The number of devices and requirements for data transfer rates in wireless networks are growing every day. And the denser the networks, the more clearly the shortcomings of the old Wi-Fi specifications are visible: the speed and reliability of data transfer drops. To solve this problem, a new standard was developed - Wi-Fi 6 (802.11ax). It allows you to develop a wireless connection speed of up to 2.4 Gb / s and work simultaneously with a large number of connected devices. We have already implemented it in the router and adapter . In this article, we will show their capabilities.
New in WiFi 6
The previous standard - Wi-Fi 5 (802.11ac) - was developed 9 years ago, and many of its mechanisms are not designed for a large number of connections. As the number of devices increases, the speed of each of them decreases, since mutual interference occurs at the physical layer and too much time is spent waiting and coordinating the transmission.
All the innovations of Wi-Fi 6 are just aimed at improving the performance of a large number of devices in a limited area, increasing the transmission speed for each of them. This problem is solved simultaneously in several ways, which boil down to increasing the efficiency of using the frequency spectrum and reducing the mutual interference of neighboring devices. Here are some key ideas.
BSS Coloring: Helps reduce the impact of neighboring access points
When the areas of several access points overlap, they prevent each other from starting a transmission. This is due to the fact that in Wi-Fi networks, access to the medium is implemented in accordance with the CSMA / CA mechanism (Carrier Sense Multiple Access with Collision Avoidance): the device periodically βlistensβ to the frequency. If it is busy, the transmission is delayed, the frequency is listened to after a while. Thus, the more devices connected to the network, the more each of them has to wait for their turn to transmit the packet. If there is another wireless network nearby, listening to the frequency will indicate that the transmission medium is busy and transmission will not start.
Wi-Fi 6 has a way to separate "own" transmission from "foreign" - BSS Coloring. Each packet transmitted over a wireless network is marked with a certain color, the transmission of other people's packets is simply ignored. This greatly optimizes the process of struggle for the transmission medium.
1024-QAM modulation: transmits more in the same spectral bandwidth
Wi-Fi 6 implements a higher level quadrature modulation (compared to the previous standard): 1024-QAM, available in the new MCS 10 and 11 coding methods. It allows 10 bits of information to be transmitted in a packet instead of 8. At the physical layer, this increases speed transmission by 25%.
OFDMA: condenses the transmission by using every hertz and millisecond
OFDMA - Orthogonal Frequency Division Multiple Access - is an idea for the further development of OFDM, borrowed from 4G networks. The frequency band in which the transmission is carried out is divided into subcarriers. To transmit information, a number of subcarriers are combined, so that several data packets are transmitted in parallel (on different groups of subcarriers). In Wi-Fi 6, the number of subcarriers is increased by 4 times, which in itself allows you to flexibly handle the loading of the frequency spectrum. At the same time, the transmission medium, as before, is divided in time.
Long OFDM symbol: makes transmission more stable
The transmission efficiency determines not only the density of information βpackingβ, but also the reliability of its delivery. To improve reliability in a busy electromagnetic spectrum, both the symbol length and the guard interval have been increased in Wi-Fi 6.
2.4 GHz support: gives choice for different propagation conditions
Wi-Fi 5 devices supported the previous Wi-Fi 4 standard in this range, which did not meet the increased frequency spectrum requirements. Using the 2.4 GHz band gives you a longer range, but it has a slower data rate.
Beamforming and 8x8 MU-MIMO: keep the air warm
Beamforming technology allows you to dynamically change the beam pattern of the access point, correcting it towards the receiving device, even if it moves. MU-MIMO, in turn, allows you to send and receive data to multiple clients at once. Both technologies appeared in Wi-Fi 5, but at that time MU-MIMO was possible only for data transmission from the router to the consumer. In Wi-Fi 6, both directions of transmission have earned (although at the moment they are both controlled from the side of the router). At the same time, 8x8 MU-MIMO means that the channel will be available simultaneously for 8 download streams and 8 download streams.
Archer AX6000
Archer AX6000 is the first TP-Link router with Wi-Fi 6 support. It has a large body (25x25x6 cm) with folded antennas and a powerful 12V 4000 mA power supply:
The router has 8 gigabit LAN ports, a 2.5 Gb / s WAN port and two USB ports: USB-C and USB-3.0. Also on the end are the control buttons for WPS, Wi-Fi and light indication on the central icon:
The router is designed to be mounted on a table or on a wall using two self-tapping screws:
To remove the top cover and see what's inside, you need to remove the soft plugs from the back, unscrew the four screws, and then snap off the cover. Since there is an indication on the top cover, a cable is pulled to it, which must be disconnected:
Inside, everything is packaged in one board with several powerful heatsinks: the model works silently and is suitable for installation at home or near the workplace. Hidden under the heatsinks is a quad-core 1.8 GHz processor and two co-processors from Broadcom.
To get to the other side of the board, you need to disconnect the antennas that are attached to the UFL connector. The antennas themselves are held on by clips and can be easily removed:
As prescribed by the standard, the device supports 8x8 MU-MIMO. Together with OFDMA in busy networks, the technology allows you to increase throughput up to 4 times compared to Wi-Fi 5 devices.
You can experiment with functions in (by the way, it also has a switch to Russian). The router itself supports standard network settings: WAN, LAN, DHCP, parental control, IPv6, NAT, QOS, guest network mode.
Archer AX6000 can work as a router, distributing Internet to wired and wireless users, or as an access point:
At the same time, a wireless network can be deployed simultaneously in two frequency bands - if necessary and if there is appropriate support, clients are transferred to a less loaded one:
From the advanced settings, there is a choice between Open VPN and PPTP VPN:
Additional security is provided by the built-in antivirus, with which you can configure the filtering of unwanted content and protection against external attacks. Antivirus, like parental control, is based on TrendMicro products:
Connected USBs can be assigned as a shared folder or FTP server:
Of the advanced features for the home, the AX6000 has support for Alexa and IFTTT voice assistant, with which you can create simple home scenarios:
Archer TX3000E
The Archer TX3000E is a Wi-Fi and Bluetooth adapter that uses an Intel Wi-Fi 6 chipset. The kit includes the PCI-E board itself, a 98 cm remote magnetic base with two antennas, and an additional mount for system units of a smaller form factor. The antennas use a standard SMA connector, so if necessary, they can be replaced with longer ones.
When operating in 802.11ax compatible mode, this adapter provides a maximum speed of 2.4 Gbps. So, when the communication channel is limited to 1000/500 Mbps:
What about range?
The transmission range as a characteristic of a particular device can be considered in two situations: in the absence of other devices and obstacles, as well as in a dense network of some typical configuration.
In the first case, the transmission range is determined by the power of the transmitter, and it is limited by the standard. With the support of Beamforming data, the range will definitely be higher than the devices of the previous version of the standard, since the radiation pattern of the transmit antenna array will be corrected in the direction of the client device. It will only make sense to talk about some tests when a wide range of Wi-Fi 6-enabled devices enter the market, implementing beam correction in different ways. But even in this case, the test will be rather laboratory, having nothing to do with the actual operation of these devices.
In the second situation - when the router transmits data in the vicinity of other similar devices - comparison with previous standards is also meaningless. BSS Coloring will allow you to receive the signal much further, even if a router is working nearby on the same channel. MU-MIMO will also play a role here. In other words, the standard itself is built in such a way that comparison by this parameter is meaningless.
Source: habr.com