Integration with Winlink and APRS
The Complementary Stack
No single communications technology is sufficient for all emergency communications scenarios. The most resilient deployments combine multiple systems that complement each other's strengths. The three-layer stack of LoRa mesh plus Winlink plus APRS provides digital messaging, store-and-forward email, and position tracking - covering the primary data needs of an ICS-integrated emergency communications response.
Winlink Overview
Winlink is a worldwide radio email system that allows licensed amateur operators (and, under certain authorizations, non-amateur stations) to send and receive email messages via radio. Key components:
- Winlink Common Message Server (CMS): The cloud-based message store operated by the Winlink Development Team. Messages are held until retrieved by the recipient.
- Radio Message Server (RMS): A gateway station (typically a licensed operator's station with a TNC and radio) that provides radio access to the CMS. RMS gateways exist on HF (Pactor, VARA HF), VHF/UHF (Packet, VARA FM), and experimental LoRa modes.
- Client software: Winlink Express (Windows) or Pat Winlink (cross-platform, open source) are used by operators to compose messages and connect to RMS gateways.
Building a Winlink Gateway for ICS Form Delivery
A Winlink RMS gateway co-located with a mesh EOC node creates a powerful hybrid: field operators compose ICS 213 messages on a mesh-connected device, and those messages are forwarded to the EOC node which relays them into the Winlink system for delivery to served agency email addresses.
Hardware Required for a VHF/VARA FM Gateway
- VHF FM transceiver (e.g., Icom IC-7100, Kenwood TM-D710)
- Sound card interface or VARA FM modem (e.g., Digirig Mobile)
- Windows PC or Raspberry Pi running Winlink Express or Pat
- Internet connection to CMS (for a full gateway); or peer-to-peer mode for offline operation
Configuration Steps (VARA FM)
- Install VARA FM modem software and configure audio levels to the transceiver.
- Install Winlink Express. Configure station call sign, grid square, and VARA FM as the primary radio mode.
- Enable RMS Relay mode in Winlink Express to accept connections from client stations.
- Register the gateway with the Winlink network (requires licensed callsign and internet access at least once for initial registration).
- Test by connecting with a second station using Pat or Winlink Express in client mode.
ICS 213 forms composed in Winlink Express are transmitted as structured email attachments. Served agencies with standard email can receive these forms without any special software.
APRS as a Parallel Position Tracking Layer
Automatic Packet Reporting System (APRS) operates on 144.390 MHz (North America) and provides real-time position reporting, weather data, and short messaging via a nationwide network of digipeaters and I-gates (internet gateways). APRS complements Meshtastic mesh in the following ways:
| Feature | Meshtastic Mesh | APRS |
|---|---|---|
| Position tracking | Yes (GPS, within mesh coverage) | Yes (GPS, nationwide via digipeaters) |
| Text messaging | Yes (encrypted, multi-hop) | Limited (unencrypted, short messages) |
| Internet connectivity required | No (self-contained mesh) | No for local; yes for APRS-IS |
| License required | No (ISM band) | Yes (Technician or higher) |
| Nationwide coverage | Only where mesh nodes exist | Yes (existing infrastructure) |
| Typical range per hop | 2-15 km | 10-100 km via digipeater |
A field operator equipped with both a Meshtastic device and a VHF APRS tracker (e.g., Mobilinkd TNC with a handheld radio, or a Kenwood TH-D74) provides redundant position visibility: the EOC can track them on the local mesh map AND on aprs.fi via APRS-IS.
Mesh + Winlink + APRS: The Complete Stack
When all three systems are operational, the complementary roles are:
- LoRa Mesh (Meshtastic): Short-range encrypted text messaging, welfare check-ins, ICS 213 relay within the incident area, GPS position sharing among mesh-equipped operators.
- Winlink: Store-and-forward email delivery for ICS forms to served agency recipients, long-haul message delivery via HF when VHF infrastructure is unavailable, formal record of messages (timestamped, archived).
- APRS: Nationwide position tracking for mobile operators outside mesh coverage, real-time map display on aprs.fi for remote coordination, weather object broadcasting.
Tools and Software
| Tool | Platform | Purpose |
|---|---|---|
| Meshtastic app | iOS / Android / Web | Mesh node control, messaging, map view |
| Winlink Express | Windows | Winlink client and gateway software; ICS form templates included |
| Pat Winlink | Linux / macOS / Windows / Raspberry Pi | Open-source Winlink client; CLI and web UI; ideal for headless gateway builds |
| Direwolf | Linux / Windows | Software TNC for APRS and Winlink Packet; runs on Raspberry Pi |
| YAAC / APRSdroid | Java (desktop) / Android | APRS client for tracking and messaging |
| atak-forwarder | Android (ATAK plugin) | Forwards Meshtastic positions into ATAK/WinTAK for ICS TAK server integration |
Practical Integration Workflow
- Pre-event: Configure all mesh nodes on the agreed channel. Pre-load ICS 213 message templates on devices used by served agency liaisons.
- At EOC: Stand up Winlink gateway on VHF. Confirm Pat or Winlink Express can reach a CMS. Test ICS 213 form delivery to served agency email.
- At EOC: Enable APRS I-gate (via Direwolf and VHF radio) to provide internet-visible position tracking for all APRS-equipped operators.
- Operations: Field operators use Meshtastic for local comms. When a message must reach a served agency email (hospital, county OES), it is forwarded to the EOC mesh node and injected into Winlink for delivery.
- Position tracking: EOC staff monitor both the Meshtastic map (local, encrypted) and aprs.fi (wide area) to maintain situational awareness of all resources.