In RouterOS, the parameter channel-width refers to the channel bandwidth used by a wireless interface. This setting is essential for setting up Wi-Fi networks, as it affects both the network's performance and its ability to handle interference and coexist with other wireless networks in congested areas. Here I detail how it works and its impact:

Principal function

• Determine the Bandwidth: channel-width specifies the range of frequencies that a wireless network will use to transmit data. A wider channel width allows for higher data transfer rates, potentially improving network performance.

Impact on Performance and Coexistence

• Performance: A wider channel can significantly increase wireless network speed, allowing compatible devices to achieve higher data rates. This is particularly useful for bandwidth-intensive applications, such as streaming high-definition video or transferring large files.
• Interference and Coexistence: Using wider channels also has the potential to cause and suffer more interference as it takes up more of the wireless spectrum. In areas with many Wi-Fi networks, setting a wider channel could lead to greater interference with other networks, negatively affecting performance.

Common Channel Width Options

• 20 MHz: It is the standard bandwidth and the most compatible. It offers a lower maximum speed but is more resistant to interference. It is suitable for congested areas.
• 40 MHz: Offers higher speeds by doubling the channel width. However, the possibility of interference with other networks increases.
• 80 MHz and 160 MHz: Available in the latest standards such as 802.11ac (Wi-Fi 5) and 802.11ax (Wi-Fi 6), these channel widths allow for even higher speeds but are more susceptible to interference and require a cleaner RF environment to function effectively.

Configuration Considerations

• Device Compatibility: Not all wireless devices support wide channel widths, especially older devices. It is important to consider device compatibility when choosing channel width.
• Local Regulations: Available spectrum and regulations vary by country. Some channel widths, especially wider ones, may not be permitted in all areas.
• RF environment: Performing an analysis of the RF spectrum to understand the level of congestion and the presence of other signals can help you make an informed decision about the best channel width to use.

Correctly configure the channel-width in RouterOS is a balance between maximizing network performance and minimizing interference with other networks, all while complying with local regulations and considering the capabilities of client devices.