Too Many APs Can Be a Bad Thing

Access points (APs) are devices that provide WiFi coverage to a certain area.  They create a wireless local area network (WLAN) that mobile devices (laptops, smartphones, IoT devices, etc.) search for and connect to in order to have WiFi access.  Since APs provide wireless coverage, it can be tempting to think that the best way to offer strong coverage is to add as many APs as possible to a space, but that isn’t always the case.  There comes a point when adding APs actually becomes counterproductive.

This is because, when APs are placed near each other, they can interfere with each other which can either be: 

• Co-channel Interference (CCI) – this occurs when two or more APs are using the same channel.  This causes delayed network responses as APs and clients have to wait until the channel is clear to transmit.  To resolve this issue, change the channel on one of the APs.
• Adjacent Channel Interference (ACI) – this occurs when two or more APs are on different channels, that are adjacent to each other.  This can lead to degraded performance. To avoid ACI, avoid setting adjacent APs on adjacent channels. On the 2.4GHz network, there are only 3 channels that do not overlap (1, 6, and 11), while the 5GHz offers over 24 non-overlapping channels in the United States (the count varies in different regions of the world), and 

Even with 24 channels to choose from and enough APs in a given space, it may not be impossible to avoid CCI or ACI completely, especially if you are operating in an environment like a multi-tenant office where you don’t have control over every AP.  Another important note, it can be tempting to avoid the 2.4GHz spectrum altogether, but some devices are only 2.4GHz compliant. How do you know if CCI or ACI is slowing down your network? How do you determine how many APs are too many?

First, you need continuous, 100% network visibility.  This is the only way to know exactly what is occurring on a network and how to successfully resolve any issues.  Wyebot’s Wireless Intelligence Platform™ (WIP) offers proactive 24/7 detection, notification, and mitigation. All data is saved, giving you the ability to review data from the past day, week or month.  This includes data on APs, connected devices, and airtime utilization. With complete, real-time visibility, and historical data, it is possible to determine what the network is being asked to support, how that has changed, and how many APs are truly necessary to provide coverage.

Second, you need to know the capabilities of each device on the network.  This can tell you how to best design and/or configure your WiFi network with the right combination of 5GHz and 2.4GHz radios.  WIP’s fingerprinting ability identifies each device on the network and its unique capabilities. Its device pattern recognition ensures that any device capability changes, such as after an upgrade, are recognized and analyzed, supporting complete WiFi ecosystem visibility.

Third, you can adjust the power of an AP so that it transmits to a smaller area, operating in a “micro cell.”  This can be beneficial in environments such as college dorms when some common deployments see an AP in every room, or a mix of APs in rooms and hallways.  Even with a micro cell architecture though, it is important to know device capabilities and maintain network visibility to ensure that the AP coverage is sufficient.

At Wyebot, we’ve designed a vendor agnostic solution that can assist IT in determining the right number of APs for any location.  Use WIP today to manage interference and optimize your network.