Joint Scheduling and Coding for Reliable, Latency-bounded Transmission over Parallel Wireless Links

TL;DR

This paper proposes a joint packet scheduling and coding approach over multiple wireless links to ensure reliable, low-latency communication for real-time industrial applications, using a Markov Decision Process model for optimization.

Contribution

It introduces a novel MDP-based framework for joint scheduling and coding over parallel wireless links to maximize timely data delivery in latency-critical scenarios.

Findings

Optimal strategies depend on link characteristics and configurations.

Backing up high bitrate mmWave with stable sub-6 GHz links can be ineffective.

Joint design improves reliability and latency in wireless industrial communication.

Abstract

Several novel industrial applications involve human control of vehicles, cranes, or mobile robots through various high-throughput feedback systems, such as Virtual Reality (VR) and tactile/haptic signals. The near real-time interaction between the system and the operator requires strict latency constraints in packet exchange, which is difficult to guarantee over wireless communication links. In this work, we advocate that packet-level coding and packet scheduling over multiple parallel (unreliable) links have the potential to provide reliable, latency-bounded communication for applications with periodic data generation patterns. However, this goal can be reached only through a careful joint design of such mechanisms, whose interactions can be subtle and difficult to predict. In this paper we first discuss these aspects in general terms, and then present a Markov Decision Process (MDP) model that can be used to find a scheme that optimally exploits the multichannel wireless access in order to maximize the fraction of data blocks delivered within deadline. Our illustrative example is then used to show the optimal coding/scheduling strategies under different combinations of wireless links, also showing that the common solution of backing up a high bitrate unreliable mmWave link with a low bitrate more stable sub-6 GHz link can actually be ineffective in the considered scenario