Inversely proportional setting (IPS) of the transmission power and carrier sense threshold (CST) to a portion of access points/stations is discussed through numerical evaluation and experiments to examine coexistence with legacy devices. In densely deployed wireless local area networks (WLANs), tuning CST is a promising approach to facilitate spatial channel reuse. Particularly, IPS of the transmission power and CST keeps symmetric carrier sensing relationship between any two transceivers, and thus provides a novel solution for the starvation due to asymmetric carrier sensing relationship. We first model the throughput of two transmitter-receiver pairs when applying IPS. In addition, through experiments, we verify the throughput model and confirm that IPS does not cause throughput starvation even when applying IPS only to some APs and/or STAs.