Through TP-Link TL-WR845N weaken the signal and speed drops

Good afternoon, the problem is as follows. I have TP-Link TL-WR845N, provider Vodafone, tariff All at once 2019. I measure speed with Speedtest mobile application and PC in Wi-Fi environment. At normal signal the speed of PC is 20MB, mobile speed is 35-40MB.

I check the signal itself with WI-Fi Monitor application: somewhere 40 dBm, bandwidth 40MHz. The channel was chosen free from neighbors. After a while the speed drops in times. I restore through rebooting the router (power off and on after 5-10 min.). Is this a normal phenomenon or something to fix? Thank you.

Answer

Hello. 20 Mbps through TP-Link TL-WR845N is not enough. 35-40 Mbps is better, but still. And of course the speed should not drop after a while. Important point: the speed depends on the receiver (the device connected to the network) and on external factors. In this regard, it is necessary to clarify a few points:

Does the Wi-Fi speed drop simultaneously on PC and mobile devices?
Are you measuring the speed close to the router (signal is normal)?
Do you have many neighboring Wi-Fi networks in your house?
Judging by “40MHz bandwidth” you have swapped Wi-Fi settings on TP-Link TL-WR845N (as it is usually auto and the router selects 20 MHz), maybe the speed dropped because of it.
What is the speed on the cable from the router? If not, maybe it’s the provider for some reason starts to cut the speed, and accordingly on Wi-Fi it also drops.
Maybe you have noticed the connection of speed drop with connection of some devices, or performing some actions on connected clients (online games, downloading torrents, watching videos, etc.)?

Try the following:

Update the TP-Link TL-WR845N firmware.
Do a factory reset to configure the TP-Link TL-WR845N again. Do not change anything in Wi-Fi settings except network name and password.

You can write about the results in the comments below.