Meet the 6th Generation of Wi-Fi

It's forecasted that in 2022 about 5.7 billion people will be mobile users and mobile devices in business will reach 12.3 billion. And we constantly ask for more from our internet like streaming 4k movies, VR/AR and video games, it only makes sense that our Wi-Fi should get better.

Then from IoT side, it's estimated that the number of connected IoT devices per second will reach 152k by 2025, which means more and more devices are getting connected. Before, it might be sensors, but in the near future, everything is going to be connected, such as lighting, badge, vending machine, MRI, X-rays and so on.

Before we have cellular and Wi-Fi, and these two are like two islands, but in the near future Wi-Fi 6 is going to be working together with 5G.

To put it simply, we are more dependent on the network than ever before. That's why Wi-Fi 6 comes into play.

1. What is Wi-Fi 6 (802.11ax)?

As we all know, our Wi-Fi was named 802.11a / b / n / g / ac / ax by IEEE standard. This naming method is really confusing, and it is not easy to see the sequence. So on October 4, 2018, the WiFi Alliance renamed 802.11ax to Wi-Fi 6. And the previous generations of Wi-Fi names were changed accordingly to Wi-Fi 1-5.

2. 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.

• High-level MU-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. 

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?

3. Wi-Fi 6 deployment scenarios

• Public Venues

There is the high population density in public venus, such as airport, stadium, convention centers, railway and metro stations. With features such as OFDMA, MU-MIMO, Wi-Fi 6 can offer a more consistent and dependable network connection in a hyper-dense environment. For example, in a ball game, you can upload the video of the game on social media, share what you are excited about in real-time.

• Industrial IoT

For battery life is very crucial for IoT, but with the wifi 6, IoT application can go mainstream as well. With TWT, IoT devices can send traffic while retaining battery level.

Wi-Fi 6 can enable live video monitoring, real-time energy monitoring, low latency communications with sensors, and augmented reality in the industrial field.

• Education

We are seeing students bring more Wi-Fi devices in a classroom, most students who attend to a lecture have a laptop, tablet and mobile phone at the same time, it requires high Wi-Fi capacity as well.

With Wi-Fi 6, every student can get access to the network in high-density areas, such as a lecture hall, a stadium. Wi-Fi 6 can also enable HD video teaching, distancing teaching and AR/VR mixed reality education experience.

• Healthcare

Wi-Fi 6 enables medical devices to stay connected consistently and to run longer on battery operation, improving patient care. It also allows medical staff to transmit high-density medical records faster.

Moreover, it opens up more applications in a hospital such google glasses, robotics and AR/VR solutions for remote video surgery.

4. Wi-Fi 6 and 5G

Both Wi-Fi 6 and 5G have similar technology building blocks, so they will have similar benefits. Wi-Fi 6 will be the dominant access technology when you are the home or in the office, while cellular will be the dominant technology when you are outdoors.

But there are still some challenges for the adoption of Wi-Fi 6 and 5G:

• Wi-Fi only devices cannot connect to the 5G core

People have to change their endpoint device to adopt Wi-Fi 6. For example,iPhone 11 supports Wi-Fi 6, but it doesn't support 5G, so when 5G becomes a norm and works with wifi 6, iPhone 11 users have to change their phone to achieve the benefit of Wi-Fi 6 + 5G solution.

• Lack of interface to enable a certain level of network manageability and policy control between 5G core and Wi-Fi
• No mechanism for a client to route traffic over one or more access types in an intelligent way

To Make sure Wi-Fi 6 and 5G communicate with each other, we need a unified policy and visibility, to ensure they can work and interpret better, achieving seamless mobility.

References:

5 Things to Know About Wi-Fi 6 and 5G: https://www.cisco.com/c/m/en_us/solutions/enterprise-networks/802-11ax-solution/nb-06-5-things-WiFi6-5G-infograph-cte-en.html

Cisco Visual Networking Index: Forecast and Trends, 2017–2022: https://davidellis.ca/wp-content/uploads/2019/05/cisco-vni-feb2019.pdf