Today I will write to you about seven wonderful techniques used in the latest generation WiFi6 devices by 802.11ax standard, i.e. WiFi6.
Let’s start with the naming changes. The makers of the IEEE standards definitely envied cellular networks and changed the name from a technical name like 802.11ax to the straightforward named WiFi6. In this way, the issues of promoting new versions were simplified, referring to the versions of 4G and 5G cellular networks.
- 802.11b is WiFi 1
- 802.11a is WiFi 2
- 802.11g is WiFi 3
- 802.11n is WiFi 4
- 802.11ac is WiFi 5 and finally
- 802.11ax is WiFi 6.
So much for the names. Simple and direct, this change suits me very well.
What is most interesting, however, are the changes in the new version of WiF6, i.e. techniques that solve problems from previous versions of the standard.
Firstly, the speed has been significantly increased, allowing to reach 4Gbit/s on one band, and even 11Gbit/s with the aggregation of 3 bands, which is a shockingly large value.
Second, many aspects related to the quality of internet connections have been improved.
The range has also been improved, which in my opinion is one of the most important changes, and it should please most WiFi users in blocks with full concrete walls.
The capacity of the radio network was also improved, which resulted in the universality of this solution compared to the current concept of point-to-network communication. By universality, I mean the possibility of using a network-based on WiFi6 as a closed network for modern VR (Virtual Reality) services or gaming scream in one building.
Maybe some of you still remember the times when there were no extensive internet networks and we played PCs connected by cable in one room or on the floor of the dormitory. Thanks to this WiFi6 technology, these times may become real again, the only question is whether it concerns young people or rather people from the previous Internet era.
I will now tell you one by one what these new techniques will give us users in practice, and how this was achieved.
Let’s start with what excites everyone the most – the speed of the Internet.
Speed, thanks to which in practice much faster speeds were achieved in WiFi6?
The first shift
Increasing the speed of the Internet is the use of coding modulation in the 1024-QAM version, compared to 256-QAM in the WiFi5 version. What does this mean in practice?
In practice, the higher the modulation, the more bits per second are transferred in the radio channel, i.e. we have a higher speed or capacity if these bits concern several clients simultaneously. 256-QAM modulation allows to transfer 8 bits per symbol and 1024-QAM modulation 10 bits per symbol, so we have a gain of 25%. You might ask yourself why 2018-QAM encoding was not used right away, but the answer is not that simple.
As it happens in life, nothing is for free. The higher the coding scheme, the lower the sensitivity of the radio channel. Between 512-QAM and 1024-QAM modulation, the sensitivity drops by -3dB, that is almost twice. The gain is an extra 1Bit per symbol on but reduced range almost twice. This would mean that WiFi devices would have to have 16 antennas already and use other radio techniques to compensate for signal drop and maintain coverage.
If you look at the latest WiFi6 devices, you will find, among others, spider-shaped models with 8 legs turned to the back. It looks funny, scary, strange, unusual. And I will only tell you a secret that this is a very primitive, but effective way to implement an antenna system. Not every company can construct an advanced STA radio antenna system to maintain the aesthetics of the device. More on that later. Second change
Affecting the speed of the WiFi6 network, it is possible to use radio bands with a width of up to 160MHz, and in addition on several bands in parallel. The previous generation, WiFi5 provided devices that allowed the use of the 80MHz band, i.e. we have twice as much. An impressive change, although remember that WiFi devices still apply the same power limit, i.e. 0.1W. Here, by the way, we discover another secret of the technological rush associated with WiFi. The same radiation power from the antenna, so manufacturers have to look for very advanced radio techniques.
This is a MU-MIMO technique that originally increases the network capacity, but can also affect speed. I will tell about it in the next section.
WiFi network capacity 6
The new version of the WiFi6 standard introduces two major changes, positively influencing the increase in its capacity.
The first is the MU-MIMO (Multi-User, Multi-Input, Multi-Output) technique, i.e. a new way to communicate with multiple devices in parallel, through 8 parallel connections towards the user and 8 connections from the user to the WiFi router. The MIMO technique was already used in the previous version of WiFi5, but only towards the user and only on 4 parallel connections. So we have twice as many signals down parallel and multiplex up.
What has been achieved thanks to this? Firstly, increasing the capacity, because you can send 8 times more information to many receivers in parallel, secondly, speed, if all these connections are used at the same time by a limited number of users, and thirdly, the quality of the connection, which I will talk about later.
The second technique is OFDMA (Orthogonal Frequency Division Multiple Access) which is a new version of digital access to the band. It sounds very complicated and is, in fact, a very advanced digital radio encoding technique. In practice, it means that in one second you can deliver data to several users at the same time, and not only one receiver, as it was in the previous OFDM version in WiFi5, and the other 3 receivers had to wait for their data in the queue. So we have another technique that increases the speed, because the radio band is used much more effectively, and it is as much as 11%.
These are not all new products, as I mentioned, it is the turn of quality and capacity.
The quality of connections and the capacity of the WiFi6 network, what influenced them?
MU-MIMO for the second time
MU-MIMO, which I mentioned for speed, also affects the quality of the connection. The multipath transmission increases the probability of the signal reaching the receiver from different sides, and the receiver equipped with 8 antennas can additionally digitally reconstruct a part of the weaker radio signal and thus improve the quality. There is simply a greater chance that some of the 8 signals along the way will not be absorbed by the concrete wall, but will arrive directly or as electromagnetic reflections through windows, doors, plaster walls, etc.
There have also been changes that will save the battery of portable devices such as smartphones and laptops. TWT (or Target Wake Time) is a new technique that will allow the phone to save battery use by turning off the antenna signal when our device does not need to communicate. We will achieve this state when, for example, we read an article on the Internet, it will not help, however, when watching a movie, when you need to receive a data stream all the time.
These types of techniques have been working in the world of mobile phones for years, so it is good that the creators of the WiFi standard have decided to make such a positive change. This shows that the new standards take into account the convenience of the customer (charging terminals with electricity), but they are also starting to take care of the environment. Less energy is consumed compared to previous WiFi versions is a positive change. I like it.
One of the biggest shortcomings of the currently used WiFi standards is interference, i.e. interference between different devices from nearby transmitters. When one WiFi device works on, for example, channel 11, the other devices have no idea about it and can also use channel 11. Such radio signals are jammed, deteriorating or preventing the connection to WiFi. Manufacturers began to use algorithms that detected such collisions and changed radio channels.
In the new generation, a special protocol has therefore been created that will allow WiFi6 devices to prevent the use of shared channels. BSS Color (or Base Service Station Color) is a new technique that allows each WiFi6 router to broadcast its own colour encoded on 6 bits. Thanks to this, other WiFi6 routers, including the standard, will be able to transmit radio signals in their colour and avoid interference, i.e. interference between devices. We will feel the beneficial effects of this technique when similar devices are also used by our neighbours.
A significant change also appears in the area of WiFi6 security because a new access standard, i.e. WPA3, has been introduced. This security protocol makes it much harder for hackers to guess the password to access your WiFi network. Besides, even if they manage to discover some parameters, they will be useless because the standard assumes changing many parameters so that there are as few repetitive elements as possible.
The big change is that WiFi standardization bodies will require WiFi6 devices to always enforce the WPA3 standard as the primary, increasing user security to good morning.
This is a very practical change, because, as most of us know, WiFi network owners rarely change the access password and set very short and simple passwords. This change is necessary for our security, but especially for IoT devices, which, once turned on and configured, may not be supported for years.
Can you believe that the new WiFi standard also improves coverage? It will be possible thanks to the techniques already described.
WiFi6 range, has it really improved?
The provisions on unregulated, i.e. free for the sender and recipient, 2.4Ghz and 5Ghz bands assume that such devices can operate with a power limited to 0.1W, i.e. 100mW. For years, the creators of radio techniques have tried to increase the range of operation with limited radio power, and these parameters are interrelated. The more power an antenna can emit, the greater the range.
The WiFi6 techniques that I discussed previously, and in fact their superposition, also improve the coverage, and these are the MU-MIMO 1024-QAM encoding and the use of a wider 160MHz band.
Tests carried out by PC-LAB showed that two WiFi6 devices, gradually moving away from each other to other rooms (the distance and the number of walls between routers changed) with increasing distances, were able to communicate with each other at the beginning using WiF1 to WiFi6 standards that are, all generations. However, when the distance and the number of walls increased, they could only communicate using the WiFI5 and WiFi6 standards, i.e. the latest versions. WiFi6, however, gave quite a lot of the communication speed.
Versatility, i.e. changing the philosophy of WiFi6 network planning.
Where did the idea for a new generation of WiFi come from, if WiFi5 gave a really impressive performance, speeds often exceeding the speeds of home transmission providers?
Well, it turned out in practice that the number of devices that require WiFi transmission in our homes is starting to increase. Mobile phones, TVs, laptops, computers, and also refrigerators, thermostats on radiators, cameras, motion sensors, switches for remote management of smart home etc. When I recently looked at my home WiFi router, I was surprised to find that the number of WiFi connections is several times greater on the number of household members, so the argument is specific.
For example, imagine using VR glasses (Virtual Reality) to play in one room between several players. Fast transmission to the computer from individual players allows you to improve the reaction to the movements of opponents. And imagine this is not a theoretical invention. Manufacturers of WiFi devices, Asus and TP-LINK have announced for 2019 the release of WiFi6 routers dedicated to games in one room. They are a giant for players that, in addition to a powerful processor onboard, have 8 antennas (this is a practical application of the MU-MIMO technique, 4 × 4 in the case of these models) and thanks to the use of three 160 MHz bands (one 2.4 GHz and two 5 GHz ) 11 Gbit / s local speed is reached. So we go back to the times of battles in dormitories.
In addition to connecting to the network, these routers use a new generation transmission interface, the so-called “Link aggregation 802.3ad”, which means 2.5 Gbit/s on one port. In order to communicate these 11Gbit/s with the world, you need to connect the device to the router, which has 1 2.5Gbit/s port and 8 ports of 1 Gbit/s. It is already a network, not just a simple WiFi router. I do not suggest doing such an installation for your home.
One more comment on the design of antenna systems. By using advanced antenna systems, as Huawei did in the APN7060DN model, by installing antennas from devices designed for 5G cellular networks, you can maintain the aesthetics of the device, because all antennas are hidden in the box. In addition, as Huawei claims, the delay was reduced from 30ms to about 10ms, I would be happy to test it.
WiF6 and 5G, or how 3GPP mobile communication standards intend to hug the unregulated WiFi band
Taking a closer look at the new WiFi6 techniques, I found that they are very similar to the latest generation 5G cellular standard.
We find here: MIMO in WiFi called Multi-User Mimo, and in 5G MASSIVE MIMO. Connecting multiple bands at the same time is an idea straight from LTE, the so-called Carrier Aggregation, in the 4G LTE PRO standard extended additionally to the Dual Carrier standard, which allows devices to aggregate together (i.e. send data simultaneously) from LTE and WiFi bands. Using multiple 4G, 5G and WiFi bands simultaneously will allow operators to expand network capacity and additionally give customers the most Internet speed. Therefore, we again have an impact on the universality of the solution.
Other techniques used by both standards are: 1024-QAM modulation in WiFi6 and in 4G, 5G the 256-QAM scheme is used, WiFi uses the OFDMA access method, and 4G, 5G OFDM.
The last element that combines these two standards is the so-called beamforming, a technique that allows you to form a radio beam in the direction of the subscriber, without the need to send a signal around the antenna. As a result, interference is limited, and the power needed by the mobile device to communicate with the transmitter is limited, and it also reduces battery power consumption.
Licensed and unlicensed bandwidth
There is, of course, a difference between Wifi and cellular networks, i.e. the power of the radio transmitter mentioned earlier. The 4G and 5G bands are licensed bands and allow the system to be used with a much greater power, even above 100W, and are reserved only for the entity that pays for them. Such a bandwidth gives us much better conditions to maintain quality and capacity. WiFi, however, is limited to 0.1W and in addition, it is an unlicensed band, so it can be used by all devices: WiFi, radio mice, drones, IoT devices, etc.
The connection of 4G, 5G and WiFi makes sense only in a very small range, several meters in the room. However, if we combine WiFi with a small 4G, 5G transmitter and install multiple devices on floors throughout the building, we can build an amazing, universal network with great speed, capacity and quality. I will talk about this concept in the next podcast.
Is this coincidence a coincidence? Probably not.
The chairpersons of the five WiFi standardization groups are engineers from telecommunications companies promoting 5G networks. Besides, as I mentioned, thanks to such standardization, it will be possible to use radio communication systems even better for the benefit of customers. More speed, more capacity, convenient to use standard terminals everywhere.
Finally, I will say a few words about specific devices.
Which mobile devices already allow the use of the WiFi6 network.
When it comes to WiFi6 routers, there are already a lot of them because almost all manufacturers of WiFi chipsets provide or will deliver them at the beginning of 2020 at the latest. If you have a device from a company today and you like it, I am convinced that within six months you will be able to buy a newer version in the WiFi6 standard.
Do I recommend such a change? Only in a sensible way. I would treat it as an evolution, so the exchange should take place when any of the described parameters are limping and you are looking for a solution to it, the most practically I would see the issue of range. As for today, I don’t need this change, do you?
As for the devices themselves, you can already buy devices for home, office or dedicated to players, such as the mentioned Asus ROG Rapture GT-AX11000 or TP-LINK Archer C5400X models.
If we look at the end devices that we carry in our pockets every day, it looks miserable today.
Only Samsung with models: Galaxy Note10, Galaxy Note10 + and Galaxy S10 (the latter without official certification) are compatible with WiFi6. The latest iPhone 11 also uses WiFi6 with MIMO 2 × 2, and this is probably just the beginning.
Phew, a lot of this technology news. The only question is whether it is technical or practical? After reading it, you will be able to judge it yourself. Nevertheless, it is a huge technical advance.
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