Performance Tweaks on your Home Router
Most modern routers support dual band, one on the 2.4 GHz band and one on the 5 GHz band
2.4 GHz band is the long range band and 5 GHz band is short range band. If your router is in the living room and you go out in to your balcony, the signal strength of 2.4 GHz band is higher compared to 5 GHz band. The higher the signal strength the better the communication with the router
Here are a few settings worth tweaking to improve the performance, efficiency, safety of your router and connected devices
Smart Connect or Band Steering
If your router is a dual band router, it operates on two bands simultaneously and each band has its own Wi-Fi name/SSID. You will be able to connect to any band by selecting that specific SSID. You might be have something like this
BandWi-Fi name
2.4 GHzTP-Link_Home_2.4G
5 GHzTP-Link_Home_5G
Some devices like old televisions, desktop computers, some single board computers etc can communicate only on the 2.4 GHz band. They will not be able to see the 5 GHz band
Modern devices like laptops, smart phones, smart televisions etc can communicate on both the bands. Once you connect any of the these devices to a particular band, they stick with that band and usually don't switch to the other band until you manually perform the switch. Some devices switch automatically when they detect a very low signal strength on the band they are connected to
When you enable smart connect on your router, it shows only one SSID for both the bands, and the devices in your home just see one name instead of two and they connect to this name. If you are browsing on your mobile phone in your living room, your mobile phone will be communicating on 5 GHz band and if you move in to your balcony, it would communicate on 2.4 GHz band. You don't have to do anything manually, this switch between bands happens seamlessly in the background and you would not visually know which band your device is communicating on as there is only one SSID for both the bands
The advantage of this is that you don't have to do anything as everything is seamless but it has one drawback. Some devices when they switch to long range 2.4 GHz band they don't switch back to 5 GHz band even when you are closer to the router. So, your device is stuck with the 2.4 GHz band which has a very narrow bandwidth and your internet feels too slow. Ofcourse your phone will switch back to 5 GHz band when you turn off the Wi-Fi on the phone and turn it on again
Quality of Service (QoS)
QoS is a feature on your router that prioritizes network traffic for devices or applications with higher priority
Priority can be device based (Laptop, Mobile Phone, TV etc) or application based (Voice calls, streaming apps, gaming applications etc)
Low end routers might support only device based settings and some high end routers might support both application and device based priority
When you are on a video conference with your colleagues and at the same time your kids are watching a movie on Netflix and if you had not defined QoS, your router would treat both the traffic equally and you might experience intermittent disturbance in your video call
If you define priority for voice calls over streaming apps like Netflix, your router would prioritize voice calls over streaming. Similarly, if you are not able to narrow down to an application and instead prefer to prioritize a device like your home server or your work laptop, the router would prioritize traffic for that device and all the applications running on it
In certain situations it is advantageous and sometimes it becomes an overkill
Wi-Fi Protected Setup (WPS)
Enabling this setting on your router allows devices to connect to your router with out typing the Wi-Fi password. It compromises the safety of your router
This is useful for devices that don't have a screen like smarthome cameras, wireless printers, Wi-Fi range extenders etc
If you want to connect a device, you press the WPS button on the device and then you press the WPS button on your router. The router will pair with the device by transmitting the password securely to the device
If this setting is enabled, anyone can connect to your router based on the setup method selected
If you selected push button method and if someone can get closer to the router and can press the WPS button when you are not noticing, they will be able to connect a device to your router with out entering password
If you selected pin number method and if someone gets hold of the pin or cracks it (it is an 8 digit numeric code and it is possible to crack the pin by using bruteforce tools), they will be able to connect a device to your router with out entering password
Bands, Channels and Channel Width
Let us assume 2.4 GHz band as a very long but narrow pipe and 5 GHz band as a short but very wide pipe
By theory we know a wider pipe can carry large amount of fluid and a narrow pipe can carry small amount of fluid at any given time
We can also assume 2.4 GHz band as a narrow road with fewer lanes and 5 GHz band as a wider road with many lanes
Imagine lanes as channels and channel width as width of the lane
A narrow road has narrow lanes and a wider road has wider lanes
Narrow road is prone to traffic jam where as a wider road is not
Bands and Channels
2.4 GHz band travels longer distance by penetrating walls, that is how you get a decent signal eventhough your router is in the living room and you are connected to the router from the balcony which is two to three rooms away from your living room
Long distance travel by penetrating through walls is good until it becomes not so good, because 2.4 GHz band is used by many devices
2.4 GHz band is used by wireless devices like the wireless keyboard, bluetooth headphones, cordless phones, RC toys, smart switches, microwave etc
Apart from the above devices, add your neighbor's (living above, below or adjacent to you) router and other devices operating on 2.4 GHz band
In summary the narrower road is unfortunately used by many people located in the same neighborhood
In technical terms it is called interference and it is of two types
Co-Channel interference happens when you and your neighbor are on the same channel
There are 11 channels in 2.4 GHz band. In some regions there are 14 channels. If you and your neighbor are on channel 6 and it is currently being used by your neighbor, your router has to wait until the channel becomes clear. This wait time is usually negligible but it becomes compounded when it happens too frequently
If we go back to our road analogy, imagine you and your neighbor have to move the car out of the garage but both of your garage roads are connected to a common lane. When both of you decide to move the car out of the garage at almost the same time, one of you has to wait depending on who has moved their vehicle first
Out of the 11 channels only 1, 6 and 11 are non-overlapping channels. All other channels are overlapping
Overlapping channels lead to Adjacent-Channel interference also known as signal bleeding
Let us say you and your neighbor are on channels 2 and 3, technically you should be able to communicate simultaneously because they are different channels, but as 2 and 3 are overlapping channels, simultaneous communication will result in constant retransmission
Let us go back our road analogy again, now your garages are using roads that don't lead to a common lane, but instead to two adjacent lanes. As they are adjacent lanes you and your neighbor should be able to get your cars out on to the main road simultaeously with out having to wait. But as the lanes are adjacent and slightly overlapping, your car and your neighbor's car can't be on exact same location at the same time, if this happens your cars would scratch each other
As we are looking at one car at a time it still looks possible in both the cases (Co-Channel and Adjacent-Channel), but our routers, laptops, mobile phones and other devices send several packets at any given time, so the channels are always busy
5 GHz band has 25 non-overlapping channels and each channel is 20 MHz wide
Manual Channel Selection
To understand which channel is crowded
Execute the below command if you are running Unix
nmcli -f BSSID,SSID,SIGNAL,BARS,CHAN device wifi list
nmcli -f BSSID,SSID,SIGNAL,BARS,CHAN device wifi list | awk 'NR==1 {print $0, "DBM"} NR>1 {p=$3; dbm=(p/2)-100; print $0, dbm " dBm"}' | column -t
Execute the below script in Power Shell if you are running Windows
netsh wlan show networks mode=bssid | ForEach-Object {
if ($_ -match 'SSID\s+\d+\s*:\s*(.*)') { $ssid = $Matches[1].Trim() }
if ($_ -match 'BSSID\s+\d+\s*:\s*(.*)') { $bssid = $Matches[1].Trim() }
if ($_ -match 'Signal\s*:\s*(\d+)%') { $signalPct = [int]$Matches[1] }
if ($_ -match 'Channel\s*:\s*(.*)') {
$channel = $Matches[1].Trim()
# Calculate dBm using the formula: (Signal / 2) - 100
$dbm = ($signalPct / 2) - 100
[PSCustomObject]@{
WiFi_Name = if ($ssid) { $ssid } else { "[Hidden Network]" }
Channel = $channel
Signal = "$signalPct%"
Signal_dBm = "$dbm dBm"
}
$bssid = $signalPct = $channel = $null
}
} | Format-Table -AutoSize; Read-Host "Press Enter to exit"
Note: If Windows blocks it due to an "Execution Policy" error, run
If we observe the output from the above scripts, we will be able to understand which channel is used the most. The channel that appears more number of times is the channel that is used most in the neighborhood. But that doesn't alone mean we should avoid that channel. Along with that we should also look for Signal value in dBm
For us to decide which channel to avoid, we should understand how the router determines which channel is clear
Router performs a routine called Clear Channel Assesment before it decides to use a particular channel
It is a two step process
- Signal Detect (SD)
- Energy Detect (ED)
Threshold level for SD is -82 dBm. Any signal weaker (e.g., -90 dBm) than the SD threshold, the router considers that channel as clear. If it is stronger (-75 dBm) than the SD threshold, it marks that channel as busy and waits for transmission
Energy Detect step is to determine if it is a non-Wi-Fi energy source (microwave, bluetooth etc). The threshold for ED is -62 dBm. Any signal stronger (e.g., -50 dBm) than the ED threshold, the router considers that channel as busy
Now that we have uderstood how the router performs channel selection, we can easily decide which channel to avoid. The channel that repeats the most and has signal strength that equals or exceeds the SD threshold
Channel Width
On both the bands we can adjust the channel width
On the 2.4 GHz band, channel width can be set to 20 MHz or 40 MHz
On the 5 GHz band, channel width can be set to 20 MHz or 40 MHz or 80 MHz or even 160 MHz
As the width of the overall road is constant, increasing the width of the lanes will result in overlapping lanes
On a 5 GHz band if we set the channel width to 40 MHz, the router will combine 2 adjacent channels each resulting in 12 unique channels instead of 25
Increasing the channel width will increase the speed but it is prone to interference because of channel overlap
Beacon Frames
Naturally, you might have a question now, how does my phone or laptop know which channel and channel width the router is going to use for communication when channel and channel width selection is set to auto
Routers use something called a beacon frame. Routers broadcast beacon frames 10 times every second to tell their identity
A part of this beacon frame also includes the channel and channel bandwidth
Happy Routing
