Transmit power policies for stochastic stabilisation of multi-link wireless networked control systems

TL;DR

This paper develops a comprehensive framework for designing transmit power policies in wireless networked control systems, ensuring stability across complex non-linear, multi-link scenarios while minimizing power use and interference.

Contribution

It introduces a novel stability-based transmit power design method applicable to broad classes of non-linear plants and multi-link systems in WNCSs.

Findings

Derived stability conditions linking channel success probabilities and transmission rates.

Provided a design methodology integrating interference models for stabilising power levels.

Applicable to large classes of non-linear and multi-link control systems.

Abstract

Transmit power control is one of the most important issues in wireless networks, where nodes typically operate on limited battery power. Reducing communicating power consumption is essential for both economic and ecologic reasons. In fact, transmitting at unnecessarily high power not only reduces node lifetime, but also introduces excessive interference and electromagnetic pollution. Existing work in the wireless community mostly focus on designing transmit power policies by taking into account communication aspects like quality of service or network capacity. Wireless networked control systems (WNCSs), on the other hand, have different and specific needs such as stability, which require transmit power policies adapted to the control context. Transmit power design in the control community has recently attracted much attention, and available works mostly consider linear systems or specific classes of non-linear systems with a single-link view of the system. In this paper, we propose a framework for the design of stabilising transmit power levels that applies to much larger classes of non-linear plants, controllers, and multi-link setting. By exploiting the fact that channel success probabilities are related to transmit power in a non-linear fashion, we first derive closed-loop stability conditions that relate channel probabilities with transmission rate. Next, we combine these results together with well-known and realistic interference models to provide a design methodology for stabilising transmit power in non-linear and multi-link WNCSs.