Key takeaways:
External antennas can improve wireless network performance in specific settings. But unfortunately, they are often misunderstood and sometimes not correctly implemented in WLAN strategies. Nevertheless, used correctly, external antennas provide more flexibility and control than exclusively relying on internal antennas.
These antennas can especially benefit high-density areas, like stadiums, conference centers, lecture halls, arenas, offices, and airports that see significant traffic. Networks like these must provide additional capacity beyond what would be accommodated for a coverage-oriented design.
Let’s go over high-density Wi-Fi design, how external antennas help, and a few best practices for using them properly.
When simply meeting a coverage requirement isn’t enough for a large or congested space requiring additional capacity, wireless engineers start with adding more access points (APs) to respond to the client density. Then, they consider band—the 2.4 GHz band isn’t going to work well for high-density areas since it’s easily congested. 5 GHz and now 6 GHz are the only bands that can provide enough capacity in high-density designs.
Another consideration for these areas is the type of antennas used for access points. Internal antennas create a fixed coverage pattern that only changes based on how the AP is mounted. In contrast, an external antenna on an access point provides greater control. You can customize the shape and pattern to address particularly challenging coverage areas. External antennas can also help protect APs from harsh weather conditions since access points and antennas can be mounted separately.
Keep in mind that wireless engineers should use narrow beamwidth antennas for particularly high-density areas. These emit a narrower radio frequency beam that limits the signal, helping target a particular area to limit the number of clients that will connect and reduce co-channel interference. Some external antennas can be mounted on the wall.
As with any Wi-Fi equipment deployment, there are some best practices to follow regarding antennas. First, remember that placing antennas and access points near metal beams and structures can disrupt the signal, so be careful around obstructions.
Also, consider how dual-band antennas work and how to connect them to access point ports. Dual-band antennas have connectors that are either suited for both 2.4 GHz and 5 GHz or completely separate, with some for 2.4 GHz and others for 5 GHz. Dual-band access points can have similar set-ups, plus a third option: software-controlled connectors, which allow you to assign ports to a particular frequency.
You can connect a 2.4 GHz port from the antenna to a 2.4 GHz port on the access point, and the same goes for 5 GHz ports. You can also connect each to any port compatible with both 2.4 GHz and 5 GHz bands. But you can't connect a 2.4 GHz antenna port to the 5 GHz port on the access point, and vice versa.
From the access point perspective, you can connect a dual-band port to either the 2.4 GHz or 5 GHz band, as long as you’ll be running that particular band.
Access points generally have two to eight antenna ports with MIMO (multiple input, multiple output) capabilities. If an antenna is instead a single-element model, you can still use it—but only if you combine multiple single-element antennas to build your own MIMO antenna, essentially.
It’s also important to use only one type of dipole antenna. Employ the same type on all the ports, and aim them all in the same direction. Don’t point two antennas down opposing directions of a hallway, for instance.
If you decide to experiment with the polarization of antennas, it may take some trial and error to correctly position horizontal and vertical antennas. Remember that building elements tend to be vertical, and radio waves can bounce around and align themselves based on that orientation.
External antennas can help WLAN designers achieve better results for congested or large outdoor areas, but they should be deployed appropriately. And beyond best practices like these, it’s also important to measure how the WLAN performs—including how end-users experience connections. 7SIGNAL's wireless network monitoring provides this crucial visibility.
The platform continuously tests and monitors connections, allowing you to respond to issues quickly and identify problems that can be solved with simple changes or better WLAN design. Our solutions report on over 600 KPIs that enable faster maintenance and improved performance.
Get in touch with 7SIGNAL to learn more about our wireless network monitoring products, including Sapphire Eye® and Mobile Eye®.
7SIGNAL® is the leader in wireless experience monitoring, providing insight into wireless networks and control over Wi-Fi performance so businesses and organizations can thrive. Our cloud-based wireless network monitoring platform continually tests and measures Wi-Fi performance at the edges of the network, enabling fast solutions to digital experience issues and stronger connections for mission-critical users, devices, and applications. Learn more at www.7signal.com.