How to change Wi-Fi power on a MikroTik: tx-power settings

Managing the radio frequency spectrum in corporate and home networks requires precise equipment calibration, and configuring MikroTik devices to change Wi-Fi power is a key administrator skill. Users often encounter a paradoxical situation: the higher the transmitter power is set, the worse the wireless network performs. This occurs due to signal asymmetry, where the client device "speaks" loudly enough for the router to hear, but is unable to "hear" the return signal due to the limitations of its antenna.

Correct setting tx-power (transmission power) not only expands coverage but also significantly reduces interference between neighboring access points. The RouterOS ecosystem offers flexible radio parameter management, allowing for individual output power adjustments for each interface, which is critical when building dense networks with a large number of access points.

Before making any changes, it's important to understand that maximum power doesn't always equal maximum performance. Excessive signal can clog the airwaves, creating high levels of noise and interfering with other devices in the 2.4 GHz or 5 GHz band. A competent engineer always begins with an analysis of the radio environment and only then selects the optimal emission level, balancing coverage and connection quality.

Anatomy of a wireless signal and hardware limitations

The physics of the process dictates its own strict rules: wireless communication is a two-way process. When you increase the transmitter power on your router MikroTikBy increasing the range of the router, you expand the range at which clients can hear the router, but you don't increase the range at which clients can hear the router. Smartphones and laptops have built-in low-gain antennas and limited output power, typically not exceeding 100 mW (20 dBm).

Setting the access point's power to 1000 mW (30 dBm) will create a "dead phone" effect. The client device will see the network and even attempt to connect, but acknowledgement (ACK) packets from the router will arrive at a signal strength below the client's receiver sensitivity threshold. As a result, the connection speed will drop to a minimum, and the number of retries (packet retransmissions) will increase exponentially.

Furthermore, there are legislative restrictions. In the Russian Federation and most CIS countries, there are standards governing the maximum equivalent radiated power (EIRP). Exceeding these standards can result in fines from the regulator (RKN) and interference with critical services.

⚠️ Attention: Using illegal drivers or modified firmware to remove power restrictions is a violation of radio spectrum laws. Always check the current regulations in your region before setting higher than standard values.

Modern chipsets used in MikroTik, have Country tables that automatically limit available power based on the selected region. This is a safety mechanism to prevent accidental violations of laws. However, even within the permitted limits, a "sweet spot" can be found for stable operation.

WinBox interface: navigating to radio settings

For making changes to the wireless module's configuration, the most convenient tool remains the WinBox utility. It provides graphical access to all hidden parameters that aren't always obvious in the web interface. The first step is to log in to the device and go to the section Wireless.

In the window that opens, you'll see a list of all wireless interfaces. For dual-band routers, such as MikroTik hAP ac² or cAP ac, two interfaces will be displayed here: one for 2.4 GHz (usually wlan1) and one for 5 GHz (wlan2). Double-clicking on the desired interface will open the settings window, where we are interested in the tab Wireless and a button Advanced Mode in the upper right corner.

Without enabling the advanced settings mode (Advanced Mode) Many critical parameters, including detailed power settings, remain hidden. Once this mode is activated, a full parameter table becomes available, allowing you to manipulate frequencies, channel width, and, of course, transmit power.

Please note that some equipment models, especially series hEX or RB without built-in Wi-Fi, require connection of external expansion cards (for example, R11e-2nD or R11e-5HnD). Power settings for integrated modules and external mini-PCIe cards may vary in the range of available values.

Setting up TX-Power: Step-by-Step Instructions

Direct power control is achieved via the parameter tx-powerIn the wireless interface settings window, in the mode Advanced Mode, find the field tx-powerBy default, there may be a value there default or a specific number in dBm. This is where the magic of radio wave control happens.

Power is measured on a logarithmic scale of decibels to milliwatts (dBm). Understanding this scale is essential for proper tuning. Every 3 dBm increase doubles the radiated power, and every 10 dBm increase increases the power tenfold. For example, 20 dBm is 100 mW, 23 dBm is approximately 200 mW, and 30 dBm is 1000 mW (1 W).

/interface wireless set wlan1 tx-power=17

This command entered in the terminal (New Terminal), sets the WLAN1 interface power to 17 dBm (approximately 50 mW). This is often the optimal value for small apartments or office spaces where access points are located close to each other. For larger warehouses or open spaces, the value can be increased to 23-26 dBm, depending on regulations and antenna design.

If you are setting up the main access point that you are currently connected to, make sure you have a wired connection or access via another interface to avoid losing control of the device.

What is EIRP and why is it important?

EIRP (Equivalent Isotropically Radiated Power) is the total effective radiated power. It is calculated as the sum of the transmitter power (TX power) and the antenna gain, minus cable loss. Legislation limits EIRP, not just transmitter power. If you have an antenna with a gain of 10 dBi, your transmitter power must be lower than for an antenna with a gain of 2 dBi. When calculating the total power, always take your antenna gain into account. Using a powerful transmitter with a high-gain antenna may result in exceeding legal limits.

Power and usage scenarios correspondence table

Selecting the correct power level depends on many factors: the type of building, wall materials, the presence of neighboring networks, and the type of client devices. Below is a table to help you understand approximate values ​​for various operating conditions.

The data in the table is for guidance only. Real-world conditions may dictate adjustments. For example, in an old building with thick concrete walls, even 23 dBm may not provide reliable reception in a distant room, while in a wooden house, 14 dBm will penetrate three floors.

Power management via terminal (CLI)

For experienced administrators or when automating processes through scripts, command-line configuration (CLI) is preferred. The MikroTik terminal allows for quick configuration changes across multiple devices or the application of complex logic.

To view the current power settings, use the command:

/interface wireless print

In the command output, look for the column tx-power. If it is indicated there default, then the automatic or country settings are working. To force the value, use the command set specifying the interface name.

It's also possible to configure dynamic power adjustments based on time of day or channel load, although standard RouterOS tools implement this through complex scripts. Most often, power is fixed statically after testing.

⚠️ Attention: When working via the CLI, pay close attention to the syntax. An error in the command can lead to the wireless interface being disabled or, in rare cases, loss of access to the device if you change the wireless access settings.

To reset the power settings to factory defaults (mode default) you can use the command:

/interface wireless set [find] tx-power=default

This will return power management to the algorithms built into the Country profile, which is often the best solution for inexperienced users.

Problems and Solutions: Why Wi-Fi Isn't Working

After changing settings, users may encounter unexpected issues. One of the most common is devices losing network visibility or being unable to connect, even though they were previously working reliably. This is a classic sign of power outages, as discussed at the beginning of this article.

Another common problem is speed "jumping." The client constantly switches between standards (for example, from 802.11n to 802.11g) or changes channel width. This can be caused by interference, amplified by high transmitter power, which "clouds" the desired signal with noise.

It is also worth checking the thermal conditions of the equipment. Operation at maximum power (maximum tx-power) leads to increased heat generation. If the router MikroTik If the unit does not have active cooling or is installed in a closed panel, it may throttle (reduce performance) or reboot due to overheating of the processor or radio module.

If you experience instability, try reducing the power by 3-5 dBm. This often paradoxically improves connection speed and stability, eliminating unnecessary reflections and echoes in the room.

How do I reset my Wi-Fi settings if I lose access?

If you lose access to your Wi-Fi network after changing settings, the only way to restore control is to use an Ethernet cable (LAN port) or perform a hard reset using the reset button on the case. To reset using the reset button, hold it down while turning on the power until the ACT indicator flashes, but remember that this will erase all settings, not just the wireless ones.

Does the tx-power setting affect internet speed?

Directly, no; speed depends on your provider's plan. Indirectly, yes. Incorrect power consumption causes packet loss and retries, which reduces actual throughput and increases ping, creating the illusion of a slow internet connection.

Is it possible to increase the power above the factory one?

Technically, in some countries and on some models this is possible by changing the Country settings or using special modes, but this is illegal and can lead to the radio module burning out due to exceeding the design loads.