When a provider promises a "hundred" of data at the start, users often expect to see the same numbers on their smartphone screen, but reality makes its own adjustments. Wireless environment Data transmission imposes inevitable limitations, which depend on numerous technical factors. Under ideal laboratory conditions, digital performance may match the stated figures, but in a residential apartment or office with concrete walls and neighboring routers, the picture changes.
The physics of the process is such that radio channel Never operates at 100% efficiency; some bandwidth is consumed by overhead and error correction. Therefore, if you see 80-90 Mbps instead of 100 Mbps on a speed test, this is completely normal for high-quality equipment. You should start to panic if the readings drop below 40-50 Mbps, which indicates configuration issues or interference.
In this article, we'll take a detailed look at why losses occur, how frequency range affects them, and what you can do to maximize speed. Understanding these processes will help you distinguish between a provider issue and your own specific operating conditions. router.
Physical limitations of the wireless channel
The main reason for the discrepancy between the tariff and the actual speed lies in the data exchange protocols. Wi-Fi Half-duplex technology means a device cannot simultaneously receive and transmit data on the same frequency without losing efficiency. Each packet of information requires a delivery receipt, which creates traffic overhead that's invisible to the naked eye but noticeable in real-world terms.
Furthermore, the signal is susceptible to attenuation when passing through obstacles. Even a drywall partition or a mirror can reduce the signal strength, forcing the router to switch to a more stable but slower encoding method. Modulation changes dynamically: the worse the connection, the lower the speed in order to maintain a stable connection.
It is important to understand that theoretical maximum The 802.11n or 802.11ac standards are almost never achieved in practice due to these physical limitations. Actual throughput is typically 50-70% of the link speed specified in the specifications.
Impact of 2.4 GHz and 5 GHz bands on speed
Modern routers operate in two main frequency ranges, and the choice between them critically affects the final result with a 100 Mbps tariff. Range 2.4 GHz It's the most common, but also the most cluttered. In apartment buildings, dozens of networks can operate here, creating interference and causing speeds to drop to 20-30 Mbps even with a strong signal.
Range 5 GHz Offers significantly higher bandwidth and is less susceptible to interference from household appliances like microwaves. On this frequency range, with a 100 Mbps plan, you can get real speeds of 85-95 Mbps, which is almost equal to a wired connection. However, it does have a drawback: shorter range and poorer wall penetration.
If your smartphone or laptop supports the standard 802.11ac or 802.11ax, it is highly recommended to switch to the 5 GHz network for resource-intensive tasks. This is especially true for watching 4K video, online gaming, and video calls, where not only speed but also ping stability are important.
Real-World Speed Performance: Comparison Table
To help you navigate the numbers, we've compiled a table showing the expected speed under various connection conditions. These figures are averages and depend on the quality of the client device (smartphone or laptop).
| Connection conditions | Range | Expected speed (Mbps) | Comment |
|---|---|---|---|
| Direct connection (cable) | N/A | 94-98 | Reference value |
| The router is nearby (1-2 meters) | 5 GHz | 80-95 | Maximum efficiency |
| The router is in the next room | 5 GHz | 50-70 | One wall reduces the signal |
| Congested airwaves (many neighbors) | 2.4 GHz | 15-35 | High level of interference |
As the table shows, even under good conditions, a wireless network can consume around 5-10% of the speed. This is a technical issue, not a hardware defect. If you're two rooms away from the router and using the older 2.4 GHz band, your speed can drop threefold.
Factors that reduce Wi-Fi speed
There are a number of reasons why your speed may be slower than expected. Users often forget that connection speed is determined by the slowest part of the chain. If you have a 100 Mbps plan but your router is older and only supports the standard 802.11n with one antenna, it physically won’t deliver more than 40-50 Mbps.
It's also worth considering the number of connected devices. When one user is downloading torrents, another is watching YouTube in 4K, and a third is gaming online, the bandwidth is split between everyone. Channel becomes overcrowded and each device receives only a fraction of the available speed.
⚠️ Attention: Outdated network card drivers on your laptop can limit speed even with a modern router. Check your laptop manufacturer's website and update your Wi-Fi adapter drivers.
Another factor is the wall material. Reinforced concrete, metal structures, and large mirrors with amalgam coatings act as a shield, blocking the radio signal. In such cases, even a powerful router won't be able to provide high speeds in a distant room.
Why does the speed fluctuate?
Speed may fluctuate due to the router dynamically switching channels in an attempt to find a less noisy frequency. This is also affected by nearby Bluetooth devices, as they operate in the same 2.4 GHz band.
How to check and diagnose speed
To obtain reliable data, it's important to conduct measurements correctly. Simply running a test in a browser isn't enough, as the browser itself or background processes can affect the results. It's best to use specialized services, such as Speedtest.net or Fast.com.
To eliminate interference from other devices, we recommend disconnecting all devices except the one being tested from Wi-Fi before testing. Also, ensure that no system updates or cloud photo syncing are running in the background.
☑️ Speed test
Run a series of 3-5 tests at different times of day. If the speed drops significantly more in the evening, when your neighbors are actively using the internet, than during the day, the problem is band congestion. In this case, manually changing the channel in the router settings will help.
Optimizing your router settings for maximum performance
To get the most out of your 100 Mbps plan, go to your router's control panel. The address is usually available at 192.168.0.1 or 192.168.1.1. In the wireless network section (Wireless Settings) Make sure the channel width for the 5 GHz band is set to 40 or 80 MHz. For 2.4 GHz, the channel width must be strictly 20 MHz, otherwise, in noisy environments, the speed will only drop due to errors.
Check your wireless network mode. If it's set to "N Only" or "AC Only," older devices may not connect, but the speed will be more stable. "Mixed" mode ensures compatibility but may slightly reduce overall network performance.
⚠️ Attention: Changing the 2.4 GHz channel width settings from 20 to 40 MHz in an apartment building often has the opposite effect—speed drops due to overlap with neighboring channels.
Don't forget to update your router's firmware. Manufacturers regularly release updates that improve the stability of the radio module and fix bugs that affect data transfer speeds.
When is it time to change equipment?
If your speed remains low after adjusting all the settings, your router may simply be outdated. Devices manufactured more than 5-7 years ago often have weak processors that can't handle traffic encryption at high speeds. Signs that your router isn't up to par include high latency (ping) and connection drops during heavy downloads.
When choosing new equipment, pay attention to the standard support Wi-Fi 6 (802.11ax)Even if your current devices don't support it, it will provide future-proof performance and better performance across multiple connected devices.
Mesh systems are also worth considering if you have a large apartment. A single powerful router might not be able to penetrate three load-bearing walls, but a system with several modules will ensure stable speeds in every room.
Why is the Wi-Fi speed only 20 Mbps with a 100 Mbps plan?
You're most likely connected to the 2.4 GHz band in a noisy environment, or you're located far from the router behind several walls. It's also possible that your smartphone or laptop only has one Wi-Fi antenna, limiting your maximum connection speed.
Does the number of connected devices affect the speed of one client?
Yes, it does. Wi-Fi is a shared medium. If one device is actively downloading files, it takes up airtime, and other devices have to wait their turn to transmit packets, reducing the overall available speed for everyone.
Do I need to change my router if my provider increases my internet rate to 200 Mbps?
Most likely, yes. Older 802.11n routers physically can't transmit more than 50-60 Mbps over the air. For plans above 100 Mbps, you need a router that supports 5 GHz and the 802.11ac (Wi-Fi 5) standard or newer.