ESP32-S3-DevKit LiPo Rev B

CASTOR

Communication and Autonomous System for Tactical Operations & Rescue

Problem - Natural disasters can rapidly disable communication infrastructure, leaving affected communities and emergency responders unable to communicate

Goal - Develop a portable, infrastructure-independent emergency communication network that allows people and responders to exchange critical information even when cellular and internet networks are unavailable.

Core Concept

Castor links multiple independent, decentralized nodes over long-range radio frequencies. Every individual node acts as an active repeating router that can autonomously perform seven primary tasks:

• Receive packets from adjacent nodes
• Transmit self-generated payloads
• Forward external packets through the mesh
• Detect and drop duplicate traffic
• Decrease packet Time-to-Live (TTL) values
• Generate new localized telemetry or text data
• Connect nearby civilian devices through localized Wi-Fi portals

Hardware Architecture

Each network node is constructed using commercial off-the-shelf hardware, ensuring low assembly costs and high deployability:

• Microcontroller: ESP32-S3 (Manages system logic, packet parsing, and web interface)
• LoRa Module: Waveshare Core1262-868M (Handles long-range, low-power radio communication)
• Antenna: High-gain 915Mhz tuned antenna
• Power Source: Independent battery array / solar backup
• Access Layer: Integrated 2.4GHz Wi-Fi access point for localized user discovery

Network Routing & Mitigation Mechanics

Time To Live (TTL)

To prevent infinite routing loops that saturate the airwaves, every packet drops its TTL value by 1 at every node jump. Once TTL is 0, the packet is dropped.

Duplicate Packet Detection

Because mesh topologies naturally create multi-path echoes, a node can receive the exact same packet from different neighboring vectors.

Every node retains a rolling lookup Packet Cache tracking the unique identifier signature, being the source ID + the packet's random ID