Imagine you are driving on a motorway where no overtaking is allowed. You can develop a decent speed, but in the end you meet a lorry driver in your lane who is more interested in the last season of the Game of Thrones than your horn. This is probably how the WiFi network you are currently using works. That is why the new IEEE 802.11ax standard, also known as WiFi 6, places the emphasis on the data transmission capacity. How does it work in practice? Fasten your seat belts – we explain!
It can be hard with road hogs. Especially when the master of the steering wheel has a lousy transfer. So let's start with the speed – what is 802.11ax hiding under the hood? As another model in the 802.11 series, WiFi 6 continues to use the 5 GHz band, which ensures full backward compatibility. This does not mean, however, that the ax cannot boast interesting speed test results.
Thanks to 1024-QAM encoding, which increases the amount of data per packet, the maximum transmission speed in the 160 MHz channel has increased to 3.5 Gb/s, while in ac networks the transfer rate is 866 Mb/s at most. In the case of 40 MHz channels in turn, which are used in public spaces, we can expect transmission of 800 Mbps per stream.
However, what makes WiFi 6 stand out the most from its predecessors is its much more efficient use of waves.
MIMO: it is still about capacity
Like its predecessor, the first step that 802.11ax makes towards improving radio bandwidth is to use MU-MIMO (multi-user multiple input/multiple output), both for uplink and downlink transmissions. This technology enables simultaneous transmission and reception of data by multiple recipients at the same time, in independent streams. MIMO 4×4 allows to achieve speeds close to 5 Gb/s.
However, the problem to be solved was inefficient use of the control layer of access to the transmission medium. When the number of users was growing or when small portions of data were being transmitted, MAC was "jamming", reducing network efficiency. WiFi 6 was therefore faced with a major challenge: how to increase its spectral efficiency? The Orthogonal Frequency-Division Multiple Access (OFDMA) modulation came in handy.
Joint the traffic!
By using OFDMA, 802.11ax optimises the network spectrum, not only adding more lanes to our web motorway, but also making it easier for you to get into traffic. In OFDMA, each band is divided into tens or hundreds of subchannels working within different frequencies, which are called time-frequency resource units, or RUs. For example, instead of 64 tones at 312.5 kHz, we will have 256 tones at 20 MHz.
RUs are divided and assigned by Access Point to specific terminals based on the TXOP media access method, which allows to send multiple frames and confirmations without the need for competition. This optimises the efficiency of uplink and downlink transmission, resulting in a more economical and "dense" use of the radio bandwidth while reducing the number of collisions. Do you see now where we are heading? :)
An optimal solution to the letter
802.11ax is not designed to increase the speed of transmission for individual devices, but to improve the overall performance of the network. The greatest advantage of WiFi 6 can therefore be seen in its increased bandwidth, which allows a significant number of devices in a small space to gain very fast Internet access without major obstacles.
It is particularly important at a time when the growing number of smartphones, laptops, network drives, smart speakers, multimedia devices and smart 4K TVs in our offices and universities "jams" the data transfer. The Internet of Things (IoT) has been growing constantly since its onset and is putting a significant strain on the entire infrastructure. This means the need for solutions tailored to present and future needs.
The AP505i and AP510ie Access Points from Extreme Networks, based on the 802.11ax standard, are capable of speeds up to 4.8 Gb/s. Supporting three or four data streams, client devices easily reach bandwidths above 1 Gb/s. A less congested road means not only a faster journey, but also more satisfied network users. No nerves, no delays, and no road hogs! :)