Fast centralized authentication in Wi-Fi HaLow networks

In early 2016 Wi-Fi Alliance announced a new technology - Wi-Fi HaLow - which aims to master the raising Internet of Things market with its tremendous number of devices. This technology brings revolutionary changes to Wi-Fi, improving transmission reliability and power efficiency in scenarios with thousands of sensor stations being connected to a single access point. However neither novel channel access methods, nor advanced power management schemes can be used until the stations are connected to the access point, because the access point may not know that the stations exist, to say nothing about their capabilities. Nevertheless, it may happen that a large group of sensor stations are simultaneously trying to connect to the access point, which inevitably leads to continuous collisions and finally to extremely long connection process. This problem has been addressed by the technology developers which designed the Centralized Authentication Control protocol. The protocol provides the access point with an opportunity to hasten the process by managing the ratio of stations which are allowed to start establishing a connection. In this paper, we study how the number of successes depends on this ratio and develop two algorithms, which hasten connection process close to the theoretical limit.

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.