Example: GSM Advantages better protection against tapping protection against frequency selective interference but: precise coordination required Code multiplex Each channel has a unique code All channels use the s...
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Infrared Achieved using transceivers that modulate noncoherent infrared light Transceivers must be within line of sight of each other directly or via reflection Does not penetrate walls No licenses required No frequency allocation issues Typical uses: TV remote control One important difference between infrared and microwave transmission is ...
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Transport Layer Recap Q:- What tasks are performed by the transport layer? Isolates messages from lower and upper layers Breaks down message size Monitors quality of communications channel Selects most efficient communication service necessary for a given transmission Transport Layer Concerned with reliable transfer of information between ap...
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Example Consider an example that relates the Nyquist and Shannon formulations. Suppose the spectrum of a channel is between 3 MHz and 4 MHz, and SNRdB = 24dB. So, B = 4 MHz – 3 MHz = 1 MHz SNRdB = 24 dB = 10 log10(SNR) SRN = 251 Using Shannon’s formula, the capacity limit C is: C = 106 x 1og2(1+251) ≈ 8 Mbps. If we want to achieve this l...
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Functions of a Router Provide a link between networks Provide for the routing and delivery of data between processes on end systems attached to different networks Provide these functions in such a way as not to require modifications of the networking architecture of any of the attached subnetworks Network Differences Routers Must Accommodate A...
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Network Simulator 2 ns -2 stands for Network Simulator version 2. ns -2: Is a discrete event simulator for networking research Work at packet level. Provide substantial support to simulate bunch of protocols like TCP, UDP, FTP, HTTP and DSR. Simulate wired and wireless network. Is primarily Unix based but can also be used with Windows via Cy...
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Effective Bandwidth Many signals have an infinite bandwidth, but with most of the energy contained in a relatively narrow band of frequencies. This band is referred to as the effective bandwidth, or just bandwidth. DC component Any periodic waveform with a frequency has three components: A DC component (Also called the average value) A sinusoi...
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