Selecting the correct WiFi frequency on MikroTik equipment is the foundation upon which the stability of the entire wireless network is built. Unlike simple home routers, where settings are often hidden or automated, RouterOS Gives the administrator complete control over the radio module. This allows for fine-tuning of coverage, but requires an understanding of the physical principles of radio wave propagation.
In today's dense urban environments, the airwaves are oversaturated with signals. Incorrectly selected frequency or channel width leads to slow speeds and constant connection drops. You need to consider not only the technical specifications of your equipment but also the surrounding RF environment.
In this article we will look at how to correctly select the range, set up scan-list and avoid typical errors when configuring interfaces wlan1 And wlan2 on MikroTik devices. Proper configuration will ensure maximum throughput and minimize interference.
Differences between the 2.4 GHz and 5 GHz bands
The first decision an administrator makes is choosing an operating band. On MikroTik, this is a basic setting in the Wireless tab. 2.4 GHz It has better penetration through walls and covers a larger area, but it is extremely overloaded with neighboring networks and household appliances.
⚠️ Please note: Using the 2.4 GHz band in multi-family buildings often leads to collisions due to the limited number of non-overlapping channels.
Range 5 GHz Provides significantly higher data transfer rates and has more available channels. However, the signal at this frequency has poorer penetration through concrete floors and fades more quickly over distance. Modern MikroTik models, such as hAP ac or cAP ac, support operation in both ranges simultaneously.
When choosing a frequency, it is important to understand that Wireless Protocols operate in half-duplex mode. This means a device cannot transmit and receive data simultaneously on the same frequency. The higher the frequency, the shorter the wavelength, which affects the physics of signal propagation in your room.
Setting Channel Width
Channel width is a critical parameter that determines throughput and noise levels. In the MikroTik interface, it is denoted as channel-widthStandard values include 20 MHz, 40 MHz, 80 MHz, and even 160 MHz for the WiFi 6 standard.
Increasing the channel width allows for more data to be transmitted per unit of time, but it also increases the radio card's appetite for clear air. If you set the channel to 40 MHz or 80 MHz in a noisy environment, you'll pick up more interference, leading to packet retransmission and a drop in actual speed.
For the 2.4 GHz band It is recommended to use a channel width of strictly 20 MHzTrying to use 40 MHz in this range in urban conditions is almost guaranteed to result in unstable operation, as you will cover almost all the available spectrum.
In RouterOS, the configuration is done in the menu WirelessWhen selecting a value 20/40mhz-Ce or 20/40/80mhz-Ceee The router will attempt to aggregate channels if they are free. If the airtime is busy, it will fall back to the base bandwidth, but this may cause delays.
Ether analysis and frequency selection
Before locking on a frequency, you need to conduct a reconnaissance of the area. MikroTik provides a powerful tool for scanning the surrounding area. Go to the menu Wireless, select the desired interface and click the button Scan.
The window that opens will display a list of all visible access points with their frequency (frequency), signal level (signal strength) and congestion. Look for "windows"—frequencies where the number of neighbors is minimal and their signal strength is weaker than -85 dBm.
| Parameter | Description | Recommendation |
|---|---|---|
| Signal Strength | Neighbors' signal strength | Avoid channels with a signal stronger than -75 dBm |
| CCQ | Client Connection Quality | Target value above 80% |
| Tx/Rx Rate | Connection speed | Depends on the channel width |
| Uptime | Neighbor's working hours | It's better not to touch stable networks. |
After analysis, select a free frequency manually by setting the parameter frequency in the interface settings. Automatic selection (frequency-mode) is not always effective, since the algorithm may select a channel with a short-term absence of noise, which will quickly fill up.
☑️ Check before fixing the frequency
For example, the device may not see channels above 165 in the 5 GHz band or specific frequencies in the DFS band.
Using DFS channels
The 5 GHz band contains so-called DFS (Dynamic Frequency Selection) channels. They are designed for use with meteorological and aviation radars. MikroTik can operate with them, but with certain limitations.
When turning on an access point on a DFS channel (e.g., 5260 MHz - 5700 MHz), the router must first listen for 60 seconds (CAC - Channel Availability Check). Only after confirming the absence of a radar signal will it begin broadcasting Wi-Fi.
⚠️ Warning: If the router detects a radar signal on the selected frequency during operation, it must immediately stop transmitting and switch to another channel, which will cause a connection break for all clients.
Using DFS channels is a great way to reduce noise in an apartment building where the primary channels (36-48) are fully occupied. However, this introduces a delay when rebooting equipment and the potential risk of frequency switching.
Setting up DFS in MikroTik usually requires no additional steps other than selecting the appropriate frequency. The system will automatically detect the channel type. You can use the logs to check the status (Log), where there will be records of radars (radar detected).
What is Country Set?
A Country Set is a set of rules that determines the permitted frequencies and maximum power for a specific country. Changing this setting can either unlock additional channels or block them according to legal requirements.
Setting up Scan-List and priorities
Parameter scan-list In MikroTik, this determines which frequencies the router will check when searching for networks (in client or WDS mode) or when scanning the surrounding area. By default, it uses the standard frequency set for the selected region.
Optimization scan-list This speeds up client reconnection and network discovery. If you know for sure that your building only uses the 5500 MHz frequency, there's no point in forcing the radio card to scan the entire range.
To edit the frequency list, use a comma-separated format or dashes for ranges, for example: 2412,2437,2462 or 5180-5240This is especially true for scenarios. Wireless ISP, where the links are tuned to fixed frequencies.
In modern versions of RouterOS (v7), frequency management has become even more flexible. You can create installation profiles (installation) with specific frequency sets, which is convenient for mass deployment of equipment.
Impact of Country Settings on Available Frequencies
Parameter country In the wireless network settings, it doesn't just change the flag on the logo. It strictly regulates the list of available frequencies and the maximum transmission power (tx-power), permitted by the legislation of the selected country.
When changing the country, the list of available frequencies is in the field frequency may change. For example, in some regions, certain channels in the 5 GHz band are prohibited, or the transmit power is limited to 20 dBm.
It is not recommended to select "no_country_set" or "supercountry" unless you understand the consequences. This may result in operating on prohibited frequencies, which could interfere with security services or nearby equipment and lead to regulatory fines.
You can check the current limits in the MikroTik documentation for your specific card model. Some cards have hardware limitations that prevent them from exceeding certain power levels, even when changing regions.
Frequently Asked Questions (FAQ)
Why can't my MikroTik see the 5 GHz network?
Check your settings country — this frequency may be prohibited in your region. Also, make sure the channel width isn't set to a value unsupported by the client device, and that the card physically supports 5 GHz (dual-band).
What is the maximum speed you can get on 2.4GHz?
In real-world conditions, with a 20 MHz channel width and the 802.11n standard, actual speeds rarely exceed 40-50 Mbps due to protocol overhead and interference. The theoretical maximum is significantly higher, but unattainable in noisy environments.
Is it possible to combine 2.4 and 5 GHz into one network with one name?
Yes, this is called SSID roaming, or simply sharing the same SSID. However, MikroTik doesn't automatically switch clients between frequencies (band steering) at the driver level as effectively as proprietary systems. The client decides when to switch, which often leads to "stuck" on 2.4 GHz.
What to do if all channels are busy?
Use a spectrum analyzer (either built-in or a separate one) to find the least crowded channel. There's almost always a clear spot in the 5 GHz band. For 2.4 GHz, try reducing your transmitter power to reduce your range and avoid conflicts with distant neighbors.