Wi-Fi Capacity Planning Done Right

by Ubiquiti Employee on ‎05-31-2017 08:15 PM (42,060 Views)

Modern Wi-Fi networks are complex beasts. Despite all the fancy new features in products, the technology is only becoming more complex and the demands on the network are only growing. Wi-Fi is the most heavily used method to transport user data today, eclipsing cellular and LAN traffic volumes according to multiple reports from analysis firms including Cisco, Ofcom, Mobidia, Ovum, and others. Meanwhile, the technical complexity contained within the IEEE 802.11 standard results in a technical document that is over 3,200 pages long!  This means deploying a network right is no easy task.


One of the most difficult aspects to get right when deploying a Wi-Fi network is understanding capacity requirements. It is not sufficient enough to use rule-of-thumb guidelines based on number of clients per access point or number of access points per square foot/meter since they often result in networks that do not adequately meet actual end-user demands and perform poorly. More rigor is required while maintaining simplicity of use so that most network administrators can be confident of a successful outcome.


Essential to wireless network performance and capacity planning is understanding the interaction between access point capabilities, network configuration, client device capabilities, and the RF environment. Many administrators still focus exclusively on the access point capabilities and, to a lesser extent, network configuration and RF environment. However, it is really the interaction of all four aspects that determines network performance. Complexity is introduced because wireless client devices have a wide range of capabilities, including protocol versions from 802.11b through 802.11ac Wave 2, from 1-3 spatial streams, 20 vs 40 vs 80 MHz channel width support, single-band vs dual-band support, and antenna design characteristics that vary between devices based on form-factor and manufacturer product objectives. In addition, the RF environment is always changing, even for stationary devices, because of signal reflections, multipath, and other objects moving within and through the physical environment. What this really means is that capacity is consumed in a dynamic fashion on the WLAN, each client consuming capacity differently and varying by the microsecond as the RF environment changes and affects client signal-to-noise ratio (SNR) and data rate selection.


Two years ago, the Revolution Wi-Fi Capacity Planner ™ was released as a proof-of-concept tool for free to the community, with the objective to promote better capacity planning for every WLAN. It provides a simple tool to estimate client airtime utilization and understand how many APs are required given the variables described previously: AP capabilities, network configuration, client capabilities, and RF environment. The most critical aspect of the tool is to define the client device mix, which can be as simple as generic device types (laptops, tablets, smartphones, etc.) or as comprehensive as possible if the administrator has reliable data on the specific devices in use.


Ubiquiti has partnered with Revolution Wi-Fi to release version 2 of the capacity planner, that improves the tool by adding the following features:


Capacity Analysis – visualize network utilization and a breakdown of capacity by client devices with varying capabilities. Analysis data is provided by protocol version, frequency band, application type (bulk data vs. voip/real-time), spatial streams, and channel width. Quickly and easily determine the impact of legacy clients on the network!

Mesh Network Planning
– plan 5 GHz single-channel mesh networks to determine how many root nodes are necessary to meet capacity requirements and the per-hop mesh network performance. Use an existing client capacity plan or manually configure mesh network capacity requirements.

Improved Growth Planning
– networks are constantly changing and the capacity plan that you develop today should accommodate future growth. The capacity plan now provides a detailed breakdown of capacity per-radio, including the amount of frequency reuse required to achieve the forecasted capacity, as well as the capacity available for future growth given the client mix modeled by the user.


Exportable PDF Reports
– save the capacity plan data, capacity analysis visualizations, and mesh network plan as a PDF report. Great for project documentation and for communicating with management to explain technical concepts in an easy-to-understand format to influence budgeting and planning.



Head on over to the Revolution Wi-Fi Capacity Planner ™ webpage to learn more, download this free tool, and start deploying better Wi-Fi networks! Also, check out the videos that help explain these concepts in more depth.


And stay tuned for more, as Ubiquiti and Revolution Wi-Fi continue to collaborate on bringing Wi-Fi capacity planning to Ubiquiti users!


--Andrew von Nagy




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Andrew von Nagy is an accomplished computer networking professional with over 15 years of experience in the education, retail, manufacturer, and service provider industries. He is a recognized wireless LAN networking expert having achieved two of the industry's highest certifications, CCIE #28298 (Cisco Systems) and CWNE #84 (CWNP). Andrew writes about relevant Wi-Fi industry topics on the Revolution Wi- Fi blog and speaks at various industry conferences. He is the creator of the Revolution Wi-Fi Capacity Planner, one of the first tools to help network administrators determine capacity requirements on their WLAN using predictive modeling and analysis. He has also served as a technical editor for wireless LAN publications, including the CWNA Study Guide: 3rd Edition (ISBN #978- 1118127797), 802.11n: A Survival Guide (ISBN #978-1449312046), and the CWNA Study Guide: 4th Edition (ISBN #978-1118893708).