My ISP offers 300M/100 Mbps internet. The speed test results look reasonable (like 260/100 Mbps) when I test on a PC wired connected to the router (Linksys EA8100).
However, when I test speeds on Android phone, ipad and PC wirelessly connected to the router, the speeds are something like 90/98 Mbps if the clients are very close to the router (wifi signal is excellent). The speed will be like 12/76 Mbps if the clients are not that close to the router (say two walls apart, wifi signal is good or fair). I tried disabling the windows firewall but got the same result.
I also tried another two routers (Vodafone HG659b) and got the same problem. This suggests the problem maybe is from the ISP, however as the wired connection speed is so reasonable, I don't think I can blame the ISP. Are all these routers have a common bug?
Other people suggest a wifi interference, however the upload speed is very good and reasonable.
Wifi bandwidth is much less deterministic than wired connections as it depends on so many factors including the physical environment (proximity, building materials, RF noise/interference in the area, etc.).
What you are seeing is not likely a bug, but rather a limitation based one or more aspects of your setup. If we eliminate environmental aspects (which could have a significant impact), there are other things:
For example, the device(s) you are using to test the bandwidth may or may not have wifi hardware that supports higher speeds, or it could be an issue with the bandwidth of the networking subsystem and/or processor within that device.
Other factors include the band (5GHz vs 2.4GHz) and the channel bandwidth (20/40/80/160 MHz) -- in theory, the higher the bandwidth, the faster the connection. However, it also means that you are more likely to encounter interference from neighboring devices or general background. The tuning of other parameters for the radios can also have an impact on actual speed.
If the ISP is delivering the bandwidth you expect when testing on wired, there is no way that it can be blamed for issues with wireless speeds. That's like blaming the municipal water utility for a leaking faucet in your bathroom.
You can't really expect symmetric bandwidth on all devices, especially with mobile devices as the distance to the AP increases. For example, a given device may not have particularly sensitive antennas and receiver circuits, whereas the AP is well tuned and optimized for this. Silly analogy -- think about talking into the wind -- someone upwind of you would have a hard time hearing you, but you might be able to hear them really well since you are downwind.
Yeah, but I am not talking about only one wifi client. I tried on Android phone, ipad and PC wirelessly connected to the router. They all have such a problem.
I just noticed the same behaviour with my Pixel 4a 5G with Linksys EA7300. I have a 300/180 up/down internet connection and when I go into the bathroom which is further and has some other obstacles in the way, the download drops to 100 (sometimes less) but the upload is going strong at 180.
In addition that behaviour is not present when I do the same test with my laptop (Macbook pro 13).
