NET 211 - Wireless Networking

Review for First Test

The following questions are provided to help you study for the first test. Do not expect to see these exact questions on the test.

  1. What are some advantages to using wireless networking in various scenarios, as explained in the text?

  2. Why are wireless networking devices sometimes affected by unrelated devices like microwave ovens?

  3. What are some of the acronyms in the text that refer to networks of different sizes? What is the relative ranking (by size) of those network types?

  4. What is the name of the US federal agency concerned with wireless transmissions?

  5. What is the difference between the ISO and the ITU-R, with regard to wireless concerns?

  6. What is the IEEE and what has it done for wireless technology?

  7. What benefit does the Wi-Fi Alliance provide to wireless technology consumers?

  8. Why is competition between wireless vendors a benefit to wireless technology consumers?

  9. Explain why competition between vendors would be a problem without interoperability standards.

  10. Where do de jure and de facto standards usually come from?

  11. What are the two spectra that were originally described in the 802.11 standard of 1997?

  12. What typically happens to the bandwidth available to stations on most 802.11 networks as they move farther and farther away from their access points?

  13. What was the main limitation on the 802.11a standard that led to development of other standards?

  14. What was the main limitation on the 802.11b standard that led to development of other standards?

  15. Why is it likely that a device meant to use 802.11g could fall back to use 802.11b, but not 802.11a?

  16. What is an Access Point, and why do we need them?

  17. How are Autonomous and Lightweight Access Points different from regular ones?

  18. What kind of situation would make having Mesh Access Points a good idea?

  19. What is a possible power alternative when there is no electrical outlet near the best place to hang an AP? What has to be true to use that option?

  20. How are sound waves like light waves? How are they different?

  21. Describe the basic pattern of a sine wave, using a graph for reference.

  22. What is the relationship between frequency and wavelength of electromagnetic waves?

  23. What is the scientific unit that means one cycle per second? How about one million cycles per second?

  24. Compare a sine wave to a cosine wave, regarding their phases.

  25. According to the graphic on page 88, what band of the EM spectrum has slightly longer wavelengths than visible light? What band comes after that one, in terms of increasing wavelength? And after that one?

  26. Explain the difference between an analog signal and a digital signal. Which is preferred for data transmissions?

  27. What terms are used for the three classic types of digital signal modulation?

  28. What is the formula for watts? What is the formula for voltage?

  29. What is a logarithm? How does it help to understand what a decibel is?

  30. If we measure a signal at 50 milliwatts, and the noise in the area at 30 milliwatts, what is the signal to noise ratio, and what is the proper decibel notation for it?

  31. What is the rule of 10s and the rule of 3s in RF math?

  32. What are some materials that absorb RF signals?

  33. What kind of material would we expect to reflect RF signals?

  34. What kind of material should produce RF scattering? Why do we care about that?

  35. What is nulling? What would cause it?

  36. How can there be natural amplification of a signal?

  37. How does an antenna "create" an electric signal in a radio receiver?

  38. What kind of antenna would we call a bare wire?

  39. What is the benefit of having a ground plane?

  40. What is an unintentional radiator?

  41. What is an isotropic radiator? How is that concept used in Decibels Isotropic?

  42. What is the conversion between decibels isotropic and decibels dipole?

  43. What does it mean to have antenna diversity?

  44. How is a semi-directional antenna different from highly-directional antenna? What is the purpose of choosing either type?


  45. What is an azimuth chart? How is it different from an elevation chart? Why do we need at least these two charts to understand an antenna?

  46. Which practical 802 version introduced MIMO? How is it different from antenna diversity?

  47. Which kind of attenuators are allowed by FCC regulations? What kind of device is an attenuator the opposite of?

  48. What is a fade margin? What else is it called?