Modern wireless networks face enormous radio spectrum congestion, especially in apartment buildings where a single stairwell may contain more than ten active access points. Signal interference From neighboring routers, interference leads to speed drops, increased ping, and occasional connection drops, making proper frequency planning a critical step. Properly configuring WiFi channels on your equipment MikroTik allows not only to avoid conflicts, but also to significantly increase the throughput of the local network.
Unlike consumer solutions, where algorithms often operate automatically and not always effectively, MikroTik routers provide the administrator with complete control over radio resources. Using a 20 MHz channel width in the 2.4 GHz band is the only way to ensure no overlap with neighboring networks in densely populated areas.Understanding the physical principles of radio wave propagation and the specifics of the 802.11ac/ax standards is essential for building a stable infrastructure.
In this guide, we'll cover the process of analyzing the airwaves, selecting optimal frequencies, and fine-tuning wireless interface parameters. You'll learn how to use built-in monitoring tools and avoid common mistakes that can negate the benefits of expensive equipment. Proper configuration is a balance between coverage and speed.
Radio broadcast analysis and frequency selection
The first and most important step before making any configuration changes is a thorough analysis of the surrounding RF environment. The built-in tool in RouterOS Wireless has a powerful scanner that allows you to see all available networks, their signal level (signal strength) and the channels used. Start scanning through the menu. Wireless -> Interfaces -> [your interface] -> Scanto get an up-to-date picture of spectrum congestion.
When analyzing the scan results, pay attention not only to the number of networks but also to their strength. A distant router with a weak signal (-85 dBm) will pose fewer problems than a neighboring device behind a wall with a signal strength of -55 dBm. Crossing of channels This results in devices being forced to wait for the transmission medium to become available, which dramatically reduces the actual data exchange rate even at a high signal level.
⚠️ Attention: RouterOS interfaces and menu layouts may vary depending on the operating system version (v6, v7) and the installed card type (hAP, SXT, LHG). Always consult the manufacturer's official documentation for your specific hardware model.
The 2.4 GHz band has only three non-overlapping channels: 1, 6, and 11. If you live in a high-rise building, one of these channels may be completely occupied, forcing you to choose the "lesser of two evils" by selecting the channel with the least interference. The 5 GHz band is better off, as it offers many non-overlapping frequencies, making it easy to find a clear section of spectrum.
Setting up channel width and standards
Channel width (channel width) directly affects the maximum theoretical data transfer rate, but also determines the noise level and the likelihood of collisions. In the 2.4 GHz band, using a 40 MHz bandwidth is almost always a mistake, as it covers almost the entire available range and is guaranteed to create collisions with neighbors. The optimal and often only reasonable choice here is 20MHz.
In the 5 GHz band, the administrator has more freedom of action. Here, the width can be safely used 40MHz, 80MHz and even 160MHz (If the hardware and WiFi 6 standard allow it). However, keep in mind that the wider the channel, the higher the risk of interference from radar or other powerful sources, which will lead to temporary frequency switching.
When selecting a wireless communication standard (wireless-protocol) it is recommended to use 802.11ac or 802.11ax for modern devices, disabling legacy modes 802.11b/gThis will not only improve overall network performance, but also free up airtime that would otherwise be wasted serving slow clients. Configuration is performed in the section Wireless -> Security Profiles and directly in the interface properties.
It's important to note that some clients may not work correctly with a certain channel width, even if they support the advertised standard. If you experience connection instability on a specific device, try forcibly reducing the channel width in the access point settings. This will reduce peak speed but improve link stability.
Adjusting the transmitter power
A common misconception is to set the transmitter power to maximum (tx-power) at all access points. High power doesn't always mean a better signal; it often leads to increased noise and "clogged" airwaves, interfering with other devices. Optimal power is determined experimentally and depends on the building density and coverage requirements.
In an apartment or small office, the value is often sufficient 17-20 dBm (approximately 50-100 mW). This setting allows the client device (to "hear" the access point) and the access point itself (to "hear" the client) to operate in balance. If the access point's power is too high, the phone may show a full signal strength but be unable to transmit data due to the low power of its transmitter.
The setting is done in the menu Wireless -> Interfaces -> [your interface], in the field tx-powerHere you can also select the mode auto, however, manual mode is preferable for fixed points, as it ensures predictable network behavior. For outdoor solutions, such as MikroTik SXT or LHG, the power may be higher, but the principle "the more the better" does not work here either.
☑️ Checking WiFi settings
Reducing power also helps ensure efficient roaming in networks with multiple access points. The client device will quickly "let go" of a moving access point and switch to a nearby one if the signal strength from the current one begins to drop earlier. This prevents the "sticky client" phenomenon, where the smartphone clings to a distant tower until the very end.
Table of recommended parameters for different scenarios
To simplify the setup process, we've provided a summary table with recommended parameter values for various operating conditions. These settings are basic and may require adjustment depending on the specifics of your room and environment.
| Use case scenario | Range | Channel width | Recommended power | Priority |
|---|---|---|---|---|
| Dense development (apartment building) | 2.4 GHz | 20 MHz | 15-18 dBm | Stability |
| Private House / Office | 5 GHz | 40-80 MHz | 20-23 dBm | Speed |
| Point-to-Point | 5 GHz | 20-40 MHz | Max. allowable | Range |
| Guest network (cafe) | 2.4 GHz | 20 MHz | 17-20 dBm | Compatibility |
When selecting parameters for the "Outdoor Point" scenario, it's important to consider your country's legal limits on open-air power. Exceeding these limits may result in fines from regulatory authorities. Always check the certification data for your equipment.
In the "Guest Network" scenario, compatibility with the maximum number of devices is a priority, so using a narrow bandwidth and supporting older standards is justified, even at the expense of speed. The most important thing for a guest is the ability to connect and send messages in a messenger.
Advanced: DFS channels and dynamic switching
In the 5 GHz range there are so-called DFS (Dynamic Frequency Selection) channels, which are also used by weather radars and military facilities. The use of these channels (52-64, 100-144) allows you to significantly expand the available space and avoid conflicts with neighbors, but imposes certain obligations on the equipment.
When selecting a DFS channel, the MikroTik access point is required to listen for radar signals for 60 seconds. Only after confirming the frequency is clear does it begin broadcasting. If a radar is detected during operation, the access point is required to immediately (within 10 seconds) stop broadcasting and switch to another channel.
⚠️ Attention: Using DFS channels can lead to brief connection interruptions during overflights or when a nearby radar is in use. This may be unacceptable for mission-critical services (VoIP, video conferencing).
List of DFS channels in different regions
In Europe (EU), channels 52-64 and 100-144 are available. In the US (FCC), the list may differ. In Russia, the rules for using DFS channels are strictly regulated and require radio electronic registration for high-power equipment, although consumer routers often operate under exceptional conditions.
To activate DFS channels in MikroTik, you need to select the appropriate frequency or mode in the wireless interface settings. superchannel (if supported by the controller). Also make sure that in the field country The correct locale is set, as the available frequency list depends on it.
Monitoring and troubleshooting
After making changes, you need to ensure that the network is stable. Use built-in monitoring tools, such as Torch or Wireless -> Registration Table, to monitor the signal strength of connected clients and the number of retransmissions. High retransmission level (tx/retry ratio) indicates poor signal quality or interference.
If you experience intermittent speed drops, try using the function Scan Repeatedly at different times of the day. Airtime can fluctuate significantly: in the evening, when neighbors return home and turn on their TVs, the noise level increases. Dynamic adjustments to the settings may be necessary.
For in-depth diagnostics, you can enable wireless interface logging. This will allow you to see system messages about channel switches, client disconnections, or authentication errors. Logs are located in the menu. System -> Log, filter them by topic wireless.
Frequently Asked Questions (FAQ)
Why doesn't my phone see the 5GHz network after setup?
Make sure you haven't selected a channel that your device's network card doesn't support (for example, some older cards don't support channels above 140). Also, check if the operating mode is set to Standard Only. 802.11ac, if the device only supports 802.11n.
Is it possible to use the same channel for 2.4 and 5 GHz?
Physically, the frequencies are different, so a channel number (for example, 36) can overlap across different bands without conflict. However, in the MikroTik interface, you select a specific frequency in MHz, not just a number. The key is to avoid overlaps within a single band.
How often should I change WiFi channels?
In a static environment (office, home), a single configuration after analysis is sufficient. In a dynamic environment (exhibition center, shopping mall), it is recommended to use automatic channel selection protocols or scripts that change settings at night.
Does 20 MHz channel width affect internet speed?
Yes, the theoretical maximum speed will be lower than on 40 or 80 MHz. However, in noisy environments, the actual speed on a narrow channel is often higher, as there is no packet loss or constant reconnection.