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Q&A
© 2019 Cisco and/or its affiliates. All rights reserv ed. This document is Cisco Public. Page 1 of 2
TechWiseTV Workshop: Cisco Catalyst 9100 Access
Points for Wi-Fi 6
July 31, 2019
Q. Full 802.11ax support of the 6-GHz band may not happen before the end of 2020, so the Wi-Fi 6 timeline
should be stretched beyond 2020.
A. While 6-GHz support is part of IEEE draft 4.0+, it is not a mandatory feature for release 1 of 802.11ax (know n as
Wi-Fi 6). As w ith 802.11ac, w e potentially may see release 2. There’s no question that Wi-Fi 6 w illextend w ell
beyond 2020, for reasons that go beyond the new bands. I agree w ith you!
Q. Will we be able to leverage common authentication flows between 5Gand Wi-Fi 6? So we can move
from one network type to another?
A. Today, management is done as separate domains, including authentication, roaming improvements, carrier
offload, and QoS management. This encompasses an architecture w ith common APIs betw een the control points
of these netw orks.
Q. What percentage of Wi-Fi 6 capable endpoints do I need to reach in a campus (let’s say 1000 people
total) to capitalize on WiFi-6 efficiency gains?
A. You can start to see improvements as soon as you have multiple Wi-Fi 6 clients. The AP w ill try to group those
Wi-Fi 6 clients together and share the frame among them. It w ill depend on the traffic needs of those clients.
Q. I interpret your answer to mean that it’s decided in the standard.
A. I’m not sure about the premise of your question, but it could be my lack of know ledge. I am not aw are that a
minimum of 106 resource units (RUs) are needed. I believe that orthogonal frequency-division multiple access
(OFDMA) enables the use of RUs w ithout a minimum requirement—yes, based on the latest draft. This, I believe,
is based on performance simulations. [[Is “resource units” correct?]]
Q. Well, if Jim Florwick says you need 106 RUs to do MU-MIMO, I assume that’s how it’s supposed to work.
I was just curious as to why.
A. I respect that source! I w ill ask him; thank you for raising the question. Also, this note is referring to minimum
bandw idth (20 MHz), as reception of RU in high-efficiency multiuser physical protocol data units (HE MU PPDU),
w here RU spans the entire bandw idth, is allow ed as per the standard.
Q. My audio cut out again after Robb started speaking. Perhaps it's a local Bluetooth issue?
A. It might be. You'll receive a thank-you email w ith the recording in case you missed anything. Thank you for
joining today.
Q. Is the limitation that you need 106 RUs before you can do OFDMA and MU-MIMO a limitation in the
standard or in the chipsets?
A. It is related to performance improvements that can be delivered, factoring in the transmit quality (error vector
magnitude [EVM]) requirements.

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© 2019 Cisco and/or its affiliates. All rights reserv ed. This document is Cisco Public. Page 2 of 2
Q. Looking back at the OFDMA scale slide for Wi-Fi 6, is the advantage of Wi-Fi 6 only when all clients are
Wi-Fi 6 capable, or also with a mix of current devices?
A. Throughput benefits and pow er efficiency benefits are applicable to Wi-Fi 6 clients only. How ever, spectrum
capacity benefits can be seen in mixed-device environments w ith improvements in scheduling algorithms.
These benefits may not be as pronounced.
Q. Does the 9120 run a hypervisor? For app hosting?
A. It’s a Docker Style container
Q. I would be interested in seeing a slide showing how capacity increase as a percentage of clients on Wi-
Fi 6 grows over time.
A. That’s being looked at in our testing labs today, including mixed-mode environments.