When disasters destroy cellular towers and WiFi infrastructure, survivor devices lose their only path to a monitoring system at precisely the moment continuous health and distress reporting is most critical. V. O. I. D. (Vital Offline Information Dispatch) is an open-source firmware system for commodity ESP32 and ESP8266 microcontrollers (under 5 per node) that combines a delay-tolerant two-tier RAM and LittleFS store-and-forward buffer, a multi-hop ESP-NOW mesh with hop-distance vector routing and probabilistic relay flood control, and an Active-Passive gateway election protocol that recovers from primary gateway failure without human intervention. Hardware evaluation on 3 physical nodes yields: direct-path packet delivery ratio of 98. 4% with median ACK latency of 2 ms (E1) ; 2-hop relay PDR of 88. 1% with a true relay overhead of 248. 7 ms over the direct-path baseline (E2) ; gateway election completing in approximately 4 s with full system recovery averaging 31, 393 ms across 3 trials (E3) ; and a 29. 3% reduction in relay broadcast count from the probabilistic gossip gate with no observed PDR impact (E4). Firmware, raw experimental logs, and data processing scripts are available at github. com/shakeelsaga/V. O. I. D at tag v2. 3. 0.
Shakeel Mohammed (Thu,) studied this question.