When you go to your Roku Wireless Secret Screen, you will see a number of parameters on display. The picture below shows that the Roku system is connected to channel 11 of the 2.4 GHz Wi-Fi network.
The Received signal strength value is -43 dBm (deciBel milliwatt) while the noise value is -85 dBm.
The difference between the two is referred to as the signal-to-noise ratio (SNR).
Two dBm values can be subtracted from one another to give a result in dB. It represents the ratio of the two linear values – in this case signal to noise.
SNR = RSSI – Noise
SNR = -43 – (-85) = 42 dB
However the application reports SNR = 37 dB. This is 5 dB lower.
The difference is because the SNR computation is made over a wider bandwidth than just the signal of interest and as a result the noise levels are higher.
What’s a good level of RSSI?
The table below shows how RSSI and signal quality are related. The scale is split into three main regions.
| RSSI Value (dBm) | Quality |
|---|---|
| lower than -90 | Very Poor signal – unusable |
| -66 to -90 | Too Low / Poor Quality |
| -65 to -51 | Okay but might have issues |
| Greater than -50 | Strong signal / Good Quality |
Ideally you want to adjust the positioning of your Wi-Fi router relative to your Roku such that the RSSI level greater than -50 dBm.
This article features some practical measurements on how the received signal strength impacts the speed of a wireless internet connection. Essentially the further away from an access point the Roku is placed, the slower the connection speed. Tests were conducted with a phone and the Wi-Fi technology is comparable to that in a Ring device.
Note also that an important metric is SNR.
The higher the SNR the better the streaming quality.
If the noise levels are elevated to -50 dBm (an extreme example), the SNR is 0 dB. In this case the Roku Wi-Fi chip won’t be able to distinguish signal from noise and the connection will be unusable.
How to improve Roku’s Wireless Connection
Here are four things you can do to improve or increase the Roku’s Wi-Fi signal strength
Reduce the distance between Roku and Wi-Fi router
While this can be challenging at times, move the router closer to your Roku device. Also where possible reduce the number of obstacles between the router and the Roku.
Use this Wi-Fi range calculator to see how RSSI changes as a function of distance. In fact you can use it as a tool to plan your placement.
Improve RSSI without moving router
A Wi-Fi extender can be used to extend the range of your Wi-Fi network by up to 2000 feet. The Netfun product in the picture below has been validated for use with Roku.
In one case, it extended the network by 150 feet. According to the manufacturer it can extend by 8000 feet. However that is very optimistic. In reality it will be a function of the placement, environment, data throughput and interference conditions.
Pick a different Wi-Fi channel
Get a Wi-Fi analyzer app for your phone to show what 2.4 GHz Wi-Fi channels are being used around you. Find a channel that’s used the least, and set your 2.4 GHz Wi-Fi to that. Don’t use the Auto setting on your router.
Channels 1, 6 and 11 are non-overlapping so it’s best to pick one of them. Most routers are set to channel 6. Try changing it to 11.
Use 5 GHz Wi-Fi
The Roku Express 3930CA only supports 2.4 GHz band while the newer Roku Express 4K 3940CA supports both 2.4 GHz and 5 GHz Wi-Fi.
As well, Streaming Stick, Streambar and Ultra support both 2.4 GHz and 5 GHz bands. If you are in the process of making a decision on which device to buy, we recommend picking one that supports both bands.
In general 5 GHz Wi-Fi has shorter range but faster data rates and lower levels of RF interference.
Additional Related Reading
- This post delves a little deeper into the sensitivity of a Wi-Fi receiver.
- If RSSI is a positive number from 0 to 255 (for example), use this calculator to find the equivalent dBm value.