Wi-Fi 6 Key Features

OFDMA

Imagine your Wi-Fi connection as a series of delivery trucks delivering data packets to your devices. With 802.11ac Wi-Fi, each delivery truck or packet could only deliver one parcel to one device at a time. No matter the user refreshes the web page, or downloads a huge file, or just does messaging, it would be the same overhead. It’s like you just order a small coke from MacDonald's from Uber Eats, the delivery man has to deliver it just for you. So there is a lot of overhead wasted and a lot of time waiting. 

But in Wi-Fi 6 there is a new technology called OFDMA, which is orthogonal frequency-division multiple access. Each truck can deliver multiple parcels to multiple devices simultaneously. All users get resource at the same time and they can respond back at the same time. 

This OFDMA feature significantly increases efficiency and reduces latency. 

BSS COLORING:

When too many access points (APs) and clients hear each other on the same channel, it is called an overlapping basic service set (OBSS). For example, the tablet is trying to connect to the AP, and it founds 3 APs on the same channel, now the tablet is confused. This is signal interference.

The solution is BSS coloring, which is a method for identifying OBSS.

Now if different APs that operate on the same channel, each of them will have a color and tells the tablet, so the tablet knows which AP to connect and ignore the interface from the other APs. Now each client gets the best quality connection possible.

If you've ever lived in an apartment or close to your neighbors, this BSS coloring feature minimizes Wi-Fi conflicts with your neighbor and allows for interference mitigation.

MIMO

Wi-Fi 5 introduced 4x4 MU-MIMO (multi-user, multiple input, multiple output), meaning an AP could communicate with up to four clients at a time, but it works only in the downlink (AP-to-client) communications. Uplink MIMO (client-to-AP) is still single-user in Wi-Fi 5. 

MU-MIMO 

But in Wi-Fi 6, it is using 8x8 MU MIMO both downlink and uplink, which means one AP can address eight client devices bi-directionally. 

This enhanced MU-MIMO increases capacity up to 4 times, means that whether you're streaming, downloading, playing VR/AR, with Wi-Fi 6's 8 streams, there's enough bandwidth for more devices.

Target Wake Time (TWT)

Without Target Wake Time (TWT), since the AP can only communicate with one station at a time, the stations (which are mobile devices) have to “stay awake” to receive data packets from the AP one after another regardless of how long that process takes. When station 1 is exchanging data with AP, station 2 is in an idle state and waits until the AP finishes its communication with station 1. This causes extra power consumption and shorter battery lives for network devices.

Target Wake Time (TWT) is a new feature that allows an AP and stations to “wake up” at negotiated times. The stations and AP reach a TWT agreement that defines when a station is awake to receive and send data. Stations only wake up at TWT sessions and remain in sleep mode for the rest of the time.

It's like you are home waiting for a friend, and before, you have do go downstairs every 5 mins to check if you friend arrives, but now, you just stay at home waiting for you friend rings the bell, that's it. And also, since you have made an agreement with your neighbors, so when you go out, all resource is just for you, the elevator is just for you, the taxi is waiting for you in front of your apartment, you are the only customer in a restaurant. This is super-efficient, isn't it?