Why does this affect me? For two reasons. First most every device out there is using the 2.4Ghz band for Wi-Fi and some devices such as cordless phones and microwaves (yes the one in your kitchen.) use this frequency. Second you have routers that transmit on both and devices that also transmit on both.
The first problem is that there are only 12-14 channels available to the 2.4Ghz band width and if you use an app to tell you whom is using what channel next to you, you will likely see a plethora of devices on every channel. In my experience there are usually 5-7 channels that are overwhelmed since most people let their routers auto decide which channels to use. There are apps out there that will show you which channels are used and you can pick one for your router that, over time, is used the least.
The second problem is something that doesn’t get addressed that often is devices and routers that can offer both bands (2.4 and 5Ghz). If you set it up correctly this is not an issue. But by trying to over-simplify your Wi-Fi you can create your own problem. If both the router and device (laptop, phone, tablet…) are setup to use both then setup auto connects to both on the device the device is likely to flip flop between the two bands and will result looking like a very unstable internet connection. Since most newer routers and devices do support both this can be very frustrating. The simplest way around this is to forget or unsubscribe to one of the two bands.
The pros to using 2.4Ghz are its high availability and ability to go longer distances through walls and other barriers.
The cons to using 2.4Ghz are so many things that occupy that bandwidth.
The pros to using 5Ghz are less devices clogging the airwaves and better performance and the fact that both 802.11a and 802.11b cannot use it. See my earlier article about this.
The cons to using 5Ghz are that it doesn’t go through walls and other barriers as easily as 2.4Ghz and therefore range may be a limiting factor. Also even though it is listed as a pro the fact that 802.11a and 802.11b cannot connect to it may mean that you lose some of your older devices.