How Blackout Comms Coverage Works
Blackout Comms is a private LoRa mesh. Trusted devices form a cluster, text, share location, and hold messages (up to 24 hours for DMs) even if the recipient is out of range or powered off. Direct neighbors get instant delivery; everything else uses multi-hop meshing with smart path planning and a decentralized cache.
Line of Sight & Elevation
LoRa loves clear paths. If you can see the other antenna (or nearly can), range is best. Hills, dense trees, and buildings block or weaken signals. Raising an antenna (rooftop, tower, or just higher ground) often makes a dramatic difference because it clears nearby obstacles and improves the Fresnel zone.
This planner samples elevation around each device. When your effective height (ground + antenna) has a clear advantage over nearby terrain, it can apply a user-adjustable boost to the displayed coverage circle. Treat the boost as optimistic guidance—always verify in the field.
Antenna Choices
- Stock / small antennas — Fine for short range or handheld use. Keep them vertical.
- Better external antennas (omni or directional) — Higher gain and better placement dramatically improve range. Mount them as high and clear as practical.
- Height > gain in many real situations. A modest antenna high up often beats a fancy one low and obstructed.
- Polarization should match (usually vertical). Keep coax short or use low-loss cable.
Amplifiers
Stock Blackout Comms devices transmit around 0.2 W. A 1 W amp (legal in many regions without a license) can help punch through light obstacles and extend range. Higher power (e.g., 20 W) requires an amateur radio license in most places and can produce very long single-hop distances with good LOS (tens of km have been demonstrated).
Amps increase power draw and can create more interference if not used carefully. Place them on links that stay powered (solar is common). Always follow local regulations.
Rural vs Urban
- Rural / open — Excellent potential. With decent LOS and height you can routinely see 4–5+ miles per hop without amps; amps and good antennas push much farther. Fewer buildings and less RF noise.
- Urban / suburban — Buildings, trees, and interference reduce range. Expect shorter hops. Mesh helps by routing around obstacles, but place links high (roofs, hills) and closer together. Light walls and foliage are penetrable to a limited degree; solid concrete and metal are not.
LoRa Characteristics
LoRa uses spread-spectrum modulation that is relatively good at penetrating light obstacles (trees, light vegetation, some walls) compared with higher-frequency systems, but it is not magic. Dense forest, multiple walls, or metal structures will still stop it. Frequency hopping (unique to each Blackout Comms cluster) improves resistance to interference and jamming and can help reliability.
Mesh is often more important than pure single-hop distance. Well-placed always-on links act as relays and packet caches, extending both range and time (messages can wait for a device that is currently off or out of range).
Practical Planning Tips
- Use this tool to place links on high ground or rooftops with good views of the areas you care about.
- Handhelds (T-Deck, etc.) are mobile; their coverage is temporary. Links should stay powered and elevated.
- Start with the default 2-mile circles, then raise height or enable the LOS boost for elevated sites. Test real RSSI and delivery in the field.
- Overlapping coverage and multiple paths make the mesh more reliable.
- For very long distances, consider MQTT bridges (when any internet exists) or carefully planned high-power links.
Ranges vary widely with terrain, antennas, power, weather, and interference. This planner is a layout aid, not a guarantee. Always follow local radio regulations.
Click the map to add Links or Handhelds.