Joint Power Control and Time Division to Improve Spectral Efficiency in Dense Wi-Fi Networks

Abstract

Ubiquitous densification of wireless networks has brought up the issue of inter-and intra-cell interference. Interference significantly degrades network throughput and leads to unfair channel resource usage, especially in Wi-Fi networks, where even a low interfering signal from a hidden station may cause collisions or block channel access as it is based on carrier sensing. In the paper, we propose a joint power control and channel time scheduling algorithm for such networks, which significantly increases overall network throughput while maintaining fairness. The algorithm is based on branch-andbound global optimization technique and guarantees that the solution is optimal with user-defined accuracy.

Cloud-based Management of Energy-Efficient Dense IEEE 802.11ax Networks

“…Collisions inherent to the legacy solution are avoided, but no gain in throughput is achieved, because of the fixed transmit power. The curves for both the solutions with joint power control and scheduling (developed in [11] and in this paper) are quite close to each other (except for the case with a single AP). For both solutions, tuning transmit power increases the mean throughput from 30 Mbps up to 50 Mbps for a high number of APs.…”

“…We schedule transmissions of APs in order to maximize geometric mean throughput. For that, we also solve the optimization problem described in [11]. 3) Power control and scheduling.…”

“…3) Power control and scheduling. In addition to scheduling, we tune transmit power as described in [11]. 4) Energy-efficient power control and scheduling.…”

“…Specifically, since Wi-Fi implements CSMA/CA, regulatory bodies put limits on the sensitivity threshold. An example of a solution to the GEE problem is shown in paper [11], where an algorithm based on the branchand-bound technique was proposed to allocate power in Wi-Fi networks dynamically. Even with a constant traffic load such an algorithm dynamically varies the transmit power and, thus, obtains higher efficiency.…”

“…where g(r, w) is a non-decreasing function. It means that, if condition (11) is not met at some point (r, w), then it is not satisfied at any other point (r , w ) such that (r , w ) (r, w).…”