One dedicated server-radio device.
A Trail-compatible LoRa device participates in the radio network and connects to the Linux server through the simulator-tested LUSR/1 USB contract. Hardware and firmware compatibility remain unproven.
Trail project / Linux server and LoRa gateway
Limited Underground Trail Server
A planned Linux server appliance with its own dedicated Trail-compatible LoRa device, a LAN administration interface, geographic storage, and bounded large-file delivery.
Clean VM reproduction and bounded API scaffold verified - reserved LAN and live radio pendingEvidence updated August 29, 2026Work in progress
Overview
A server that joins the Trail radio network through its own device.
The accepted provisional direction reuses established server infrastructure while keeping the Trail-specific radio boundary explicit.
One dashboard, locally and across the LAN.
A minimal graphical session opens the administration interface on the server. Other authorized local-network machines can reach the same interface by IP.
Use IP delivery where LoRa is the wrong transport.
The server can publish digest-bound manifests and provide separately supported downloads for firmware, map packages, or other files that do not belong on the radio network.
Roadmap
Build the smallest functional Linux appliance first.
Architecture, the first host profile, and the local server-radio contract are selected; clean VM reproduction, the bounded API scaffold, and host-side contract simulation passed, while reserved-LAN and hardware acceptance remain open.
Current foundationAccepted direction
Server Option V0
Debian 13.6.0, ASP.NET Core, PostgreSQL/PostGIS, Caddy, MapLibre/PMTiles, and one dedicated USB-connected Trail LoRa device.
- Web access
- Local browser plus LAN access by reserved server IPv4 address
- First transport
- Plain HTTP on the trusted LAN; trusted HTTPS is deferred
- Evidence today
- Clean Debian VM reproduction, post-reboot host verification, bounded .NET 8 API, and twelve LUSR/1 host-simulator cases passed; hardware radio, database, and final LAN acceptance remain open
First functional serverHost profile in progress
Debian host and live server radio
Reproducible installation, persistent queues, live receive/transmit processing, LAN dashboard access, database recovery, and one exact dedicated server-radio binding.
- Hardware
- No supported server-radio target selected
- Deployment
- Debian 13.6.0 amd64 clean VM passed install, provision, reboot, kiosk, and full verifier
- Acceptance
- Software-host reproduction and temporary-NAT checks passed; reserved physical-LAN and second-machine acceptance remain open
Capabilities
A useful prototype, not a working server.
The current repository provides a concrete interface direction, public architecture records, and a reproducible host-profile starting point.
Interactive administration-interface prototype.
Demonstration screens cover operations, people, devices, communications, locations, alerts, readiness, updates, backups, and server settings.
Reusable infrastructure is selected.
Established Linux, web, database, geographic, file-delivery, and map components avoid creating generic infrastructure from scratch.
No live radio, database, or final-LAN deployment.
The bounded service reports operational false and radio unavailable. Its LUSR/1 worker is disabled by default and has no serial or USB transport, hardware connection, persistent queue, or durable receive authority.
Components
Clear boundaries keep the server replaceable.
Each reusable component has one job; Trail-specific behavior remains inside explicit project code and contracts.
Dedicated Trail-compatible LoRa device over USB.
Owns radio participation, packet protection, and a bounded host interface.
Modular server, persistent queues, and administration.
Processes validated radio events, schedules outbound traffic, stores history, and exposes operator workflows.
LAN dashboard, maps, and large files.
Kept separate from the LoRa link so large content and administration do not distort the radio protocol.
Technology
Reuse proven infrastructure; build only the Trail-specific layer.
Option V0 is provisional and individual components may change after implementation evidence.
Debian 13.6.0 host profile
- Local interface
- LightDM, Openbox, and Chromium kiosk on loopback
- LAN interface
- Dashboard by reserved IPv4 address; SSH and HTTP only from the configured LAN
- Status
- Clean Hyper-V reproduction passed; reserved physical-LAN and second-machine acceptance remain pending
ASP.NET Core
- Reuse
- Web APIs, background services, health checks, configuration, authentication, and administration UI foundation
- Custom work
- USB gateway, Trail queues, processing rules, manifests, and operator workflows
- Status
- Phase A health/configuration deployment passed; the disabled-by-default Phase B LUSR/1 worker passed eleven lifecycle simulator cases with no serial, USB, TX, or RX acknowledgement authority
LUSR/1 over USB
- Boundary
- Versioned COBS framing, canonical CBOR, logical identity, bounded credits, and opaque on-air payloads
- Recovery
- Idempotent transmit IDs, durable receive-before-ack, reconnect reconciliation, and explicit reboot uncertainty
- Status
- Twelve compact .NET 8 simulator cases passed; no Heltec, USB device, firmware, or RF link was tested
PostgreSQL and PostGIS
- Records
- Messages, alerts, devices, radio observations, delivery queues, and audit history
- Geography
- Locations, tracks, proximity, spatial indexes, and later geofencing
- Status
- No schema or migration exists
Caddy, MapLibre, and PMTiles
- Caddy
- LAN reverse proxy, static files, HTTP range requests, and later TLS
- MapLibre
- Map rendering for the local and LAN dashboard
- PMTiles
- Packaged basemaps and bounded large map archives
Development status
Foundation, bounded service, and local bridge lifecycle verified.
The verified host, API, contract, and hardware-free bridge remain limited development milestones, not an operational Trail Server or a completed deployment.
Option V0 and LUSR/1 accepted.
The public record captures the Linux, LAN, dedicated-radio, storage, map, and large-file boundaries plus the simulator-tested local USB contract.
Standalone public project foundation.
Architecture, status, decisions, backlog, interface prototype, host-profile assets, and the bounded .NET 8 service scaffold are organized independently from OpenTrail firmware and Android work.
Verify the final reserved-LAN boundary.
Assign the private router reservation, then prove HTTP and SSH access plus bounded blocked-port denial from a second machine on that LAN.
Documentation
Read the current architecture and its limits.
The repository is the authority for Trail Server decisions and implementation status.
ArchitectureSystem boundary, reusable components, and deferred choices.Linux host profileExact Debian seed, kiosk, LAN, firewall, recovery, and reproduction gate.Server-radio USB contractLUSR/1 framing, identity, queue, recovery, and privacy boundaries.Project statusCurrent evidence and everything not yet implemented.BacklogOrdered gates from foundation through one dedicated server-radio device.
GitHub repository
The public Trail Server project.
Follow the architecture, interface prototype, decisions, validation, and future implementation.
Limited Underground Trail Server on GitHub
The repository now contains architecture, interface-prototype, host-profile evidence, a bounded non-operational service scaffold, and a disabled hardware-free radio bridge. It does not contain a functional or supported server release.
Contribute
Improve the reusable foundation without overstating it.
Useful early contributions focus on Linux deployment, USB recovery, geographic storage, accessibility, and bounded protocol review.
Reproducible appliance and USB reliability.
Help test the selected Debian profile, service recovery, stable device paths, and local-network access.
Persistence, queues, and failure recovery.
Review migrations, idempotency, bounded retries, backups, and restoration behavior.
Accessible local operations.
Improve the administration prototype while keeping demonstration data and unavailable functions visibly labeled.