The world is changing every day. As I write this, five states in the United States have already asked everyone to "shelter in place," and multiple other countries are also under similar forms of lockdown due to the Coronavirus. Suddenly everyone is at home almost 24x7. Our home WiFi is no longer just used for entertainment. Now it's one of our only links to the world - to our extended family, friends, co-workers, and boss.
We all need our WiFi to work — Here are three steps everyone can take to be a good WiFi neighbor.
Ever since WiFi began in the 2.4 GHz band every WiFi access point and router has supported 2.4 GHz. It used to be that many WiFi devices only had 2.4 GHz, and many Internet of Things (IoT) devices still only have 2.4 GHz WiFi. But all recent smartphones, media streamers (Apple TV, Roku, etc.), and laptops have both 2.4 GHz WiFi and 5 GHz WiFi.
If you don't have Internet of Things devices in your home, there's a good chance that you don't need to have 2.4 GHz WiFi enabled on your WiFi access point. If you don't need it we recommend disabling it. If you aren't sure if you need it, you can experiment by disabling it and seeing if anyone complains.
Every access point sends a broadcast message called a "beacon" 10 times per second telling the world about itself. Beacons are sent at super slow speeds so that all devices, no matter how old and limited can understand the beacon. Over the years as WiFi access points have added more and more capabilities, the beacons have gotten longer and longer. In 2.4 GHz beacons are sent at the slowest speed possible, which is 1 Mbps, and in 5 GHz beacons are sent at 6 Mbps, so beacon overhead is less of a problem in 5 GHz than it is in 2.4 GHz.
A modern WiFi access point can consume up to 4% of all available airtime just sending beacons to any device that will listen. Now 4% may not seem too bad, but imagine 10 access points on the same channel, each one sending 10 beacons per second and suddenly 40% of the airtime is being used up before a WiFi device even tries to connect.
Here is a guide to changing settings on your wireless access point.
In 2.4 GHz the channels are numbered funny. WiFi networks need at least 20 MHz channel width, but channels are numbered every 5 MHz, which means that channel 1 overlaps with channels 2, 3, and 4. With overlapping channels WiFi devices cannot understand each other and cannot cooperate to determine who should talk next, so WiFi devices on overlapping channels end up trying to talk at the same time, which garbles the transmissions from both devices. Notice in the screenshot below how the network centered on Channel 3 overlas with the networks on channel 1 and channel 6.
Overlapping channels is the biggest cause of poor performance in the 2.4 GHz band and it will not only cause your WiFi to have poor performance, it will impact all the WiFi networks on the channels that your WiFi overlaps with.
In the United States it is best practice to ONLY use channels 1, 6 and 11, because these channels don't overlap. In Europe, Asia, and other countries that have channels 12 and 13, it is best practice to use channels 1, 5, 9, and 13. Sometimes the U.S. practice of 1, 6, and 11 is used outside the United States, so if channels 12 and 13 are available in your country, use your best judgment as to which set of standard channels is being used in your WiFi environment - either 1,6, and 11 or 1, 5, 9, and 13.
If you are using any other channel number (e.g. channel 2) then you should stop right now and change the channel to a standard channel.
Originally all 5 GHz WiFi channels were 20 MHz wide, but 802.11ac (WiFi 5) introduced the ability to combine channels together into 40 MHz, 80 MHz and even one 160 MHz wide channel. Wide channels enable faster speeds, but they also reduce the number of channels that are available for everyone else. If everyone used 20 MHz wide channels there are 13-25 channels available without any overlap. If people use 80 MHz wide channels there are 3-6 channels available and then the 5 GHz WiFi band starts looking crowded and messy like the 2.4 GHz band does with all the WiFi networks trying to share a few WiFi channels.
802.11ac WiFi devices that are using wide channels will still decide each packet whether or not to use the full channel or a small portion. For example a WiFi device using an 80 MHz wide channel may send packets that are 20 MHz, 40 MHz, or 80 MHz wide. This dynamic ability is helpful in reducing the amount of overlap with other networks, but it also takes up some airtime to coordinate. So if you are in a dense environment like an apartment building where there are at least six WiFi networks close to each other we recommend everyone spreading out on their own WiFi channel and only use 20 or 40 MHz wide channels to reduce overlap.