The modern home is filled with gadgets that require a stable connection, but users often experience slow speeds or sudden connection interruptions. Understanding How to check the quality of a WiFi signal, is becoming a key skill for comfortable work and entertainment. Simply seeing a network icon on a smartphone screen is no longer sufficient, as it doesn't reflect the actual bandwidth.
Poor reception can be caused by a variety of factors, from physical barriers like walls and mirrors to electromagnetic interference from household appliances. In this article, we'll explore technical metrics, learn how to use professional tools, and discover why your router may be underperforming.
Before embarking on complex measurements, it's worth noting that even a basic understanding of the physics of radio wave propagation can help you quickly pinpoint the problem. 2.4 GHz waves And 5 GHz They behave differently, and diagnostics must take these differences into account. Let's look at the key indicators to look at first.
Key metrics for evaluating a wireless network
The first thing you'll encounter when troubleshooting is the signal level, measured in decibel milliwatts (dBm). This is a logarithmic unit of measurement, and its values are always negative. The closer the value is to zero, the better the signal: for example, -30 dBm is ideal for being close to the router, while -90 dBm means there's practically no connection.
The second critical parameter is the noise floor. It measures the background electromagnetic radiation in the air. If your signal level is -70 dBm and the noise floor is -75 dBm, don't expect stable operation. The difference between the signal and the noise, called SNR (Signal-to-Noise Ratio), should be as large as possible for high-quality data transmission.
It's also worth paying attention to data transmission channels. In the 2.4 GHz band, a "mess" of neighboring networks often occurs, leading to collisions and packet loss. In the 5 GHz band, there are more channels, but their range is shorter due to the higher frequency.
⚠️ Attention: Don't rely solely on the number of bars on your phone's screen. Different device manufacturers (Apple, Samsung, Xiaomi) calibrate their signal strength display differently. While an iPhone might show a full signal, an Android smartphone might be losing connection.
For an accurate assessment, you need specialized software that displays digital values. Knowing that -65 dBm is the threshold for 4K video streaming will help you objectively assess the situation in a specific room.
Software diagnostic methods on PCs and smartphones
The most accessible way check the quality of the WiFi signal — Use built-in operating system tools or free utilities. Windows computers have a hidden but very informative command line that provides more information than the standard interface.
To get a detailed report, open the command prompt (cmd) and enter the command netsh wlan show interfacesIn the list that appears, find the "Signal" line, where the value will be shown as a percentage. However, for a more in-depth analysis, it's better to use the graphical interfaces.
☑️ Checking the signal on a PC
On mobile devices, the situation is even simpler thanks to the variety of apps. For Android, an excellent choice is WiFi Analyzer or WiFi Man from Ubiquiti. These apps create real-time graphs showing how the signal fluctuates as you move around your home.
iOS users (iPhone, iPad) will have to use the app AirPort Utility from Apple. You need to enable a hidden option in your phone's settings to activate scanner mode. This will allow you to see the signal strength in dBm without jailbreaking.
It's important to take measurements at different points in the room, especially in areas where you plan to use the internet actively. Record the readings so you can compare before and after moving the router or changing settings.
AirPort Utility's Secret Mode on iOS
To enable the WiFi scanner on your iPhone, go to your phone's Settings (not the app itself), find AirPort Utility, and turn on the "WiFi Scanner" toggle. Then, quickly tap the router's name in the app to view its technical specifications.
Frequency and channel load analysis
Communication quality depends not only on the transmitter power but also on the airwaves' clarity. Imagine trying to talk to a friend in a quiet room or at a rock concert. In the first case (a clear channel), you'll be heard perfectly; in the second (a busy channel), even your shouts might be inaudible.
Channel visualization helps you understand what frequency your network and your neighbors are using. In the 2.4 GHz band, there are only three non-overlapping channels: 1, 6, and 11. If everyone around you is using channel 6, interference occurs, reducing your actual speed.
Use network analyzer apps to view a graphical representation of your networks. The curves of neighboring networks should not overlap with yours. If this happens, you must manually switch the router to a clear channel through the web interface.
⚠️ Attention: The router's automatic channel selection often doesn't work correctly. The router might select a "free" channel at night when neighbors have turned off their networks, but in the morning, when everyone wakes up, that channel is overloaded.
The situation is better for the 5 GHz band: there are more channels and they are narrower, which reduces the likelihood of collisions. However, it is important to check the channel width. Setting the width 80 MHz or 160 MHz provides high speed, but increases the risk of interference. In apartment buildings, it is sometimes more cost-effective to choose 40 MHz for stability.
Physical factors affecting the coating
Radio waves are a physical object that interacts with the surrounding world. Knowing the materials your home is built from helps predict "dead zones." Some materials absorb signals, while others reflect them, creating echo chambers.
The greatest attenuation is introduced by:
- 🧱 Reinforced concrete walls with reinforcement: can block up to 90% of the signal, especially at 5 GHz.
- 🪞 Mirrors and tinted windows: The metal coating acts as a screen, reflecting the waves back.
- 💧 Aquariums and water: Water absorbs radio waves very well (that's why a microwave heats food containing water).
- 📺 Household appliances: An operating microwave oven or high-power refrigerator can create strong interference in the 2.4 GHz band.
The router's placement also plays a crucial role. Hiding it behind a TV or placing it on the floor will inevitably reduce signal quality. Router antennas emit a signal in a donut-shaped (toroidal) pattern, so vertical placement is usually optimal.
Metal objects in close proximity to the antennas (such as a PC case or a metal shelf) can create a "shadow." Moving the router 20-30 centimeters away can sometimes work wonders, increasing the signal strength by 5-10 dBm in the adjacent room.
Signal level standards and compliance table
To avoid guessing whether your signal is good or bad, it's helpful to have a reference chart handy. dBm numbers allow you to objectively assess the feasibility of specific tasks, such as video calls or online gaming.
Below is a table showing the dependence of connection quality on signal level:
| Signal level (dBm) | Quality | Possibilities |
|---|---|---|
| -30... -50 | Excellent | Any task, maximum speed, 4K/8K streaming |
| -51... -60 | Good | Stable performance, HD video, and lag-free online gaming |
| -61... -70 | Average | Surfing, email, SD video, occasional interruptions possible |
| -71... -80 | Bad | Only text, messengers, video will buffer |
| -81... -90 | Critical | Unstable connection, constant disconnections, difficulty logging into the network |
Please note that a slightly weaker signal is considered normal for the 5 GHz band than for 2.4 GHz due to the attenuation characteristics of high-frequency waves. However, the data transfer rate on 5 GHz at -70 dBm will still be higher than on 2.4 GHz at -60 dBm.
If your measurements show values below -75 dBm in working areas, you should consider boosting the signal or changing the network topology. Ignoring these indicators will result in constant discomfort while using the network.
Troubleshooting and network optimization
After you checked the quality of the WiFi signal Once problem areas have been identified, the optimization phase begins. Simple steps can often significantly improve the situation without purchasing new equipment.
Start by updating your router's firmware. Manufacturers are constantly improving signal processing algorithms and fixing bugs. Go to the web interface (usually at 192.168.0.1 or 192.168.1.1) and check for updates.
If channel overlap is the issue, force the network to switch to a less congested one. For 2.4 GHz, select only channels 1, 6, or 11. For 5 GHz, you can use automatic mode, but sometimes manually selecting a less congested channel yields better results.
⚠️ Attention: Router interfaces (TP-Link, Asus, Keenetic, MikroTik) are constantly being updated. The location of channel and transmitter power settings may differ from that described in the manual. Look for the "Wireless," "WiFi Settings," or "Wireless Network" sections.
As a last resort, if the signal strength doesn't physically penetrate the walls of your home, consider installing a mesh system or repeater. This will create a single, seamless network with coverage throughout your entire home.
What is the difference between a repeater and a mesh system?
A repeater simply repeats the signal at a high speed. A mesh system is a set of smart nodes that create a unified network where devices switch between nodes without losing connection, maintaining high speed.
Frequently Asked Questions (FAQ)
Why is WiFi speed low even though the signal is full?
The total signal (number of "bars") only indicates the connection strength between the device and the router, not the channel's throughput. Low speeds can be caused by: channel congestion from neighbors, speed throttling by the ISP, older WiFi standards (e.g., 802.11n instead of ac/ax), or background downloads on other devices.
How to check WiFi speed on TV?
On Smart TVs (Samsung, LG, Android TV), built-in speed tests are often missing or don't work correctly. The best solution is to install a network analysis app (e.g., WiFi Analyzer on Android TV) or use online services like speedtest.net through the built-in browser, if available.
Does weather affect the quality of home WiFi?
Weather doesn't directly affect indoor signal strength, as the walls protect against external factors. However, a strong thunderstorm with lightning can create powerful electromagnetic pulses, causing short-term interference. Humidity also theoretically affects 5 GHz signal attenuation, but this isn't noticeable within an apartment.
Is it worth buying a signal booster (antenna) for a router?
Replacing the stock antennas with more powerful ones (high-gain, dBi) only makes sense if your router supports this option and has removable antennas. However, this will only redistribute the antenna pattern. For truly expanded coverage in larger apartments, using mesh systems or PowerLine adapters is more effective.