Instrumentation for measuring users' goodputs in dense Wi-Fi deployments and capacity-planning rules

Before a dense Wi-Fi network is deployed, Wi-Fi providers must be careful with the performance promises they made in their way to win a bidding process. After such deployment takes place, Wi-Fi-network owners-such as public institutions-must verify that the QoS agreements are being fulfilled. We have merged both needs into a low-cost measurement system, a report of measurements at diverse scenarios and a performance prediction tool. The measurement system allows measuring the actual goodput that a set of users are receiving, and it has been used in a number of schools on a national scale. From this experience, we report measurements for different scenarios and diverse factors-which may result of interest to practitioners by themselves. Finally, we translate all the learned lessons to a freely-available capacity-planning tool for forecasting performance given a set of input parameters such as frequency, signal strength and number of users-and so, useful for estimating the cost of future deployments.