Two-Level Priority Coding for Resilience to Arbitrary Blockage Patterns

TL;DR

This paper develops a multilevel diversity coding scheme to enhance reliability in low-latency communication systems facing arbitrary blockages, with a focus on two priority levels over multiple network paths.

Contribution

It characterizes the capacity region for two priority levels over three paths and identifies conditions where superposition coding is capacity-achieving for any number of paths.

Findings

Superposition coding achieves the capacity region in general cases.

Network coding is necessary only in specific corner cases.

Conditions are identified where simple superposition coding is optimal for multiple paths.

Abstract

Ultra-reliable low-latency communication is essential in mission-critical settings, including military applications, where persistent and asymmetric link blockages caused by mobility, jamming, or adversarial attacks can disrupt delay-sensitive transmissions. This paper addresses this challenge by deploying a multilevel diversity coding (MDC) scheme that controls the received information, offers distinct reliability guarantees based on the priority of data streams, and maintains low design and operational complexity as the number of network paths increases. For two priority levels over three edge-disjoint paths, the complete capacity region is characterized, showing that superposition coding achieves the region in general, whereas network coding is required only in a specific corner case. Moreover, sufficient conditions under which a simple superposition coding scheme achieves the capacity for an arbitrary number of paths are identified. To prove these results and provide a unified analytical framework, the problem of designing high-performing MDC schemes is shown to be equivalent to the problem of designing high-performing encoding schemes over a class of broadcast networks, referred to as combination networks in the literature.