How to increase the coverage area of ​​a MikroTik Wi-Fi network

The problem of "dead zones" in wireless networks is familiar to many MikroTik equipment users. Often, the standard range of built-in antennas is insufficient to cover an entire home or office, especially if the walls are made of concrete or contain reinforced concrete. Owners of powerful routers face a paradox: the device can penetrate a signal 100 meters, but it barely reaches the next room.

The solution lies not only in choosing a more expensive model, but also in properly configuring RouterOS software features. Properly configuring chains, adjusting transmit power, and using additional access points can transform a weak network into a reliable infrastructure. It's important to understand that increasing range is always a balance between transmitter power and receiver sensitivity.

In this article, we'll explore proven methods for expanding coverage, from basic setup to building complex mesh systems. You'll learn how to harness the hidden potential of your equipment and the most common mistakes people make when trying to boost a signal. A thorough understanding of radio wave physics will help you design a network that will operate reliably anywhere in the room.

Diagnostics of the current signal level and interference

Before making any configuration changes, conduct a thorough audit of the existing network. Blindly increasing transmitter power often leads to the opposite effect: clients will "see" the router, but their response packets will be lost due to the low sensitivity of the client devices. Use MikroTik's built-in tools for radio wave analysis.

First, use the utility Wireless > Interfaces > [your interface] > ScanThis tool will show all available networks within range and their signal strength. Pay attention not only to your own networks but also to neighboring ones that may be interfering on the same channel.

Pay special attention to the Noise Floor parameter. If it's too high, even a strong signal will be drowned out by interference. The system logs may show information about packet retries, which is a direct indicator of connection quality issues. Analyzing this data will help you choose the optimal frequency and channel width.

⚠️ Attention: When analyzing the signal, keep in mind that client devices (smartphones, tablets) have much less powerful antennas than the router. Increasing the MikroTik's power without taking the client's capabilities into account will create an asymmetrical connection, with internet access only working in one direction.

There are several key metrics to look at when troubleshooting. The table below will help you interpret the dBm values ​​and understand the health of your network.

Optimizing wireless interface settings

The first step to improving coverage should be fine-tuning the wireless interface settings in RouterOS. The default factory settings often don't take into account the specifics of your environment. Start by selecting the correct channel width: for the 2.4 GHz band, the optimal choice in noisy environments is 20MHz, not 40 MHz.

Increasing the channel width does increase theoretical speed, but it reduces receiver sensitivity and increases noise levels. If you're aiming for long-range performance, narrowing the channel will provide a more stable connection at the extreme end of the range. It's also worth experimenting with this parameter. installation, setting the value indoor or outdoor depending on operating conditions.

No less important is the parameter distance in the wireless interface settings. By default, it may be set to auto, but in challenging conditions, it's better to set it manually based on the actual distance to the farthest client. This will prevent premature connection termination due to ACK timeouts.

Managing data transfer rates (Basic Rates) is an important aspect. Disabling low rates (e.g., 1, 2, 5.5 Mbps) will cause clients to drop out sooner, but those who remain connected will have a more stable connection. However, for maximum coverage, it's best to leave the minimum rates enabled so devices can connect to the router even with a very weak signal.

Setting up Tx Power and Chains

Many users make the mistake of turning up the transmission power (tx-power) to maximum (often 30 dBm or 100 mW). This isn't always effective. MikroTik antennas have a specific gain, and the total power (EIRP) must not exceed legally established limits, usually 20 dBi or 100 mW depending on the region.

A more effective method is to properly configure the circuits. In multiple-antenna (MIMO) interfaces, each circuit can be controlled separately. Make sure that the settings chain0, chain1 and all available antennas are activated. Disabling one of the circuits reduces overall throughput and signal stability.

For fine-tuning, use the terminal. This command allows you to set different power levels for different transfer rates (MCS index). For example, you can reduce the power level for high speeds to prevent clients from trying to connect at the limit, which would result in unstable connections.

/interface wireless set wlan1 tx-power=20 tx-power-mode=all-rates-fixed

It is worth remembering that Tx Power — that's only half the equation. Receiver sensitivity also depends on the quality of the antennas and the absence of loss in the cables. If you use external antennas, make sure you use low-attenuation cable (such as LMR-400), especially if the cables are longer than 1 meter.

⚠️ Attention: Exceeding the Equivalent Radiated Power (EIRP) limit may result in fines from telecommunications regulators and may cause interference to other equipment. Always verify your settings with the laws and regulations in your country.

Using external antennas and amplifiers

When software methods aren't enough, hardware can help. Replacing the stock antennas with more powerful directional or omnidirectional high-gain antennas is the most direct way to increase coverage. MikroTik routers are compatible with antennas with RP-SMA or N-type connectors, depending on the router model.

Directional antennas (sector or panel antennas) allow you to "punch" a signal in a specific direction, ignoring other areas. This is ideal for long corridors or transmitting a signal to an adjacent building. Omnidirectional antennas (sausages) with high dBi (dBi) improve coverage in all directions, but have a narrower vertical radiation pattern, which can create a "dead zone" directly under the antenna.

There are also active signal amplifiers that connect between the router and the antenna. They amplify both the transmitted and received signals, solving the problem of asymmetrical communication. However, such devices require additional power and proper configuration to avoid introducing nonlinear distortion.

How to calculate EIRP?

The total EIRP is equal to the transmitter power (in dBm) plus the antenna gain (in dBi) minus the cable and connector losses (in dB). For example: 20 dBm (router) + 7 dBi (antenna) - 2 dB (cable) = 25 dBi. If the limit is 20 dBi, you need to reduce the router's power.

When choosing an antenna, pay attention to polarization. The antennas of the router and client devices must have the same polarization (vertical or horizontal), otherwise signal loss can reach 20 dB. In multi-story buildings, it is sometimes useful to use cross-polarization to reduce interference with neighboring devices.

Building a Mesh Network and Using CAPsMAN

For large areas, a single router, even a powerful one, won't cut it. This is where CAPsMAN (Controlled Access Point System Manager) technology comes into play. It allows you to combine multiple MikroTik access points into a single managed network with seamless roaming.

Unlike simple repeaters that cut speeds in half, CAPsMAN coordinates the operation of all access points. The client device sees one SSID and automatically switches to the access point with the strongest signal, without interrupting the connection. This is ideal for multi-story homes and offices.

Setting up CAPsMAN requires one controller device (this can be the same router that distributes the internet) and several managed access points (CAPs). All wireless network settings are configured centrally on the controller and are automatically applied to all access points.

It's important to position access points correctly. They shouldn't overlap too much on the same frequencies, otherwise interference will occur. Use channel planning: for example, on 2.4 GHz, use channels 1, 6, and 11 for adjacent access points to prevent them from interfering with each other.

Alternative methods: WDS and repeaters

If CAPsMAN seems too complex, you can use WDS (Wireless Distribution System) mode or a simple client station mode. WDS allows you to connect two MikroTik routers over the air, extending a wired network. This is slower than a wired connection, but is often the only option in older buildings.

Repeater mode (AP Bridge with WDS) allows the access point to receive a signal from the main router and broadcast it further. The downside of this method is a reduction in overall network throughput, as the radio spectrum is used for both receiving and transmitting data. Speeds can drop by half or more.

However, this method is perfectly acceptable for establishing access in a garage, sauna, or remote warehouse. The main thing is to ensure a clear line of sight between the main router and the repeater. Any obstacle between them will dramatically reduce the effectiveness of the entire chain.

⚠️ Attention: Interfaces and package names may differ between different versions of RouterOS (v6, v7, v7.10+). In newer versions, the package wifi replaces the old one wireless, and settings are made through the menu Wifi, and not WirelessAlways check the documentation for your software version.

Frequently Asked Questions (FAQ)

Why does increasing tx-power not produce any results?

Increasing the transmitter power only solves half the problem. The client device (phone) has a small antenna and can't reach the router from the same distance. The connection becomes asymmetrical: the router can hear the phone, but the router can't hear the phone.

Which band is better for long range: 2.4 GHz or 5 GHz?

The 2.4 GHz band is better for long-range coverage and wall penetration. Waves at this frequency are less attenuated by obstacles. The 5 GHz band offers higher speeds, but has a shorter range and is less effective at penetrating walls.

Is it possible to connect two MikroTik devices via Wi-Fi to share the Internet?

Yes, this is possible. One router is configured in Access Point mode, and the other in Station (client) or Station Bridge mode. This will allow you to transmit internet over the air over distances of up to several kilometers with a direct line of sight.

How often should I change Wi-Fi channels?

In a stable environment, frequent changes aren't necessary. However, if you notice a drop in speed or interference, it's worth re-scanning the airwaves. In apartment buildings, airwave load can vary depending on the time of day and neighboring activity.