CTS 226: Wi-Fi Capacity Planning

What is Wi-Fi Capacity Planning? In this episode, we discuss what Wi-Fi capacity is, how it can be done, and what are some of the “gotchas” when you are doing capacity planning. When it comes to Wi-Fi capacity planning, many rely on the built-in tools to help us determine how many access points (APs) are required to meet the capacity of a given area. A lot of planning goes into the study of the traffic being generated by the Wi-Fi clients and the APs. Clients have a varying degree of capabilities which much be considered, how many of those clients will be in an area, and what applications they will be using. Why do we do capacity planning studies Air time is our limited resource in Wi-Fi and we want to be sure that we are not going to saturate it with a poor Wi-Fi design. We do capacity planning to know how many radios we will need and we incorporate that information in our RF design with the proper equipment. Channel reuse will be critical as to not cause excessive co-channel interference. If our capacity requirements are high, it would mean we need to adjust the RF design so we can actually meet these high requirements in the real world. Some examples could be high-density open spaces with bandwidth-hungry clients. When do you do a capacity planning Different scenarios call for capacity planning such as working in Wi-Fi only open spaces, or carpeted environments. When we expect a lot of clients on the Wi-Fi network utilizing critical applications we also perform capacity planning. Sometimes it isn’t a high-density environment. It could be capacity-based because of the application usage with a specific number of clients. In reality, you will see that we tend to over-engineer our solution. The reality will usually have a lower utilization of Wi-Fi but we must talk to the stakeholders about expectations. Where capacity might not be needed is a warehouse. Most of the time that is coverage based with low bandwidth requirements. Gotchas When we do capacity planning they are just estimations. There are a lot of moving pieces and it could be hard to get very accurate. A lot of time must be taken to research the required capacity and include growth as well. How do you plan for capacity when you don’t know which devices will connect to the Wi-Fi network, such as a BYOD environment. That is very much a large guesstimate and can be based on the number of devices in a given area. Currently, it is difficult to do capacity planning with Wi-Fi 6. Will we need to do it? Maybe. Capacity planning needs to be made for areas of the same density. If you have different areas expecting different density of devices, you have to perform multiple capacity studies or have the design software do it for you. Maximum device capabilities are used when performing capacity planning. In the real world, devices might not always use these capabilities. Additionally, when using Ekahau, the capacity would be based on the number of devices specified at their max SLA. Tools * Capacity Planner from Revolution Wi-Fi (Andrew Von Nagy)* http://www.revolutionwifi.net/capacity-planner* Capacity planner within Ekahau Pro* Capacity planner within iBwave Wi-Fi* Educational tool – AirTime Calculator : https://gjermundraae...