Communication Networks Review Question/Answer - Lecture 11Review Question Virtual Channel and Virtual Path Q:-What is the difference between a virtual channel and a virtual path? Ans:-A virtual channel is a logical connection similar to virtual circuit in X.25 or a logical channel in frame relay. In ATM, virtual channels that have the same endpoints can be grouped into virtual paths. All the circuits ...
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Signal Encodin Techniques Review/Recap - Lecture 20Q:- A microwave transmitter has an output of 0.1 W at 2 GHz. Assume that this transmitter is used in a microwave communication system where the transmitting and receiving antennas are parabolas, each 1 .2 m in diameter. What is the gain of each antenna in decibels? Taking into account antenna gain, what is the effective radiated power of the tran...
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Communication Networks - Lecture 10QoS Enforcement Traffic contract Traffic shaping Traffic policing Summary Circuit Switching and Packet Switching; the backbone of Wireless Communication Infrastructure Pros and Cons of Ckt Switching and Pkt Switching Requirement of Convergence of Voice, Video and Data Services and Merger of Ckt. Switching And Packet Switching ATM Flexibilit...
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Encoding Techniques - Lecture 19Differential Manchester Encoding midbit transition is only used for clocking transition at start of bit period representing 0 no transition at start of bit period representing 1 this is a differential encoding scheme used by IEEE 802.5 Summary Signal encoding techniques digital data, digital signal NRZ, multilevel binary, biphase, modulat...
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Signal Encoding Techniques - Lecture 18Reasons for Growth of Digital Techniques Growth in popularity of digital techniques for sending analog data Repeaters are used instead of amplifiers No additive noise TDM is used instead of FDM No intermodulation noise Conversion to digital signaling allows use of more efficient digital switching techniques Summary Layered Position Data an...
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Communication Networks - Lecture 9Modern Cellular Standards First generation (1G) systems (analog) 1979: NTT (Japan), FDMA, FM, 25 kHz channels, 870-940 MHz) 1981: NMT (Sweden and Norway), FDMA, FM, 25 kHz, 450-470 MHz 1983: AMPS (US), FDMA, FM, 30 kHz channels, 824-894 MHz 1985: TACS (Europe), FDMA, FM, 25 kHz channels, 900 MHz Second generation (2G) systems (digital) Supp...
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Transmission Fundamentals Recap Questions/Solutions - Lecture 8Summary: Recap of Transmission Fundamentals via Questions and their Solutions Frequency Period Relationship Representation of a signal by sinusoids Frequency Wavelength Relationship Amplitude, Frequency and Phase Decomposition of a Signal Sinusoidal Signal Period Periodicity in Case of Linear Combination of two Signals Signal Harmonics Elim...
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Antennas and Propagation Review/Recap - Lecture 17Q/A Q:- Suppose a transmitter produces 50 W of power. Express the transmit power in units of dBm and dBW. If the transmitter's power is applied to a unity gain antenna with a 900-MHz carrier frequency, what is the received power in dBm at a free space distance of 100 m? Repeat (b) for a distance of 10 km. Repeat (c) but assume a receiver anten...
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Transmission Fundamentals Review Q/A - Lecture 7Synchronous TDM: Review Question Q: Explain how synchronous time division multiplexing (TDM) works Ans:A synchronous time division multiplexer interleaves bits from each signal and takes turns transmitting bits from each of the signals in a round-robin fashion. Summary: Review Q/A with Discussion Transmission Media Guided Unguided Media Trans...
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Antennas and Propagation…. - Lecture 16Q:- It has been studied that if a source of electromagnetic energy is placed at the focus of the paraboloid, and if the paraboloid is a reflecting surface, then the wave will bounce back in lines parallel to the axis of the paraboloid. To demonstrate this, consider the parabola y2= 2px shown in Figure. Let P(x1, y1 ) be a point on the parabola and ...
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