# Performance analysis of IEEE 802.11ax heterogeneous network in the presence of hidden terminals

## TL;DR

This paper analyzes the impact of hidden terminals on IEEE 802.11ax network performance and proposes increasing the carrier sensing threshold during association to reduce uplink collisions.

## Contribution

It introduces a novel mechanism of increasing the carrier sensing threshold to mitigate hidden terminal effects in IEEE 802.11ax networks.

## Key findings

- Significant reduction in collision probability with the proposed method
- Improved uplink throughput in the presence of hidden terminals
- Mechanism effective at high traffic loads

## Abstract

Performance improvement has been among the foci of all previous amendments of IEEE 802.11 protocol. In addition, the draft high efficiency (HE) amendment IEEE 802.11ax, proposed by TGax, aims at increasing network performance. One of the main obstacles to improving spectral and power efficiency is the presence of hidden terminals which degrade throughput, in particular in uplink transmission. IEEE 802.11ax does provide mechanisms such as trigger based uplink transmission that mitigate this degradation to some extent, but are incapable of eliminating it, esp. at high arrival rates. To combat the hidden terminal problem, we propose to increase the carrier sensing threshold (CSTH) of STAs during association with an HE access point. Our results confirm that the proposed mechanism can lead to significant reduction of collision probability in uplink transmission.