How to scale a Wi-Fi network

Although it’s tempting to just deploy more access points (APs) when expanding your Wi-Fi network, there are many considerations to take in account first in order to get a high-performing result without overspending.

Step one is to clearly understand what you are trying to achieve, then analyze the current setup so you know how well the network serves the coverage area, and only then go about designing and deploying the APs.

Set your goals

Scaling up a Wi-Fi network can take many forms. It might mean deploying an entirely new network in a new facility, extending an existing network geographically or increasing its density to serve more clients in the same area. Each will have different requirements, and in order to set them properly for your project, you need to define them.

You need to find out how many clients will use the network at any given time, where they might be clustered together, and the bandwidth demands of the applications they use. For the most cost-effective network, an important goal is providing good coverage using the fewest number of APs.

Analyze the current setup

Site survey

Wi-Fi surveying is important in most instances to show how well the deployed APs provide coverage. If you don’t already have heatmaps for your current network you should do a survey and create some to get a baseline of performance and to ensure the network is healthy. These surveys can help find the optimum locations for new access points if they are needed. These tips on how to conduct a survey and avoid interference and dead spots can help.

With a Wi-Fi network upgrade, you should assess the space that needs improved coverage, think about the number of clients that will be present in each area, and estimate about how many APs are needed those areas to support those clients.

How many APs?

You can start calculating the number of APs that you’ll need by doing some math to get rough client-to-AP ratios. Though AP vendors may say they can handle 100 to 300 or even more users per AP, real-world applications mean you’ll probably want to support 15 to 50 clients per AP radio depending on what applications the clients are using. The ratio might be higher when using Wi-Fi 6 (802.11ax) APs and clients in high-density environments like stadiums.

Scaling up the network doesn’t necessarily mean ripping and replacing all the existing APs, but before you do, evaluate the age and capabilities of the current APs. Consider replacing all of them at the time of the scaling if they support only up to 802.11g, and maybe even consider replacement if it’s 802.11n. If you do end up wanting to replace the APs, carefully evaluate and compare features, and think about futureproofing by projecting how Wi-Fi use will change over time. Also consider the Wi-Fi standards that the clients support.

As a rule, do anything you can to help increase capacity of the network without adding more APs. The fewer radio-frequency signals flying around, the less the chance they will compete and cause co-channel interference, and the better off the network will be. Some ways to avoid this interference are tuning down power levels and even disabling the 2.4GHz band altogether on some APs. You should also be very thoughtful about where you place the APs because placing them in spots where you can utilize the building or furniture to cause attenuation, can help to better contain the signals from each AP.

Also, you want to minimize co-channel interference by using Wi-Fi analyzers to insure the coverage of the APs overlap enough to ensure seamless roaming, but not enough to interfere with each other. You also want to be sure APs aren’t broadcasting a much higher power level than the typical client used in the network. Aim for the APs and the clients to have about equal reach in their transmission ranges.

Check the capacity of the wired network

While you are evaluating your existing Wi-Fi gear, be sure to do the same for the networking infrastructure it connects to. Consider the number of APs that your wireless controller is capable of supporting. The upgrade may push it beyond its limits, and so it may have to be replaced.

Also, calculate the network switch capacity that new or additional APs will need, and make sure there are sufficient and large enough switch ports to handle the upgrade. Remember that placing APs may require new Ethernet cable runs between them and a switch. If the APS support Wi-Fi mesh or wireless distribution system (WDS) mode where certain APs receive their LAN connection wirelessly, they can be used as a temporary fix to attach the new gear until the Ethernet can be pulled. Wi-Fi mesh and WDS are not recommended for permanent use unless it’s impossible to run ethernet out to the APs. 

Extending coverage of existing Wi-Fi

If you want to slightly extend the Wi-Fi coverage area say 100 hundred feet or less, first analyze the heatmaps to see whether tweaking the existing APs could accomplish the task. Making a few minor AP moves and increasing power levels slightly will push out the coverage a little further. If you want significantly more coverage, you’ll probably have to add more APs and run more cables after doing some surveying for find optimum locations.

Extending Wi-Fi outdoors with existing APs

If you’re looking to expand Wi-Fi coverage outside or to an outbuilding without network connectivity, there are several ways to go about it depending on how far from the main network you need coverage. If you only need a few hundred feet of coverage away from a building with network connectivity, consider running the Ethernet through the exterior wall and mounting outdoor-rated APs on the exterior of the building. Most likely you want to utilize directional antennas pointing to where the clients will be.

For reaching distances more than a few hundred feet from the main building, consider running Ethernet out to the desired AP locations. If that’s not feasible, see if the AP supports wireless mesh or WDS functionality for the backhaul instead of Ethernet. For longer distances, you could utilize special long-distance APs like wireless ISP (WISP) equipment.  

If the desired outside area is too far for truly extending the current Wi-Fi, maybe consider using a separate cellular-based internet connection for the outside area. You could utilize an enterprise-level router with cellular support for the WAN connection, or for smaller and simpler needs just use a consumer-based Wi-Fi hotspot.

Adding Wi-Fi for whole new sites

If you’re expanding your Wi-Fi by adding new locations with no existing Wi-Fi network, you’ll need to do some site surveying to find the optimum AP locations. Also, consider uniformity of equipment across all of your sites. If you already utilize a Wi-Fi brand with a cloud-based controller system, that can certainly make managing your existing sites plus your new ones easier. If you don’t already have a cloud-based solution for your Wi-Fi management, and you have multiple sites, consider moving towards one. This is a major feature to consider if you’re needing to upgrade a network.