Chapter 9 Communications Circuits Circuit A Point-to-Point Circuit A C Circuit Host B D Multipoint(Multidrop) circuit Figure 9-2 Types of circuits with nodes A, B, C, D, and the host computer. www.gxmu.edu.cn
Figure 9-2 Types of circuits with nodes A, B, C, D, and the host computer. www.gxmu.edu.cn Chapter 9 Communications Circuits
Chapter 9 Communications Circuits 9.4.2 Multipoint Circuits A circuit that connects more than two points is called a multipoint circuit or multi-drop circuit. 9.4.3 Tw0-wire and Four-wire Circuits Four-wire circuits are preferable to two wire circuit for data transmission because they can carry communications in both directions simultaneously without employing any special multiplexing techniques www.gxmu.edu.cn
9.4.2 Multipoint Circuits A circuit that connects more than two points is called a multipoint circuit or multi-drop circuit. 9.4.3 Two-wire and Four-wire Circuits Four-wire circuits are preferable to two wire circuit for data transmission because they can carry communications in both directions simultaneously without employing any special multiplexing techniques. www.gxmu.edu.cn Chapter 9 Communications Circuits
Chapter 9 Communications Circuits 9.4.4 Analog Circuits A modem converts a signal from digital to analog mode for transmission on an analog circuit, and back to digital mode at the receiving end 9.4.5 Digital circuits A DSU/CSU provides the signal timing and shaping interface between a dte and a digital circuit www.gxmu.edu.cn
9.4.4 Analog Circuits A modem converts a signal from digital to analog mode for transmission on an analog circuit, and back to digital mode at the receiving end. 9.4.5 Digital Circuits A DSU/CSU provides the signal timing and shaping interface between a DTE and a digital circuit. www.gxmu.edu.cn Chapter 9 Communications Circuits
Chapter 9 Communications Circuits An amplifier takes the input signal and produces an exact replica(including noise and distortion) at a higher level on the output Analog signal Leaving Source Source Amplified signal After Transmission, Showing Still Distorted Attenuation and Distortion Amplifier Figure 9-3 Amplification of an analog signal www.gxmu.edu.cn
Figure 9-3 Amplification of an analog signal. An amplifier takes the input signal and produces an exact replica (including noise and distortion) at a higher level on the output. www.gxmu.edu.cn Chapter 9 Communications Circuits
Chapter 9 Communications Circuits a repeater regenerates the input signal so that its output is clean and free of distortion and noise. Digital Signal Leaving source Source After Transmission Showing Attenuation Regenerated and Distortion Signal repeater Figure 9-4 Regeneration of a digital signal www.gxmu.edu.cn
Figure 9-4 Regeneration of a digital signal. A repeater regenerates the input signal so that its output is clean and free of distortion and noise. www.gxmu.edu.cn Chapter 9 Communications Circuits