Ch:2 The Physical Layer
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The document discusses various methods for transmitting data through communication networks, including guided transmission media like twisted pair cables, coaxial cables, fiber optics, and wireless transmission via radio waves, microwaves, infrared, light, or communication satellites. It covers theoretical concepts like Fourier analysis, bandwidth-limited signals, and Shannon's formula for channel capacity. Different transmission media are compared in terms of their bandwidth, attenuation characteristics, and use cases for data transmission.
Ch:2 The Physical Layer
- 1. The Physical Layer Chapter 2 2.1 - 2.4 Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 2. Theoretical Basis for Data Communication • Fourier analysis • Bandwidth-limited signals • Maximum data rate of a channel Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 3. Fourier Analysis • We model the behavior of variation of voltage or current with mathematical functions • Fourier series is used • Function reconstructed with Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 4. Bandwidth-Limited Signals (1) A binary signal and its root-mean-square Fourier amplitudes. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 5. Bandwidth-Limited Signals (2) (b)-(e) Successive approximations to the original signal. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 6. Bandwidth-Limited Signals (3) (b)-(e) Successive approximations to the original signal. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 7. Bandwidth-Limited Signals (4) (b)-(e) Successive approximations to the original signal. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 8. Bandwidth-Limited Signals (5) (b)-(e) Successive approximations to the original signal. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 9. Bandwidth-Limited Signals (6) Relation between data rate and harmonics for our example. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 10. The Maximum Data Rate of a Channel • Nyquist’s theorem • Shannon’s formula for capacity of a noisy channel Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 11. Guided Transmission Media • Magnetic media • Twisted pairs • Coaxial cable • Power lines • Fiber optics Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 12. Magnetic Media • Write data onto magnetic media • Disks • Tapes • Data transmission speed • Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 13. Twisted Pairs Category 5 UTP cable with four twisted pairs Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 14. Coaxial Cable A coaxial cable Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 15. Power Lines A network that uses household electrical wiring. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 16. Fiber Optics (1) Three examples of a light ray from inside a silica fiber impinging on the air/silica boundary at different angles. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 17. Fiber Optics (2) Light trapped by total internal reflection. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 18. Transmission of Light Through Fiber Attenuation of light through fiber in the infrared region Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 19. Fiber Cables (1) Views of a fiber cable Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 20. Fiber Cables (2) A comparison of semiconductor diodes and LEDs as light sources Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 21. Wireless Transmission • The Electromagnetic Spectrum • Radio Transmission • Microwave Transmission • Infrared Transmission • Light Transmission Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 22. The Electromagnetic Spectrum (1) The electromagnetic spectrum and its uses for communication Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 23. The Electromagnetic Spectrum (2) Spread spectrum and ultra-wideband (UWB) communication Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 24. Radio Transmission (1) In the VLF, LF, and MF bands, radio waves follow the curvature of the earth Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 25. Radio Transmission (2) In the HF band, they bounce off the ionosphere. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 26. The Politics of the Electromagnetic Spectrum ISM and U-NII bands used in the United States by wireless devices Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 27. Light Transmission Convection currents can interfere with laser communication systems. A bidirectional system with two lasers is pictured here. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 28. Communication Satellites • Geostationary Satellites • Medium-Earth Orbit Satellites • Low-Earth Orbit Satellites • Satellites Versus Fiber Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 29. Communication Satellites Communication satellites, some properties, including: altitude above earth, round-trip delay time, number of satellites for global coverage. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 30. Geostationary Satellites (1) The principal satellite bands Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 31. Geostationary Satellites (2) VSATs using a hub. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 32. Low-Earth Orbit Satellites (1) The Iridium satellites form six necklaces around the earth. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 33. Low-Earth Orbit Satellites (2) Relaying in space. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011
- 34. Low-Earth Orbit Satellites (3) Relaying on the ground Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011