▷ 802.11Ax vs 802.11ac, features and performance

The 802.11ax wireless communication protocol is a reality and Asus has been the first to provide us with a team that implements this solution for home use. The Asus RT-AX88U will be the first of many others, but for now, this router is the one that holds the primacy of the new protocol aimed at overcoming wired connections in a short space of time.

In this article we are going to make a comparison of the old protocol IEEE 802.11ac vs 802.11ax, to see the fundamental differences between one and the other and again if the changes have really been substantial or it is a facade.

Index of contents

802.11ac vs 802.11ax

To put ourselves in a situation, we are going to know a little about the previous 802.11ac standard. This standard is the evolution of the previous 802.11n protocol, also known as WiFi 5, mainly because it implemented wireless connections in a 5 GHz frequency band. It was developed between 2011 and 2013, and represented a substantial improvement over the previous protocol, thanks to the use of this new frequency band to provide much larger data transfers with MIMO capacity.

For its part, the new standard 802.11ax or also called Wi-Fi 6, is intended to improve the performance of wireless connections, especially in public environments and spaces where the connection of a large number of devices makes the Wi-Fi network Fi quickly saturates with the previous protocol. One of the new features it brings is the evolution of MU-MIMO to OFDMA technology that improves performance in large workloads.

Why do we need a new Wi-Fi protocol

The number of devices using wireless networks has increased dramatically in recent years. The current mobile phones are far from the performance of the models that were back in 2011. For this reason, the 802.11ac protocol has fallen short in terms of possibilities and benefits.

This is especially marked in places of public attendance, such as airports, universities, stations, hotels, etc. Places that have free Wi-Fi access points quickly become saturated with the large number of users who intend to take advantage of this service, and the MU-MIMO technology implemented by devices under this protocol is insufficient. What this technology basically does is optimize the wireless signal to allow simultaneous transmissions to the clients that are connected to the access point. However, MU-MIMO has already become too small.

This is why the 802.11ax protocol is specially designed to overcome the limitations found. With the new OFDMA technology, in addition to delivering or receiving data from multiple antennas, it will be able to do so for several users at the same time. The process of grouping signals by means of RUs or units of resources, will allow us to better manage bandwidth for large data loads. This removes the limitation of the old CSMA / CA Ethernet technology where clients need to listen to the signal before they can transmit.

Another objective of this new version of IEEE is to improve the efficiency in terms of energy consumption of antennas and the network, something critical for portable terminals and that should always be taken into account.

802.11ax vs. 802.11ac speed

Without a doubt one of the main reasons for the existence of this new protocol is to increase the speed of data transfer in wireless connections. Not only in the 5 GHz band, but also in the 2.4 GHz band, since it works in both.

The 802.11ac protocol had, so to speak, its ceiling, with the extraordinary Asus ROG Rapture GT-AC5300 router. This beast is capable of reaching AC5300 speeds thanks to its 8 WiFi antennas at speeds in the 2.4 GHz band in 4 × 4 mode up to 1000 Mbps and in the 5 GHz band in 4 × 4 mode up to 2167 Mbps. By having 8 antennas, we could effectively reach 5200Mbps in dual 4 × 4 mode. Figures that until a few months ago seemed brutal to us on Wi-Fi. In addition, this router is one of the few that uses 1024-QAM under this protocol.

But now our friend Asus RT-AX88U enters, a router that mounts 4 Wi-Fi antennas to provide us, under 802.11ax, 4 × 4 connections in the 2.4 GHz band, reaching speeds of up to 1148 Mbps, and connections 4 × 4 in the 5 GHz band a record of no less than 4804 Mbps. Without a doubt a substantial improvement, especially in the higher frequency band, which will allow us much higher transfer speeds.

But this is not all, the most interesting thing about the devices that mount this protocol is that they can make connections of up to 8 × 8, that is, 8 antennas in parallel to provide us with incredible speeds. There are still no models that implement this possibility, although we already have the Asus ROG Rapture GT-AX11000 gaming router on the market with the capacity for a double 4 × 4 connection in the 5GHz band, which doubles, so to speak, the capacity of the RT -AX88U. It is capable of up to 11000 Mbps, figures that will undoubtedly exceed 10 Gbps wired connections. For now the theoretical maximum recorded is around 14 Gbps.

We already know that there are still no AX clients on the market to squeeze these new routers, which is a major disadvantage. In the tests carried out with the AX88U, we connect up to 6 equipment 3 to 3 trying to measure the speed of the trunk link between two AX routers. Although the results far exceed the AC protocol, we never managed to reach the maximum possible.

What we could see first-hand was OFDMA's capacity with 6 computers connected and each operating at more than 700 Mbps, something that is undoubtedly one of the great best regarding 802.11ac. We see that we were able to reach speeds close to 2.5 Gbps, which should be struck when there is a 4x4 ax client.

Use of frequency bands

Directly from the previous point we can draw another of the most significant differences between both protocols, is the frequency band in which they work.

802.11ac is capable of operating only in the 5 GHz band, expanding the bandwidth to 160 MHz, compared to 40 MHz in which 802.11n works. It is also capable of working on eight channels or MIMO flows.

In contrast , the 802.11ax protocol, in addition to working in this same 5 GHz band, also works in the 2.4 GHz band, a very important novelty to optimize the transfer of information in this versatile frequency band. In this way, more available channels are created, specifically we will have up to 8 channels for the 5 GHz range (8 × 8) and 4 for the 2.4 GHz range (4 × 4). This of course improves the capacity and bandwidth to transmit using MU-MIMO in duplex mode, in which a single access point will be able to transmit to several receivers simultaneously.

802.11ax performance and backward compatibility

As for the operating characteristics of the new protocol, it is one of the most differentiating issues regarding the AC version. The new protocol can offer us up to 40% more performance than the old version, thanks mainly to the new QAM modulation. The objective of QAM is to transport two signals modulated both in phase and in amplitude independently by the same channel. The spacing between carrier signals for this new protocol has been drastically reduced to spaces of only 312.5 KHz to provide them with a greater frequency spectrum.

While 802.11ac works normally at 256-QAM, 802.11ax does it no less than 1024-QAM. By increasing this record, we are increasing the density of information that the device is capable of transmitting. This is why the data transfer rate for a single antenna with AX will be 37% higher than that which is capable of transmitting the AC protocol. With this record we have that a single antenna of the Asus RT-AX88U will be able to transmit a little more than 1000 Mbps, there is nothing.

Next, we will see a table that shows some of the results and differences between both protocols.

We see that 802.11ax works on both bands while 802.11ac does not. The bandwidth used is the same for both protocols to obtain maximum compatibility between different standards. For its part, the spacing between signals is shortened enough in the new protocol to make way for greater bandwidth thanks to OFDMA. Latency in this regard also improves considerably.

Using OFDMA technology, the ability to send 4-simultaneous Multi-MIMO transmissions for the AC protocol has been doubled to 8, which the AX protocol can do. With beam focusing technology, the router will be able to target clients more precisely to optimize the transfer rate. The CPU that works in the router, divides each MU-MIMO flow into four additional ones to increase up to four times this Bandwidth per connected client, in this basically lies the novelty of OFDMA technology.

Another of the most interesting features, although it is not new, is that we will have perfect backward compatibility between this new protocol and the previous ones. A device that works under an 802.11n protocol for example, will be able to connect perfectly to one that works with the new 802.11ax, this will avoid having to acquire new hardware to implement networks in which there is a diversity of equipment.

Of course the 802.11ac protocol is also backward compatible with other IEEE, but this aspect has been considerably improved for the new creation, since, as we have seen before, the AC protocol does not work on the 2.4 GHz frequency, and the AX yes it does.

Equipment and hardware that will implement 802.11ax

We have already talked at length about the novelties that this new standard brings to wireless transmissions, so now it is time to see how this has started in the market for home routers.

Asus has been the first company to market a computer under this protocol. The Asus RT-AX88U installs two Broadcom BCM43684 microprocessors capable of supporting 4 × 4 MU-MIMO and OFDMA 1024-QAM modulated connections, in addition to other 64-bit Broadcom BCM4908 core processors. The channel bandwidth is 160 MHz and can reach a speed of 4.8 Gbps in the 5 GHz band and 1.1 Gbps in the 2.4 GHz band.

A few days ago we had access to another model with higher performance and successor to the Rapture GT-AC5300, the Asus ROG Rapture GT-AX11000, whose review you can see here. This router mounts three Broadcom BCM43684 processors to manage wireless networks and another Broadcom BCM4908. The router can reach no less than 11 Gbps on a double 4 × 4 connection in the 5 GHz band and another 4 × 4 in 2.4 GHz band.

802.11ax is here to stay, and proof of this are the incredible benefits that we are going to see from now on for the new routers that are creating the brands, with Asus as a trend to follow.

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With this we conclude our comparative study of 802.11ax vs 802.11ac, we hope that this article will be of your interest to see both protocols with a better perspective and that the future holds. What do you think of this new implementation? Write us about this in the comment box.