Sustainable Throughput of Wireless LANs with Multi-Packet Reception Capability under Bounded Delay-Moment Requirements

TL;DR

This paper rigorously analyzes WLAN throughput under non-saturated traffic, revealing that saturation throughput is not a reliable capacity measure and introducing SBMD and SBDJ throughputs to better reflect actual user experience, especially with multi-packet reception capabilities.

Contribution

It introduces the concepts of SBMD and SBDJ throughput, extending the analysis of MPR's benefits from saturation to non-saturation conditions, ensuring finite delay metrics.

Findings

Saturation throughput does not accurately represent WLAN capacity under non-saturation.

SBMD and SBDJ throughputs scale super-linearly with MPR capability.

MPR significantly enhances WLAN capacity in both saturated and unsaturated scenarios.

Abstract

With the rapid proliferation of broadband wireless services, it is of paramount importance to understand how fast data can be sent through a wireless local area network (WLAN). Thanks to a large body of research following the seminal work of Bianchi, WLAN throughput under saturated traffic condition has been well understood. By contrast, prior investigations on throughput performance under unsaturated traffic condition was largely based on phenomenological observations, which lead to a common misconception that WLAN can support a traffic load as high as saturation throughput, if not higher, under non-saturation condition. In this paper, we show through rigorous analysis that this misconception may result in unacceptable quality of service: mean packet delay and delay jitter may approach infinity even when the traffic load is far below the saturation throughput. Hence, saturation throughput is not a sound measure of WLAN capacity under non-saturation condition. To bridge the gap, we define safe-bounded-mean-delay (SBMD) throughput and safe-bounded-delay-jitter (SBDJ) throughput that reflect the actual network capacity users can enjoy when they require finite mean delay and delay jitter, respectively. Our earlier work proved that in a WLAN with multi-packet reception (MPR) capability, saturation throughput scales super-linearly with the MPR capability of the network. This paper extends the investigation to the non-saturation case and shows that super-linear scaling also holds for SBMD and SBDJ throughputs. Our results here complete the demonstration of MPR as a powerful capacity-enhancement technique for WLAN under both saturation and non-saturation conditions.