Hi Everyone,
Recently I shared some articles on the Wifi6 and was told that since Wifi6 is a new technology and there aren't many devices that support WiFi6, how effective is it in the real scenario. Today I'll be explaining how WiFi6 reduces the network latency and it is more dependent on the protocol itself and not dependent on the end-device.
Wifi5 uses OFDM which is like a single lane without traffic lights where multiple users compete for resources in a disordered manner. While Wifi6 uses a new and improved version called OFDMA which effectively reduces conflicts and improves spectrum utilization. OFDMA is like multiple lanes with traffic lights, resources are scheduled for multiple users in an ordered manner. Using this, spectrum utilization is improved by more then 30 times.
OFDMA technology is adopted in the Wi-Fi 6 standard to improve the spectrum utilization. In the traditional manner, when each STA sends data (regardless of the size of the data packet), the entire channel is occupied by a large number of small-sized management frames and control frames. This is like a big bus carrying only one passenger. OFDMA technology divides a radio channel into multiple sub-channels (subcarriers) in the frequency domain to form resource units (RUs). User data is carried on the RUs and does not occupy the entire channel, thereby implementing simultaneous transmission of data from multiple STAs during each time segment. STAs no longer need to wait in queues or compete with each other, which improves the efficiency and reduces the queuing delay. For example, at mode of HT20, 26 small seats (subcarriers) are bound together to form a minimum RU. One RU provides 2 MHz bandwidth (also called 26-tone RU). The bus (20 MHz) can carry a maximum of nine passengers (nine concurrent users) at the same time.
Second technique that Wifi6 uses is called BSS Coloring which is used to reduce co-channel interferrance. In Wifi5, CCA (Clear Channel Assessment) power adjustment was used where users on same channel need to queue up for the channel resources. While in WiFi6, BSS (Basic Service Set) coloring technique is used where different users in the same channel are assigned different colors so maximum users can send data at the same time. This helps decrease the co-channel interference by at least 30%.
This technique is especially useful where customers doesn't have many channels available and they need to reduce the co-channel interferrence using AP power level adjustment. This technique can also be used in high raise towers where there is a lot of signal propagation in-between floors.
I hope it was helpful for you. Please let me know in case of any queries.
Sources for more research: Huawie Wifi6
