CWNA: Certified Wireless Network Administrator v108 — Question 13

You have implemented an 802.11ax WLAN for a customer. All APs are four stream HE APs. The customer states that it is essential that most of the clients can use the OFDMA modulation scheme. What do you tell the customer?

Answer options

• A. The clients that must support OFDMA must also be upgraded to 802.11ax
• B. OFDMA is an optional feature of 802.11ax and most APs don’t even support it
• C. All 5 GHz PHYs use OFDM modulation, so you will achieve OFDMA everywhere in 5 GHz
• D. If the devices support 802.11ac, they can be updated to support OFDMA through driver upgrades

Correct answer: C

Explanation

The correct answer is C because all 5 GHz PHYs operate using OFDM modulation, which allows for the implementation of OFDMA in that frequency band. Option A is incorrect because while 802.11ax clients are optimal for OFDMA, it is not a strict requirement for all clients. Option B is misleading as OFDMA is part of the 802.11ax standard, and many APs do support it. Option D is also incorrect since 802.11ac devices cannot be retrofitted to support OFDMA merely through driver updates.