Wi-Fi standards 802.11a to 802.11be for Network+

Try 3 questions on this

Pick an answer to see why each option is right or wrong.

1. A stadium's wireless network delivers high peak data rates but throughput per client collapses when thousands of devices associate. Which of the following 802.11 amendments was chartered to improve area throughput in such dense deployments?

   Right. In the game that’s Renown for your Networking Concepts building.

   Not that one: B is right. In the game your Networking Concepts building would lose a little Renown, and this question would come back later.

   Your answerA.802.11ac802.11ac is the Very High Throughput amendment for 5 GHz. It raised the peak rate a single client could reach, but its charter did not target area throughput under heavy user load, which is the stadium's problem.The answerB.802.11axThe IEEE 802.11 TGax page records that the High Efficiency WLAN study group was formed to consider 'the improvement of spectrum efficiency to enhance the system throughput/area in high density scenarios of APs and/or STAs', with a focus on 'dense heterogeneous networks in moderate to heavy user loaded APs'.Your answerC.802.11be802.11be was chartered in 2019 for Extremely High Throughput, with a maximum of at least 30 Gbps and lower worst-case latency. Those are speed and latency goals; the density charter belongs to the amendment before it.Your answerD.802.11n802.11n is the 2009 High Throughput amendment, the first to use multiple antennas for higher rates. It was not chartered around dense deployments and is the oldest option here.

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   That charter became project 802.11ax, so it is the amendment whose stated goal is real-world throughput when many clients share the air.

   Written from www.ieee802.org/11/Reports/tgax_update.htm

2. An office's new access points add the 6 GHz band to a network that previously used only 2.4 and 5 GHz. Which of the following Wi-Fi generations introduced operation in that band?

   Right. In the game that’s Renown for your Networking Concepts building.

   Not that one: C is right. In the game your Networking Concepts building would lose a little Renown, and this question would come back later.

   Your answerA.Wi-Fi 4Wi-Fi 4 is the Wi-Fi Alliance's name for 802.11n, which operates in the 2.4 GHz and 5 GHz bands. It predates 6 GHz operation by more than a decade.Your answerB.Wi-Fi 5Wi-Fi 5 is 802.11ac, specified below 6 GHz and in practice a 5 GHz generation. It has no 6 GHz operation.The answerC.Wi-Fi 6The Wi-Fi Alliance's generations page states that Wi-Fi 6 'also introduced Wi-Fi in the 6 GHz band in addition to the 2.4 GHz and 5 GHz bands available in previous generations'.Your answerD.Wi-Fi 7Wi-Fi 7 does enhance performance across 2.4, 5 and 6 GHz, and adds 320 MHz channels in 6 GHz. But the Wi-Fi Alliance credits the generation before it with introducing the band; Wi-Fi 7 widened the channels in a band that was already open.

   Show the full explanation and doc quotes

   Wi-Fi 7 operates there too, but as the inheritor of the band, not the generation that introduced it.

   Written from www.wi-fi.org/wi-fi-macphy

3. A small office upgraded its access point in 2003 to gain higher data rates while keeping existing 802.11b clients connected in the same band. Which of the following 802.11 standards did it adopt?

   Right. In the game that’s Renown for your Networking Concepts building.

   Not that one: B is right. In the game your Networking Concepts building would lose a little Renown, and this question would come back later.

   Your answerA.802.11a802.11a is the 'Higher Speed PHY Extension in the 5GHz Band'. Moving the access point to 5 GHz would have cut off every 802.11b client, which only works at 2.4 GHz.The answerB.802.11g802.11g-2003 is titled 'Further Higher Data Rate Extension in the 2.4 GHz Band'. It raised data rates while staying in the band 802.11b uses, which is why an 802.11g access point could keep serving 802.11b clients.Your answerC.802.11n802.11n, 'High Throughput', does cover 2.4 GHz and would keep 802.11b clients on the network, but the IEEE timeline dates it to 2009. In 2003 it did not exist.Your answerD.802.11ac802.11ac, 'Very High Throughput below 6 GHz', dates from 2013 and runs in the 5 GHz band. It is both too late and the wrong band for 802.11b clients.

   Written from www.ieee802.org/11/Reports/802.11_Timelines.htm