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Meshtastic ↔ Phone SMS/RCS Gateway

This project shows how off-grid mesh communication using Meshtastic can be extended to reach everyday mobile phones.

By bridging mesh messages to SMS and RCS, it enables communication between users in disconnected environments and those on standard cellular networks.

The user guide and GitHub repository below provide step-by-step instructions and source code for anyone interested in building or testing the system.

👉 User Guide

👉 Link to GitHub

Current Architecture and Design Documents

EmergencyHam Network (EHN) is an evolving architecture designed to enable resilient, identity-driven communication across multiple networks, including LoRa mesh systems, amateur radio, IP backhaul, and public endpoints such as SMS.

The documents below represent the current working design of the system. Together, they define how messages are structured, routed, governed, and delivered across heterogeneous networks while maintaining consistency and interoperability.

These are living documents. They are intended for:

  • technical review
  • community feedback
  • collaboration with operators, developers, and educators

Each document focuses on a specific layer of the system, but they are designed to work together as a unified, transport-agnostic architecture.

Start Here

EmergencyHam Network — High-Level Overview

A complete introduction to the EHN architecture

This document provides a top-level view of the entire system, including architecture, federation model, and core design principles.

It is the best place to start to understand:

  • how EHN works end-to-end
  • how identity, messaging, and routing interact
  • how the system operates in both connected and disconnected environments

👉 START HERE [Learn More / View Document]

Core Architecture Documents

EHN Directory Specification

Identity, endpoints, and resolution layer

Defines how users, roles, teams, devices, and services are represented within the network, and how identities are mapped to real-world endpoints.

Covers:

  • identity model (USER, ROLE, TEAM, SENSOR, NODE)
  • unique user_id concept
  • endpoint mapping and verification
  • policy-driven resolution

👉 [Learn More / View Document]

Emergency Message Protocol (EMP)

Message structure and communication standard

Defines the core message format used across all transports, ensuring consistent communication between systems.

Covers:

  • message frame structure
  • message types (TXT, CMD, ACK, TLM, etc.)
  • acknowledgments and retry behavior
  • Content Transparency & Compliance (CTC)

👉 [Learn More / View Document]

Full-Stack Concept Checklist

System-wide architecture and design model

Provides a consolidated view of the entire EHN architecture, connecting identity, messaging, routing, transport, and operations.

Covers:

  • layered system design
  • delivery semantics
  • priority and message handling
  • transport-agnostic operation

👉 [Learn More / View Document]

System Behavior & Operations

Control & Operations Specification

Runtime behavior of the system

Defines how messages move through the system in real time, including lifecycle, retries, and observability.

Covers:

  • message lifecycle states
  • retry and timeout logic
  • queueing and prioritization
  • operator control and audit logging

👉 [Learn More / View Document]

Routing & Path Selection Specification

How EHN chooses delivery paths

Defines how the system evaluates and selects routes across multiple networks.

Covers:

  • identity-first routing
  • path scoring (latency, trust, cost, availability)
  • failover and multi-path routing
  • policy-aware decision making

👉 [Learn More / View Document]

Transport Interface Specification

Standard interface for all network transports

Defines how different communication systems integrate into EHN through a common adapter model.

Covers:

  • transport adapter contract (send, listPaths, status)
  • path discovery and health reporting
  • phased routing evolution
  • multi-network support

👉 [Learn More / View Document]

Federation & Integration

Federation & Directory Synchronization Specification

How EHN scales across regions and gateways

Defines how identity and policy data are synchronized across distributed systems while maintaining operation during outages.

Covers:

  • gateway roles (full, edge, cache)
  • internet-based synchronization
  • offline operation and reconciliation
  • RF-based updates and roaming

👉 [Learn More / View Document]

Mode Compliance Matrix

Integration across existing communication systems

Evaluates how EHN integrates with existing technologies such as Meshtastic, APRS, Winlink, and SMS.

Covers:

  • what each system provides natively
  • what EHN must standardize
  • gateway responsibilities
  • interoperability considerations

👉 [Learn More / View Document]

Provisioning & UI Schema

Configuration and operator interface model

Defines how systems are configured and managed across different communication modes.

Covers:

  • identity and endpoint setup
  • policy and trust configuration
  • gateway settings
  • operator visibility and control

👉 [Learn More / View Document]

Scenarios & Validation

Scenario Pack

Real-world examples of EHN in operation

Demonstrates how the system behaves across different use cases, including emergency and routine scenarios.

Covers:

  • flood alert and emergency escalation
  • SMS-to-mesh communication
  • telemetry and low-bandwidth optimization
  • multi-path delivery behavior

👉 [Learn More / View Document]

Final Comments

EHN is an open, evolving architecture. These documents represent the current design and are intended to support collaboration, experimentation, and real-world deployment.

👉 Join us in building resilient communication systems for the future.