Question

In this assignment, you will work individually to answer the following review questions: List the IEEE 802.11 b/a/g/n/ac standards in order of lowest transmission speed to highest transmission speed * At what frequency ranges do the IEEE 802.11 b/a/g/n/ac standards transmit? What is important about these different frequencies? * Your wireless LAN device has just sent a request to send (RTS). What happens next? *In a CSMA/CA+Ack setting, your wireless LAN device has just determined that the signal is clear. What happens next? Your company wants to create a wireless network for the entire office building, which is 10 stories high and the company wants to use 802.11 with a single router per floor. Which service set will they use and why?

Answer 1

IEEE 802.11n: Transmission speeds of 600 Mbps (actual is about 100 Highest -145 Mbps) IEEE 802.11a: Transmission speed of 54 Mbps (actual is about 2) 5 GHz signal IEEE 802.11g: Transmission speed of 54 Mbps (actual is about V2) Lowest 2.4-GHz signal IEEE 802.11b: Transmission speed of 11 Mbps (actual is about 12)

2.At what frequency ranges do the IEEE 802.11b/a/g/n standards transmit? What is important about these different frequencies?

ANS)

IEEE 802.11 wireless standards are known as Wi-Fi or wireless fidelity. IEEE 802.11b ratified inSeptember 1999; can theoretically transmit data at a rate of 11 Mbps using 2.4-GHz frequencies. IEEE 802.11g ratified in 2002; can theoretically transmit data at a rate of 54 Mbps using 2.4-GHz frequencies. IEEE 802.11a ratified in 2002; can theoretically transmit data at a rate of 54 Mbps using 5-GHz frequencies (Data Communications and Computer Network p. 211). IEEE 802.11n introduced in 2004; can theoretically transmit data at a rate of 600 Mbps using both 2.4-GHz and 5-GHz frequencies (radio-electronics.com). Multiple input multiple output (MIMO) technique allows IEEE 802.11n to be capable of using both frequencies. MIMO both the mobile device and access point have multiple different accessibilities to smart antennae; this ensures thatsignal interference and reflections are kept at minimum (Data Communications and Computer Network p. 211). The important concept behind the different frequencies in Wi-Fi IEEE 802.11b/a/g/n standards is data transition and distance range. IEEE 802.11b/g transmits data at a range of 45 meters inside and 90 meters outdoors. IEEE 802.11a transmits data at a range of 1/3 of IEEE 802.11b/g. IEEE 802.11n is capable of transmitting data indoors up to 90 meters and 279 meters outdoors (Data Communications and Computer Network p. 211-212). Cost is a factor that many organizations consider, because if you want high data transfer rate; you are going to utilize more access points and need a secure network. The organization has to consider the contents of the building and determine if data will be able to be transmitted and have Wi-Fi access.

5.Your company wants to create a wireless network for the entire office building. The building is 10 stories high, and the company wants to incorporate IEEE 802.11a by placing one access point on the tenth floor. Will this layout work? Explain.

ANS)

  The company needs to revise their decision into more depth. IEEE 802.11a standards are able to transmit data indoors at 15 meters; which is one third of IEEE 802.11b/g standards. Being capable to transmit data doesn’t necessarily mean that is going to happen. The shorter wavelength of IEEE 802.11a 5 GHz has predicaments traveling through walls, floors, and furniture (Data Communications and Computer Network p. 211-212). The layout would not work because of the complexity of a 10 stories high building for the company. All of the components inside the complex will prevent data frequency transitions. If the company wants to incorporate IEEE 802.11a, it would need more access points at better located settings. If they insist of only using one access point; there vest utility of IEEE 802.11a access point will be in the fifth floor.