WIFI6

　　5G has three major scenarios: eMBB, mMTC and URLLC, which are aimed at future high-bandwidth video services such as 4K/8K, VR/AR and the Internet of Everything. The direction of Wi-Fi 6 is consistent with 5G:

　　•Wi-Fi 6 supports multi-user high-speed concurrency, and can support ultra-high-definition video applications in user-dense scenarios such as homes, stadiums and other public places.

　　•Wi-Fi 6 optimizes device power consumption and coverage capabilities, and can better support IoT applications such as smart homes and smart cities.

　　Compared with Wi-Fi 5, the main new technologies introduced by Wi-Fi 6 are as follows:

　　OFDMA: Unlike Wi-Fi 5, which uses OFDM technology, Wi-Fi 6 borrows the OFDMA technology used by cellular networks. Multiple terminals can transmit in parallel at the same time without waiting in line or competing with each other, thereby improving efficiency and reducing latency.

　　OFDM: When a terminal device uploads or downloads data, it occupies the entire wireless channel in each time period.

　　OFDMA: OFDMA divides the wireless channel into multiple subchannels (subcarriers) in the frequency domain to form time-frequency resource blocks. User data is carried on each resource block instead of occupying the entire channel, so that multiple users can transmit in parallel in each time period without waiting in line or competing with each other, which improves efficiency and reduces waiting time.

　　It is estimated that by 2020, an average family will have 50 wireless connected devices. Wi-Fi 6 introduces flexible OFDMA technology to support wireless access to a variety of devices such as doorbells, refrigerators, and light bulbs.

　　Improve coverage

　　Like cellular networks, the bottleneck of wireless coverage lies in the uplink. In Wi-Fi networks, APs usually have higher transmission power and more antennas, and the downlink coverage distance is long. At the same time, the AP remains plugged in to the power supply, so there is no need to worry about power consumption; but for mobile phones, tablets and other IoT terminals, the transmission power and number of antennas are limited, which affects the uplink coverage, and the battery life must be optimized.

　　To this end, Wi-Fi 6 optimizes the uplink signal coverage, using a method similar to NB-IoT Internet of Things technology, that is, the terminal concentrates its energy in a narrower 2MHz channel and improves the uplink coverage by increasing the uplink power spectrum density.

　　Wi-Fi 6 expands the coverage range, which is conducive to its move from indoors to outdoors, paving the way for the future deployment of campus Internet of Things, smart cities, etc.