Hi all,
This post mainly talks about the key Technology of WiFi6.
The WIFI6 increases the system capacity through a series of system features and multiple mechanisms, improving the working mode of the Wi-Fi network through better consistent coverage and reducing air interface media congestion. Especially in a dense user environment, providing consistent and reliable data throughput for more users, the goal is to increase the average user throughput by at least four times. That is to say, the Wi-Fi network based on 802.11ax means unprecedented high capacity and high efficiency. WIFI6 has four main features: Large bandwidth, high concurrency, low latency, and low power consumption. Now, let's see how WIFI6 improves these performance indicators.
1. Large bandwidth
The peak rate of Wi-Fi is determined by three factors. The first is the bandwidth, that is, the width of the frequency band occupied by Wi-Fi. We know that the width of the frequency band is basically proportional to the actual throughput of the data. Under the WIFI6 standard, the width of the frequency band reaches 80MHz and 160MHz. The second key technology is MU-MIMO, and MU-MIMO actually improves data sending capability by using multiple groups of antennas. The wireless algorithm enables different antennas to transmit different data. In this way, the more antennas, the larger the amount of data to be sent at the same time. The gain and rate of the MU-MIMO are also in direct proportion. That is, the rate of the 4T4R is twice the rate of the 2T2R. WIFI6 supports uplink and downlink MU-MIMO transmission.
The third key technology is the air interface modulation technology. The WIFI6 uses the 1024QAM modulation technology. QAM refers to quadrature amplitude modulation, which is a modulation mode in which amplitude modulation is performed on two orthogonal carriers. The two carriers are usually sine waves with a phase difference of 90 degrees, and therefore are referred to as orthogonal carriers. QAM is used to modulate and demodulate data by using a constellation diagram (a dot matrix diagram). A simple understanding of a modulation technology is a bit of valid digital information that can be carried on each radio symbol. In actual application, the relationship is the N power of 2. For example, if the 11ac standard is 256QAM and the 256 is the eighth power of 2, eight bits of data can be transmitted at a time. Therefore, in a constellation set of the 256 lattice arrays, any point may carry data information of eight bits. After 802.11ax, a higher order code is introduced, that is, the tenth power of 2, and 1024-QAM. Each modulation symbol may carry 10 bits of data. Compared with 802.11ac, the peak rate of data transmission is increased by 25%. Therefore, WIFI6 uses 1024QAM and 8*8 MU-MIMO to achieve a peak rate of 9.6Gbit/s, which is four times higher than that of the previous generation.
2. High concurrency
Compared with 802.11ac, WIFI6 has four times higher throughput than 802.11ac. Why is there so much ascension? The main reason is that on the traditional Wi-Fi network, multi-user competition is mainly in the time domain. The more users are, the more likely the conflict occurs in the time domain. WIFI6 introduces the OFDMA technology, which allows users to schedule from two dimensions: Time and frequency. Because scheduling does not conflict in the frequency dimension. OFDMA allows multiple users with different bandwidth requirements to be provided at the same time, thereby effectively utilizing the available spectrum. Therefore, the scheduling efficiency of multiple users can be improved. The WIFI6 supports upstream and downstream OFDMA transmission, and the uplink and downlink MU-MIMO improves the air interface capacity. According to the working mechanism, OFDMA increases the air interface efficiency, which greatly reduces the delay of applications. It provides higher transmission efficiency and better effect for small data packets within the working signal-to-noise ratio (SNR) range, and is suitable for scenarios with wireless voice or similar applications. MU-MIMO improves system capacity. It is more efficient to transmit large data packets in high signal-to-noise ratio (SNR) conditions. It is suitable for video, web browsing, office scenarios, and applications. Therefore, WIFI6 can access 1024 terminals per AP, and the number of concurrent users increases by four times.
3. Low latency
To improve the system performance and the effective use of spectrum resources in the dense deployment solution, the WIFI6 standard implements the space reuse technology. It uses the BSS Color technology to dye different APs on the air interface. When detecting the 802.11ax frames of different APs, the client checks the BSS color bit in the MAC header, determines the AP to which the AP belongs, and determines the AP to communicate with. In this way, different users can communicate at the same time under the same channel. The WIFI6 standard reduces the average service delay by 50% and reduces the service delay to 20ms. The 20ms is brought by the Wi-Fi 6 standard. After the Huawei SmartRadio intelligent application acceleration technology is used, the service delay can be reduced to 10ms.
4. Low power consumption
The TWT power-saving technology is mainly used to prolong the life of the live battery of the IoT device. The energy-saving mechanism enables the IOT device to be in a dormant state for as long as possible, so as to achieve extremely low power consumption. After the TWT protocol is set up, the site does not need to receive Beacon frames. Instead, it wakes up according to a longer period to save energy.
That's all about the new WIFI6 technology. Thank you!
