  The sixth generation (6G) mobile communication networks are expected to
intelligently integrate into various aspects of modern digital society,
including smart cities, homes, healthcare, transportation, and factories. While
offering a multitude of services, it is likely that societies become
increasingly reliant on 6G infrastructure. Any disruption to these digital
services, whether due to human or technical failures, natural disasters, or
terrorism, would significantly impact citizens' daily lives. Hence, 6G networks
need not only to provide high-performance services but also to be resilient in
maintaining essential services in the face of potentially unknown challenges.
This paper introduces a comprehensive concept for designing resilient 6G
communication networks, summarizing our initial studies within the German
Open6GHub project. Adopting an interdisciplinary approach, we propose to embed
physical and cyber resilience across all communication system layers,
addressing electronics, physical channel, network components and functions,
networks, services, and cross-layer and cross-infrastructure considerations.
After reviewing the background on resilience concepts, definitions, and
approaches, we introduce the proposed resilience-by-design (RBD) concept for 6G
communication networks. We further elaborate on the proposed RBD concept along
with selected 6G use-cases and present various open problems for future
research on 6G resilience.
