I. Introduction
Being the most widely used wireless technology operating in license-exempt bands, Wi-Fi tries to expand its area of applicability to typical Internet of Things scenarios [1]. Specifically, in early 2016 Wi-Fi Alliance announced a new technology - Wi-Fi HaLow — which is based on the novel IEEE 802.11ah standard. Originally planned as a set of small refinement of Wi-Fi operation, the standard turned out to be a heavy document touching almost all Wi-Fi functionality. In particular it provides a palette of new methods improving transmission reliability, spectrum efficiency and power consumption in a scenario when up to 8000 of power-limited sensor stations (STAs) are connected to a single access point (AP). However novel channel access or power management techniques cannot be used before the STAs are connected to the AP. In other words, the AP needs to know that a particular STA is present, and which techniques it supports.