The 5Ghz band is normally used for wifi5/wifi6 and supports higher data transfer speed. Wifi5 works exclusively on 5ghz band only, but wifi6 can work on both 2.4 and 5ghz.
However you might be surprised to know that even wifi4 (802.11n) supports 5ghz band though it will deliver its lower speed only.
A lot of times it might happen that you are using a 5ghz band connection to your wifi router but still getting slow speed. This article is about this common problem and what can be done to fix it.
Not getting full speed on 5Ghz wifi
It happened to me as well, when i tried transferring a large file from my Ipad Air 4 (which was connected on 5Ghz band) to my desktop (which was on wired ethernet). The transfer speed was very low and i was puzzled. I was pretty sure that both the Ipad and my desktop were capable data transfer speed much higher than what i was seeing.
Its true that the wifi connection speed diminishes over distance, but even when i tested keeping the devices close to the router, i could never exceed 300 mbps. However my isp provides me 600 mbps which i could confirm on a wired ethernet connection, but not on wifi.
Upon deeper inspection that the real cause were my ethernet cables and ethernet switches which were limited to only 100 mbps which were causing slow download speed. Recently i upgraded my home network equipment and got fast speeds on all devices including wired and wifi.
I tested it with iperf and have talked about the results in this article.
A wifi5 connection on 5ghz band can achieve a max throughput of 866.7mbps and wifi6 can do upto 1200mbps. However the actual speed will always be atleast 25% less due to radio signal attenuation and interference.
Find and Fix the Cause
There are a number of elements in your network setup and the final speed will always depend on the slowest device in the link chain. The list of equipment that affect your network speed include:
- 1. Router
- 2. Switches
- 3. Ethernet Cables
- 4. Ethernet card on laptop/computer
- 5. Wifi device capability
- 6. Wifi MCS standard being used (depends on numerous factors again)
The Router
If you want high speed on 5ghz speed then just having a 5ghz device is not enough, you also need a capable
The first thing you need to check is your router's maximum supported speed. Older routers supported only upto 100-300mbps on single, and modern routers with wifi6 (802.11ax) can support over 1000mbps (1gbps) on single wifi device.
My ISP had provided me with this Optic Fiber router: Huawei HG8145V5. It supports 1G Ethernet and Wifi 802.11ac 5Ghz.
If your router says something like N150 or N300, it means its a 802.11n router (note the "N") which is wifi4 and max speed is 150mbps or 300mbps. Typical wifi5 routers can support upto 866.7mbps on a 5ghz wifi5 connection. So check the specs of your router and see if it can support that.
Switches
The speed of the switches will matter only if you are transferring data to another device on the network that is connected via the switch. Most cheap switches are actually only 100mbps rated. You need to get a gigabit switch. There are plenty of options from both dlink and tplink.
If you are just browsing the web over wifi, the connection just go through your router to the internet and the switch speed does not matter.
Ethernet Cables
Ethernet cables connect pcs/laptops with switches and routers. Ethernet cables have their on speed limits depending on whether they are Cat5/5E/6. On any modern setup you should always have Cat6 cables, as they support minimum of 1gbps and upto 10gbps upto short distances.
If you are using older cat5 cables or even poor quality cat5E cables your speed would drop to 100mbps. On a linux system you can check the connection speed using the ethtool command:
$ sudo ethtool enp1s0 | grep -i speed
Speed: 1000Mb/s
$
Replace the enp1s0 with your ethernet interface name. Supported speed can be checked with ethtool as well. Just run the following command:
sudo ethtool interface_name
Distance
The speed of your wifi connection diminishes over distance, and this effect is more pronounced with the 5ghz band. The 5ghz band has SHORTER range compared to 2.4ghz, so the speed would drop much more drastically as you move away from the router.
So if you want fast speed with 5ghz frequency band, you have to be close to the router, or if you want to work further away, then install an access point to make the 5ghz signal stronger near you.
If you want to learn more about how distance affects wifi speed, I suggest reading this article:
https://www.duckware.com/tech/wifi-in-the-us.html
Spatial Streams
The wifi speed depends on numerous factors like MU-MIMO configuration (number of spatial streams being used). The speed is directly proportional to the spatial stream count.
Most smartphones use only 1 spatial stream ( called 1x1 connection) when connecting to a wifi router. Most laptops however use 2 spatial streams. Due to this you would get double wifi speed on laptops compared to smartphone.
Note that for multiple spatial streams to work, you actually need a router with MIMO support (2x2 or higher)
Check connection mode (Wifi standard)
A lot of times devices would simply connect using wifi4 ( 802.11n) on 2.4ghz band without the user being aware. In such a situation you would again get less speed. So you should check your device wifi connection parameters to ensure that you are connected on wifi5 or higher.
On android there are plenty of wifi analyzer apps that can do this. For example I use this one: WiFiman.
On Windows and Linux (Ubuntu or Fedora) you can check connection parameters from network information.
Conclusion
There are certain factors that cannot be changed. For example on smartphones you cannot get higher 5ghz speeds because they use only single spatial stream connection compared to laptops that use 2 spatial streams.
