Date of Award

1-2026

Document Type

Thesis

Publisher

Santa Clara : Santa Clara University, 2026

Degree Name

Master of Science (MS)

Department

Computer Science and Engineering

First Advisor

Behnam Dezfouli

Abstract

Modern Wi-Fi applications require tight latency bounds and predictable throughput, and they rely on a mix of transport protocols (e.g., TCP Cubic, BBR, New Reno, and UDP) whose performance is highly sensitive to MAC-layer behavior. The forthcoming 802.11bn amendment introduces Prioritized EDCA (P-EDCA) to reduce latency for high-priority traffic, yet its cross-layer impact on transport performance remains insufficiently understood. This thesis evaluates the performance of TCP and UDP traffic operating over both EDCA and P-EDCA. Our results show that (i) both TCP and UDP traffic exhibit strong sensitivity to P-EDCA configuration, with uplink tail latency varying widely; (ii) by reducing MAC-layer frame drops, P-EDCA suppresses TCP retransmissions and RTOs for high-priority uplink flows, allowing the congestion window to grow and improving both goodput and tail latency; (iii) the relative performance of TCP congestion control algorithms shifts depending on the MAC-layer policy; (iv) bandwidth fairness between TCP and UDP improves as TCP starvation is mitigated using P-EDCA; and (v) aggressive P-EDCA configurations introduce performance trade-offs, reducing best-effort TCP throughput when voice flows dominate contention and increasing latency for high-throughput UDP flows when the eligibility conditions for invoking P-EDCA are relaxed. These findings illustrate how MAClayer latency optimizations propagate to the transport layer in non-intuitive ways, highlighting the need for MAC and transport layer aware application development.

Download

Share

COinS