Evangelos Bitsikas, Adam Belfki, Aanjhan Ranganathan
M2M deployments such as drone swarms demand mission-critical communication: km-scale range, strong per-device identity and mutual authentication, and deterministic QoS for bandwidth-intensive payloads. Cellular 5G uniquely satisfies all of these, yet it has seen limited adoption in autonomous fleets. The barrier is not capability but resilience: today's 5G networks assume fixed infrastructure, and when the base station fails, recovery is uniquely complex. Unlike simpler wireless protocols where devices can transparently switch nodes, 5G failure requires reconstructing distributed state such as authentication contexts, QoS bindings, tunnels, and RRC state machines across the fleet, a process that no existing system automates. We present Dyna-5G, which makes this happen. Dyna-5G is the first 5G Standalone-compliant framework for dynamic role switching in M2M fleets, where any device can assume the role of 5G Core, RAN, or UE at runtime. It orchestrates failure detection, leader selection, and coordinated state teardown and re-establishment, all without modifying 3GPP protocols. We evaluate Dyna-5G on a high-fidelity software emulation testbed, with Open5GS and srsRAN, across hundreds of trials with up to 10 drones. Control-plane overhead averages 0.47 Mb/s (approximately 0.47% of a 100 Mb/s bearer), while failure recovery completes in about 2.5 s, of which approximately 86% is due to stack-dependent cellular procedures. Dyna-5G's orchestration logic itself adds only about 175 ms per reconfiguring role. All tested missions complete successfully, even under injected leader crashes.