When faced with slow page loading or constant video stream interruptions, the first thing most users wonder about is the quality of their wireless connection. Understanding What is considered a good WiFi signal?, is key in diagnosing problems with a home or office network. We often rely solely on the number of "bars" in the corner of our smartphone screen, but this indicator doesn't provide an accurate technical picture of what's going on.
For a thorough analysis, it's necessary to rely on specific signal strength values, measured in decibel milliwatts (dBm). This data allows you to objectively assess the network's condition, identify "dead zones," and determine whether you need to replace your router or configure a repeater. In this article, we'll cover the technical details that will help you set up a stable internet connection.
Units of measurement and scale of dBm
The primary metric for wireless connection quality is the received signal strength, referred to as RSSI (Received Signal Strength Indicator). Unlike wired networks, where voltage is important, wireless technologies use a logarithmic scale. dBm (decibels relative to 1 milliwatt). The peculiarity of this scale is that the values are always negative, since the signal attenuates during transmission.
The closer the value is to zero, the stronger the signal. For example, -40 dBm is significantly better than -80 dBm. Many users mistakenly believe that a large negative number indicates a strong signal, but in reality, it indicates severe attenuation. A difference of just 3 dBm represents a twofold change in signal strength, making this metric extremely sensitive to environmental changes.
It's important to understand that achieving a perfect signal of -1 dBm in real-world conditions is virtually impossible due to the physical limitations of equipment and regulatory radiation regulations. Therefore, when assessing connection quality, we always use a range from -30 dBm to -90 dBm, with each value having its own interpretation.
Interpreting signal levels: from ideal to lost connection
To accurately determine the health of your network, you need to know the gradation of values. WiFi signal strength Internet speeds can be divided into several categories, each of which dictates its own internet usage capabilities. Understanding these thresholds will help you quickly determine whether you need to relocate your router or replace the antennas.
The range from -30 dBm to -60 dBm is considered excellent to very good. In this zone, you can expect the maximum speeds advertised by your provider and stable operation of any applications, including online gaming and 4K streaming. In these conditions, data packets are transmitted virtually without loss or retransmissions.
⚠️ Warning: Values below -85 dBm often lead to a complete connection loss. If your smartphone shows -88 dBm or lower, stable network operation is impossible, even if the indicator shows one bar.
The average signal level is considered to be between -60 dBm and -75 dBm. This range is comfortable for working with documents, browsing the web, and watching HD videos. However, when downloading large files or during peak hours, you may experience slight speed drops. A signal below -75 dBm is considered weak: video calls may drop out, and games may experience high ping.
Signal strength and connection quality correlation table
To easily organize your data, it's helpful to use a summary table. It allows you to quickly compare technical data with real-world user experience. Please note that range limits may vary slightly depending on the sensitivity of your device's receiver (smartphone, laptop, or set-top box).
| Signal level (dBm) | Signal quality | Recommended tasks | Stability |
|---|---|---|---|
| -30... -50 | Ideal | 4K/8K video, VR, online gaming | Maximum |
| -51... -65 | Very good | HD streaming, video conferencing | High |
| -66... -75 | Good | Web surfing, social media, music | Average |
| -76... -85 | Weak | Text messaging, email | Low |
| -86... -90 | Critical | Unstable connection | Almost absent |
Using this data, you can conduct an audit of your home. Walk around your apartment with your phone and record readings at various points. This will help you identify areas where WiFi coverage requires improvement. It often turns out that the signal is perfect in one room, but through one wall it drops to critical levels.
☑️ Network quality check
Factors Affecting Signal Attenuation
Even the most powerful router can't penetrate every obstacle in its path. The physics of radio wave propagation dictates its own rules, and understanding these factors will help you place your equipment correctly. Signal attenuation This occurs not only due to distance, but also due to the materials through which the wave passes.
- 🧱 Walls and ceilings: Reinforced concrete walls with rebar are a virtually impenetrable barrier to 5 GHz frequencies. Brick and wood block the signal less, but still introduce their own limitations.
- 🌊 Water: Aquariums, heating pipes, and even large houseplants can significantly weaken the signal, as water is an excellent absorber of radio waves.
- 📡 Metal surfaces: Mirrors, foil insulation, and metal cabinets reflect the signal, creating complex interference patterns.
In addition to physical obstacles, electromagnetic interference plays a significant role. Microwave ovens operating at 2.4 GHz can completely jam Wi-Fi while heating food. Neighbors' routers, Bluetooth devices, and wireless baby monitors also generate noise, reducing the signal-to-noise ratio (SNR), which directly impacts speed.
Why is 5 GHz worse at passing through walls?
The 5 GHz band uses a shorter wavelength than 2.4 GHz. Shorter wavelengths are less able to bypass obstacles and attenuate more quickly in dense materials like concrete. However, they provide significantly higher data rates over short distances.
Diagnostics and signal level measurement
To obtain accurate data, looking at the standard operating system indicator isn't enough. You need specialized tools that will show the real picture. Built-in OS tools often hide details, showing only average values.
On Windows computers, you can use the command line. Open Terminal and enter the command netsh wlan show interfacesIn the list that appears, find the "Signal" line, which will display the power percentage. To convert to dBm, you'll need a calculator or a conversion table, as Windows displays percentages by default.
netsh wlan show interfacesMore advanced users and Android smartphone owners are advised to use analyzer applications such as WiFi Analyzer or Fritz!App WLANThey display a real-time graph, showing not only your signal strength but also the channel congestion of your neighbors. This allows you to select the least noisy channel for router configuration.
⚠️ Note: When using third-party apps on iOS, functionality may be limited by Apple's security system. For accurate measurements on iPhone, it's best to use the built-in test field in Settings or Mac address scanners.
Methods of coating enhancement and optimization
If your measurements show unsatisfactory results, don't rush into buying new equipment. Often, the problem can be solved with proper rearrangement or adjustment. Optimizing your WiFi network It starts with proper placement of the access point.
- 📍 Centering: Place the router in the geometric center of your apartment or office, preferably at a height of 1.5–2 meters from the floor.
- 📶 Antennas: If your router has external antennas, point them perpendicular to each other (one vertically, one horizontally) to cover different receiver polarizations.
- 🔄 Ranges: Use the 2.4 GHz band for distant rooms and older devices, and reserve 5 GHz for TVs and laptops located near the router.
In cases where relocation doesn't help, it's worth considering expanding the network. Repeaters can receive the signal and transmit it further, albeit at a loss of speed. A more modern solution is Mesh systems, which create a single seamless space with automatic switching of devices between nodes.
The Impact of WiFi Standards on Range and Speed
It's important to remember that a "good" signal is a relative concept and depends on the communication standard. Older devices that use the protocol 802.11n, can show stable operation at a level of -75 dBm, while modern standards WiFi 6 (802.11ax) require cleaner air to realize their high-speed potential.
New standards use more complex modulation schemes (such as 1024-QAM), which are sensitive to noise. Therefore, at the edge of the coverage area, the router may automatically reduce the connection speed to a more stable standard, even if the "bars" on the phone screen indicate full bandwidth. This is normal behavior, ensuring uninterrupted connection.
When planning your network, keep in mind that the building density in your area may dictate the use of certain frequencies. In apartment buildings, 2.4 GHz airwaves are often oversaturated, and the only solution is switching to 5 GHz or using directional antennas.
Why does the speed drop as I move further away from the router, even if there is a signal?
The speed decreases due to the adaptive modulation mechanism. When the signal strength declines or the error rate increases, the router and client device switch to simpler, more noise-resistant data encoding methods. This reduces the speed but maintains a stable connection.
Can weather affect indoor WiFi?
Weather doesn't have a direct impact, as the walls protect against external factors. However, high humidity (fog, heavy rain) could theoretically slightly increase signal attenuation if it passes through open windows or uninsulated structures, but under normal conditions, this effect is negligible.
What signal is needed for HD video calls?
For stable HD video calls (720p and above), a signal level of at least -65 dBm is recommended. Signal levels below -70 dBm may result in artifacts, audio delays, and reduced image resolution.