chapter 8 questions
Chapter 7 Questions:
3. Compare and contrast the two types of antennas.
- omnidirectional antennas: the antenna transmits in all directions simultaneously. One common omnidirectional antenna is the dipole antenna (nicknamed the “rubber duck” because of its flexibility); omnidirectional antennas transmit in all directions, both horizontally and vertically. The signal goes in all directions, as well as up and down, although there is often a small dead spot with no signal that is a very small area directly above the antenna.
- directional antenna: As the name suggests, a directional antenna projects a signal only in one direction. Because the signal is concentrated in a narrower, focused area, the signal is stronger and therefore will carry farther than the signal from an AP using an omnidirectional antenna. Directional antennas are most often used on the inside of an exterior wall of a building, pointing to the inside of the building. This keeps the signal inside the building (to reduce security issues) and also has the benefit of increasing the range of the AP.
7. How does 802.11g differ from 802.11b and 802.11a?
- 802.11a: provides high speed wireless networking in the 5 GHz range. It is a legacy technology, and no new products are being developed; but some firms still use it. It provides eight channels for indoor use in the United States (plus one channel for outdoor use). The 802.11a standard provides for more or fewer channels in other parts of the world where the radio frequency spectrum regulation is different.
- 802.11g: provides high speed wireless networking in the 2.4 GHz range. It will soon be replaced by 802.11n, so it too will be a legacy technology within a year or two. It provides three channels for indoor use in the United States. The 802.11g standards provides for more or fewer channels in other parts of the world whose radio frequency spectrum regulation is different. 802.11g was designed to take the best of both the 802.11a and 802.11b
3. Compare and contrast the two types of antennas.
- omnidirectional antennas: the antenna transmits in all directions simultaneously. One common omnidirectional antenna is the dipole antenna (nicknamed the “rubber duck” because of its flexibility); omnidirectional antennas transmit in all directions, both horizontally and vertically. The signal goes in all directions, as well as up and down, although there is often a small dead spot with no signal that is a very small area directly above the antenna.
- directional antenna: As the name suggests, a directional antenna projects a signal only in one direction. Because the signal is concentrated in a narrower, focused area, the signal is stronger and therefore will carry farther than the signal from an AP using an omnidirectional antenna. Directional antennas are most often used on the inside of an exterior wall of a building, pointing to the inside of the building. This keeps the signal inside the building (to reduce security issues) and also has the benefit of increasing the range of the AP.
7. How does 802.11g differ from 802.11b and 802.11a?
- 802.11a: provides high speed wireless networking in the 5 GHz range. It is a legacy technology, and no new products are being developed; but some firms still use it. It provides eight channels for indoor use in the United States (plus one channel for outdoor use). The 802.11a standard provides for more or fewer channels in other parts of the world where the radio frequency spectrum regulation is different.
- 802.11g: provides high speed wireless networking in the 2.4 GHz range. It will soon be replaced by 802.11n, so it too will be a legacy technology within a year or two. It provides three channels for indoor use in the United States. The 802.11g standards provides for more or fewer channels in other parts of the world whose radio frequency spectrum regulation is different. 802.11g was designed to take the best of both the 802.11a and 802.11b