SDMAC: A Software-Defined MAC for Wi-Fi to Ease Implementation of Soft Real-time Applications

TL;DR

SDMAC introduces a software-defined MAC layer for Wi-Fi on Linux PCs, enabling precise control over transmission timing to support soft real-time applications in distributed control systems.

Contribution

The paper proposes a novel SDMAC architecture that allows user-space control of Wi-Fi MAC operations, facilitating real-time communication mechanisms.

Findings

Preliminary implementation on Linux PCs shows viability.

Performance is suitable for soft real-time applications.

Enables new control mechanisms like deterministic scheduling.

Abstract

In distributed control systems where devices are connected through Wi-Fi, direct access to low-level MAC operations may help applications to meet their timing constraints. In particular, the ability to timely control single transmission attempts on air, by means of software programs running at the user space level, eases the implementation of mechanisms aimed at improving communication timeliness and reliability. Relevant examples are deterministic traffic scheduling, seamless channel redundancy, rate adaptation algorithms, and so on. In this paper, a novel architecture is defined, we call SDMAC, which in its current embodiment relies on conventional Linux PCs equipped with commercial Wi-Fi adapters. Preliminary SDMAC implementation on a real testbed and its experimental evaluation showed that integrating this paradigm in existing protocol stacks constitutes a viable option, whose performance suits a wide range of applications characterized by soft real-time requirements.