Vijay Nagarajan

CTS 106: 802.11ax with Broadcom

Vijay Nagarajan of Broadcom joins CTS to discuss what’s new with 802.11ax and it’s future with Broadcom.

This episode is sponsored by Metageek

Sponsored by Metageek

Broadcom Delivers 802.11ax Solutions

On August 15, 2017 Broadcom announced their 802.11ax ecosystem of products labeled Max WiFi. In this episode, Vijay Nagarajan joins us on the show to discuss the future standard – 802.11ax. Vijay is head of marketing for all connectivity at Broadcom. He has also represented Broadcom at the Wi-Fi Alliance for 802.11ac.

802.11ax touts increased efficiency of Wi-Fi communications. Whereas previous standards had focused more on throughput, 802.11ax will get higher throughput by using the wireless medium more efficiently.

In our discussion with Vijay, he mentions how there is substantially more video consumption on wireless devices. And with 802.11ac we saw throughput increase and standardized beamforming. More use cases are being added on such as video uploads from places such as concerts and sporting events.

Upload traffic has risen because of social media and sync technologies. Everyone wants to stream the latest game or concert. And with the number of devices increasing per person we will see even more traffic.

The biggest news about 802.11ax is OFDMA or Orthogonal Frequency-Division Multiple Access. An analogy Vijay uses – picture a highway. You slice up that highway into multiple lanes. In RF, splice the frequency spectrum into bandwidths that are proportional for the devices. Devices are scheduled for when they can transmit or receive using target wake time (TWT). I thought of this as like giving devices tokens – access to transmit or receive.

OFDMA explainer

Broadom’s Max WiFi OFDMA. From http://maxwifi.org/how-max-works/

In OFDM, we had one device transmit or receive data while other devices waited for their chance to use the shared medium. And this caused draining batteries while waiting to access the medium.

Fran├žois posed the question, why haven’t we not used OFDMA before? Vijay’s opinion was because Wi-Fi was built initially with simplicity. There was availability of spectrum. Now we need efficiency.

What else is new with 802.11ax? Coloring with spacial channel reuse. There is a signature associated with each BSS. Coloring will help networks use available spectrum more efficiently.

And then theres MU-MIMO. 802.11ac introduced downlink MU-MIMO only. Now, 802.11ax introduces both uplink and downlink MU-MIMO. While I haven’t seen this used in the wild yet (MU-MIMO), I am still skeptical if this will be used in the future but only time and device drivers will tell.

In conclusion, Broadcom has taken strides to become bleeding edge. They’ve released 802.11ax chips and with CES 2018 we saw announcement of the first 802.11ax routers. Even Aerohive has made the announcement of their own 802.11ax access points. Downside, we don’t have any device clients, that I know of, in the wild. It will be interesting to see if the adoption of 802.11ax will be stronger than 802.11ac or just as strong as 802.11n was.

Links and Resources