CompTIA®A+ Lab Exercises Exam Notes : identifying Speed Ranges Of 802.11 Standards

5. Identifying speed ranges of 802.11 standards

Description: This lab exercise helps you to know the speed ranges of a 802.11 standards.

Instructions:

1. Different 802.11 standards are given in the column A

2. Various speed ranges of 802.11 standards are given in the column B

3. Match (drag and drop) the standards given on the column A with their speed ranges given on the column B.

speed ranges of 802.11 standards

Solution:

The correct answer is displayed on the left

speed ranges of 802.11 standards solution

Explanation :

802.11a standard provides wireless LAN bandwidth of up to 54Mbps in the 5GHz frequency spectrum. The 802.11a standard also uses orthogonal frequency division multiplexing (OFDM) for encoding rather than FHSS or DSSS.

802.11b standard provides for bandwidths of up to 11 Mbps (with fallback rates of 5.5, 2, and 1 Mbps) in the 2.4G Hz frequency spectrum. This standard is also called Wi-Fi or 802.11 high rates. The 802.11b standard uses only DSSS for data encoding.

802.11g standard provides for bandwidths of 20 Mbps+ in the 2.4 GHz frequency spectrum. This offers a maximum rate of 54 Mbps and is backward compatible with 802.11b.

802.11n : A more recent wireless standard you need to know for the exam is 802.11n. The goal of the 802.11n standard is to significantly increase throughput in both the 2.4 GHz and the 5 GHz frequency range. The baseline goal of the standard was to reach speeds of 100 Mbps, but given the right conditions, it is estimated that the 802.11n speeds might be able to reach 600 Mbps. In practical operation, 802.11n speeds will be much slower.

802.11ac : The emerging Wi-Fi signaling standard, 802.11ac utilizes 5GHz channel. 802.11ac offers backward compatibility to 802.11b/g/n and bandwidth rated up to 6.9 Gbps at 5 GHz band. The speed is theoretical maximum and actual speeds will depend on several factors, like number of antennas, channel bandwidth, etc. For 160MHz channel, the speed is 867 Mbit/s, and 802.11ac can have up to 8 antennas at 160MHz channel, delivering 6.9Gbits/sec speed, theoretically.





Previous   Contents   Next