Monday, March 18, 2013

Video Blog: High-Density Wi-Fi Design Part 1 - Forecasting AP Capacity

In my previous post, Design your WLAN for High Capacity, I outlined the increasing demands being placed on modern enterprise WLANs caused by the growth in the number of Wi-Fi connected devices, the proliferation of mobile devices and BYOD, and the increasing reliance on the WLAN as the primary network for users in the enterprise. As described in the Aerohive High-Density Wi-Fi Design and Configuration Guide, the key to supporting this increased demand is to design the WLAN for capacity rather than simply coverage.

The first step in designing a WLAN to meet capacity demands is to perform adequate requirements gathering. This starts with a proper understanding of client device capabilities. Because RF is a shared environment, the capacity is determined by the capabilities of the AP infrastructure and the client devices, application bandwidth requirements, and the resulting airtime utilization that results from their unique combination.

In this first of three videos on high-density Wi-Fi design, I describe how these variables interact and can be used to derive a preliminary forecast of the required AP capacity to support the intended network load. I also walk through a few examples to highlight how to apply this method to both homogenous and heterogeneous client environments.

The resulting AP capacity forecast is a starting point to aid the RF design and site survey process. The value in deriving the AP capacity forecast is to ensure that capacity needs are properly accounted for in the site survey process. For example, even though one AP may provide adequate coverage in a university lecture hall, several more APs may be required for capacity. Historically, RF site surveys have only focused on providing adequate RF coverage for the physical area, which may provide sufficient signal in all desired locations but lack AP and channel capacity to successfully support the client and application load.

Once you’ve watched the examples in the video, walk through a few of your own scenarios using the requirements gathering worksheets in the appendix of the Aerohive High-Density Wi-Fi Design and Configuration Guide.

Stay tuned for the remaining two videos in this series, where I’ll cover key RF design and network configuration principles for high-density networks.

Read the Entire High-Density Wi-Fi Design Series:


Full Disclosure - This video was created in cooperation with Aerohive Networks, my current employer. 


  1. Hey! Andrew

    Many thanks for your great sharing!!

    Do you know where I can something like "Aerohive Mesh deployment guide"
    Or something like this for me to download.

    I do have outdoor project with aerohive equiptment. To tell the true, for cisco such document like this is very easy to find but not for aerohive.

    We do have some issues like L2 mac flaping on L2 switch for duplication mac address when MESH connection change data flow to different AP-portal.

    Really appreciated if u have outdoor mesh best practice document.

    PS. AP-170 comes without any LED status... OH!!!!!

    1. I would ask this question on the Aerohive community site:

  2. Hi Andrew,

    Thank you for the video. I have a question about the 2 stations sharing the airtime, which results in a throughput divided by 2.

    I agree if the 2 stations have the same access time (same TXOP). But if a station can transmit only one frame (or one aggregated frame) per access round (TXOP=0), this will result in a worse case where both stations will have the same throughput. This common throughput will be less than 30 Mbps.

    Do you agree on that?

    Thank you.