Unstable internet service, constant video buffering, and slow page loading speeds are classic symptoms of poor wireless coverage. Users often blame their ISP or router, failing to understand that the problem lies in the physics of radio wave propagation. To effectively resolve the issue, it's essential to first obtain accurate data on the current wireless coverage, rather than guesswork.
There are many ways to conduct signal level measurementFrom built-in operating system functions to specialized professional software, understanding how to interpret decibel-milliwatt (dBm) readings will help you properly configure your router or choose a location for its installation. In this article, we'll cover all the available diagnostic methods to help you achieve maximum home network performance.
WiFi operates in bands where even a slight change in antenna position can dramatically impact connection quality. Therefore, the first step to a stable internet connection is an objective assessment using digital indicators. Let's look at what these numbers mean and where to find them.
Interpreting signal strength readings
Before launching complex programs, it's important to understand what exactly we're measuring. WiFi signal strength is measured in logarithmic units called decibel milliwatts (dBm). Unlike the usual positive numbers, the scale here is negative, which often confuses beginners. The closer the value is to zero, the better the connection quality. For example, -30 dBm means perfect proximity to the router, while -90 dBm indicates virtually no connection.
The optimal range for comfortable operation is considered to be between -30 and -60 dBm. In this zone, you can watch 4K videos, play online games, and make video calls without any problems. If the value drops below -70 dBm, connection stability issues begin, and below -80 dBm, the network becomes practically unusable.
It is important to take into account that the indicators are influenced not only by distance, but also wall materials, the presence of mirrors, microwave ovens, and nearby wireless networks. Metal structures and thick concrete can absorb up to 90% of the signal, turning the router's powerful radiation into barely audible noise.
Checking signal strength on Windows and macOS
The easiest way to perform a basic diagnosis is to use the operating system's built-in tools. In Windows 10 and 11, you can obtain basic information without installing any additional software. To do this, go to the menu Parameters, select a section Network and Internet, and then StateHowever, the standard interface only shows the number of "sticks," which doesn't provide an accurate picture of the situation.
To get precise numbers on Windows, use the command line. Open the terminal (CMD) and enter the command:
netsh wlan show interfacesIn the list that opens, find the line "Signal Quality." It will show a percentage that can be roughly converted to dBm, but more accurate data can be obtained using third-party software, which we'll discuss below.
macOS users have an advantage: they have a hidden diagnostics menu. Hold down the key Option and click the WiFi icon in the top bar. You'll see detailed information, including RSSI (Received Signal Strength Indicator) and noise level. The difference between these values gives you an idea of channel quality.
macOS Secret Menu
If you hold down Option and click on WiFi, an advanced menu will open, where in the "Wireless Network Diagnostics" section you can launch the built-in analyzer, which will show the connection history and channel quality.
Apple computers also have a "Wireless Network Diagnostics" utility, which can be found via Spotlight (Cmd+Space). It allows you to visualize signal quality in real time and compare it to noise levels.
Mobile applications for Android and iOS
A smartphone is the most accessible tool for conducting a "walk test" (checking the signal while moving). There are many free utilities for Android that turn your phone into a professional analyzer. One of the most popular is WiFi AnalyzerIt displays all available networks as graphs, showing how congested your channel is by neighbors.
- 📱 WiFi Analyzer — a classic for Android, shows power graphs and free channels.
- 📶 NetSpot — a professional tool with the ability to create heat maps of a room.
- 📡 Fritz!App WLAN — an excellent application that works with any router and helps you find the best installation location.
iPhone owners face iOS limitations: Apple prohibits apps from fully scanning the airwaves in the background. However, there is an official solution from Apple developers – a utility AirPort UtilityTo activate the hidden functionality, you need to go to Settings phone, find in the list of applications AirPort Utility and turn on the "Wi-Fi Scanner" switch.
Once the scanner is enabled, a scan button will appear in the AirPort Utility app, displaying a list of networks and their RSSI. This is the only legal way to get accurate numbers on iOS without jailbreaking.
Diagnostics via the router's web interface
The most reliable source of connection status information is the router itself. Its admin panel displays the signal strength it sees from your devices (uplink) or from the base station (if it's a 4G/5G router). Logging in usually requires entering the address in a browser. 192.168.0.1 or 192.168.1.1.
Depending on the model (Keenetic, MikroTik, TP-Link, Asus), the path to the information may vary. Typically, the data is located in the "Status," "Statistics," or "System Monitor" sections. There, you'll see a table of connected clients with the signal strength (RSSI) for each device.
⚠️ Attention: Router firmware interfaces are frequently updated. If you can't find the option you need, check the official instructions on the manufacturer's website, as the menu layout may change.
Analyzing this data allows us to identify "weak" devices. For example, if a laptop shows -40 dBm, while a smart bulb in the same room shows -85 dBm, the problem lies with the antenna or the bulb's drivers, not the router.
Table of standards and values
To quickly assess the situation, use the following table. It will help you understand whether you need to panic or whether the signal is within acceptable limits.
| Signal level (dBm) | Quality | Description of the situation | Recommended actions |
|---|---|---|---|
| -30... -50 | Excellent | Perfect connection, router in one room | No action required |
| -51... -65 | Good | Stable operation of all services | Optimal range |
| -66... -75 | Average | Speed drops are possible | Check the channels, remove obstacles |
| -76... -85 | Bad | Connection breaks, low speed | A repeater or router replacement is required. |
| -86... -100 | Critical | There is practically no connection | Amplifiers won't help; you need to change the access point. |
Please note that for the 5 GHz band, the values may be slightly lower (worse) due to lower penetration, but the data transfer rate will be higher. The 2.4 GHz band is characterized by higher signal values, but higher noise levels.
Factors Affecting WiFi Quality
Understanding the physics of the process helps not only measure but also improve the signal. Radio waves behave unpredictably in complex urban environments. The main enemy is multipath propagation, when the signal is reflected from objects and arrives at the receiver with a delay, creating interference.
- 🧱 Walls and ceilings: Reinforced concrete and brick dampen the signal more than plasterboard or wood.
- 🌊 Water: Aquariums and even indoor plants with a lot of moisture can screen the signal.
- 📺 Household appliances: Microwave ovens operate at a frequency of 2.4 GHz and create strong interference during operation.
It's also worth considering the number of neighboring networks. If 10 routers are operating on the same channel in an apartment building, there will be a "mess," and speed will drop even with a strong signal. In such cases, switching to the 5 GHz band or using a standard can help. WiFi 6, which is better able to ignore interference.
☑️ Check-up your network
Methods of strengthening and optimization
If your measurements show unsatisfactory results, don't rush to buy new equipment. Often, the problem can be solved with proper configuration. First, try changing the broadcast channel in your router settings to a less congested one. The automatic channel selection mode ("Auto") often malfunctions and fails to switch to a free frequency.
The second step is to physically relocate the router. The ideal location is the center of the apartment, 1.5–2 meters above the floor. The antennas should be vertical. If the router has external antennas, try adjusting their angle to find a "sweet spot" for your specific device.
⚠️ Attention: Don't use homemade foil amplifiers ("biosters"). They can change the antenna pattern so that the signal in the desired room disappears completely and the router itself overheats.
If rearranging your furniture and router doesn't help, consider purchasing a mesh system. Unlike traditional repeaters, mesh networks create a seamless space by automatically switching devices to the nearest access point with the best signal.
The Antenna Booster Myth
Sticking foil onto a router's antenna is a popular life hack that often makes things worse by creating standing waves and overloading the transmitter.
Frequently Asked Questions (FAQ)
Why is the internet speed low although the signal level is high (-40 dBm)?
A high signal strength (RSSI) only indicates the transmit power, not the channel quality. The problem could be due to congestion on the frequency by neighboring devices, a low signal-to-noise ratio (SNR), or speed throttling by the ISP. It's also possible that the device is connected to the 2.4 GHz band, which has low real-world throughput.
Does the number of connected devices affect the signal strength?
No, the number of devices does not affect the physical signal strength (dBm) displayed by a router or phone. However, it does directly impact internet speed and ping, as the channel bandwidth is divided among all active clients.
Can weather affect indoor WiFi?
Weather doesn't directly affect the signal inside an apartment, as the walls protect it from external factors. However, a strong thunderstorm can create electromagnetic interference, and high humidity theoretically absorbs radio waves slightly more, although this isn't noticeable within an apartment.
Which is better for range: 2.4 GHz or 5 GHz?
For long-range coverage and wall penetration, the 2.4 GHz band is clearly superior. Waves at this frequency bend better around obstacles. The 5 GHz band offers higher speeds, but has a shorter range and is less effective at penetrating solid walls.