Meshtastic & MeshCore — Off-Grid Text Mesh

What Is Meshtastic?

Meshtastic turns cheap LoRa radio modules into a decentralized, encrypted text mesh network. Every node automatically relays messages for other nodes. No cell towers. No internet. No license required.

Think of it as group texting that works when everything else is down. Send text messages and GPS positions over miles of range, completely off-grid.

Cost to Start
~$50
Two nodes (T-Beam Supreme) + batteries
License Required
NONE
915 MHz ISM band — FCC Part 15, license-free
Range (over water)
5-30+ miles
Puget Sound is ideal — water = near-zero signal loss
Range (forest)
1-5 miles
PNW tree canopy absorbs signal — elevation helps enormously

How It Works

Every Meshtastic node is both a radio and a relay. When you send a message:

You send "Need water at Zone 3" → Your node transmits on 915 MHz → Neighbor's node receives it, rebroadcasts it → Next node receives, rebroadcasts again → Message reaches someone 10 miles away through 3 hops → If any node has MQTT internet gateway, message goes global

Default hop limit is 3 (can be raised to 7). Each hop adds 1-5 seconds of latency. A message crossing 20 miles through 4 hops takes about 10-20 seconds.

Anderson Island Mesh Vision

The Plan: One Tower to Cover the Island and Beyond

A single high-power relay node at the center of Anderson Island, with an antenna above the treeline (~80 ft mast at ~300 ft elevation = ~380 ft effective height), would:

  • Cover the entire island — every zone, every neighborhood
  • Reach Steilacoom (3 miles across water — easy)
  • Reach Tacoma (10 miles — line of sight over water)
  • Reach Olympia (20 miles — over-water shot via South Sound)
  • Reach Key Peninsula, Vashon, Fox Island (5-15 miles)
  • Connect to mainland mesh nodes on Tiger Mountain, Gold Mountain, Capitol Peak
  • Bridge the entire island to the regional Puget Sound mesh network

How Far Can a Message Go?

Anderson Island (your node) │ ├─ 3 mi ──→ Steilacoom (direct, over water) │ └─→ Lakewood / JBLM area │ ├─ 10 mi ─→ Tacoma (over water, line of sight) │ └─→ Tiger Mountain relay (40+ mi coverage) │ └─→ Seattle metro mesh (hundreds of nodes) │ └─→ MQTT gateway → GLOBAL │ ├─ 15 mi ─→ Vashon Island │ └─→ West Seattle / Fauntleroy │ ├─ 8 mi ──→ Key Peninsula / Gig Harbor │ └─→ Kitsap mesh (Gold Mountain relay) │ └─→ Bremerton / Bainbridge │ └─ 20 mi ─→ Olympia area (Capitol Peak relay) └─→ Thurston County mesh └─→ South toward Centralia/Chehalis With MQTT gateway: Anderson Island → Internet → ANY Meshtastic node worldwide Typical latency: 2-5 seconds per hop, 10-30 seconds for multi-hop
Without MQTT (pure radio mesh)

Messages can travel as far as the mesh extends — typically 50-100+ miles through relay chains in developed mesh areas. The PNW mesh is growing fast. With the right relay nodes on hilltops, Anderson Island to Portland (~130 mi) is achievable through 5-8 hops.

With MQTT (internet gateway)

If ANY node in the chain has internet and an MQTT gateway enabled, your message reaches the global Meshtastic MQTT server and can be received by any Meshtastic user worldwide who's connected to the same channel. This is how off-grid meets global. Even one internet-connected node in Tacoma makes your Anderson Island message worldwide.

Get Started — 5 Steps

1
Buy 2 Nodes
Recommended: LilyGo T-Beam Supreme (~$45 each)
Also need: 2x 18650 batteries (Samsung 30Q), 2x 915MHz antennas
Total: ~$110-130 for a pair
2
Flash Firmware
Go to flasher.meshtastic.org in Chrome. Plug in via USB. Click flash. Done in 60 seconds.
3
Install the App
Download Meshtastic from Google Play or App Store (free). Connect via Bluetooth.
4
Configure
Region: US | Modem: LONG_FAST | Channel: Leave LongFast default
This puts you on the public discovery channel where all Meshtastic users can see each other.
5
Add a Private Channel
Settings → Channels → Add → Name it (e.g. "AI-EMCOMM") → Generate encryption key → Share QR code with your team in person.

Building the Anderson Island Tower Node

A permanently mounted, solar-powered relay node at the highest central point of the island. This is the backbone of the island mesh.

Hardware — The "Beefy" Build

ComponentRecommendationCostWhy
Radio BoardRAK WisBlock 4631 + 19007 baseboard$35Best battery life, designed for solar outdoor nodes
AntennaRokland 5.8 dBi fiberglass omni, N-female$40High-gain omnidirectional, weatherproof, covers 360°
CoaxLMR-400 cable, N-male to SMA pigtail$30-50Low-loss for long cable runs to mast top. CRITICAL — cheap coax kills your signal.
MastSteel push-up mast or guyed aluminum (60-80 ft)$200-800Gets antenna above treeline. Height is everything.
Solar Panel10W 6V panel (or 20W for PNW winter reliability)$30-50Must sustain through Nov-Feb cloudy weeks
Battery3.7V 10,000-20,000 mAh LiPo$20-40Needs 5-7 days of reserve for PNW winter dark stretches
EnclosureIP67 ABS junction box, 8x6x4"$12Weatherproof, vented for heat
Lightning ProtectionPolyPhaser or similar coax surge protector$50-80Tallest antenna on the island = lightning rod. PROTECT IT.
Grounding8ft copper ground rod + #6 AWG copper wire$30Required for lightning protection
Total$450-1,100Depending on mast height and quality

Configuration for Tower Node

SettingValueWhy
RoleROUTERDisables screen, minimizes power, maximizes relay duty
RegionUS915 MHz ISM band
ModemLONG_FASTBest range/speed balance
TX Power30 dBm (1 Watt)Maximum legal power on 915 MHz ISM
GPSDisabled (set fixed position)Saves significant power — node doesn't move
Hop Limit5-7Allow messages to traverse longer chains
Power SavingEnabledEssential for solar operation
MQTTEnabled if internet availableBridges local mesh to global network

Why Antenna Height Matters

Height vs. Range (over water, LONG_FAST, 1W): Ground level (6 ft): 3-5 miles Roof mount (25 ft): 8-15 miles 40 ft mast: 15-25 miles 60 ft mast: 20-35 miles 80 ft mast (380 ft ASL): 30-50+ miles ← YOUR TARGET Radio horizon formula: d(miles) = 1.23 × √h(feet) At 380 ft ASL: 1.23 × √380 = ~24 miles to radio horizon With elevated receiving station (100ft): add ~12 mi = 36 miles Over water bonus (smooth reflective surface): +20-50% Effective range: 35-50+ miles to elevated stations
With an 80 ft mast at the center of Anderson Island...

Your radio horizon is ~28 miles. Any Meshtastic node within that radius — on the water, on a roof, in a car — can reach you directly. That covers Tacoma, Olympia, the entire Key Peninsula, Vashon, Fox Island, and parts of Seattle. You become the relay hub for the entire South Puget Sound mesh.

Legal Limits

Max TX Power1 Watt (30 dBm) — FCC Part 15.247 for 915 MHz spread spectrum
Max EIRP4 Watts (36 dBm) — transmitter power + antenna gain combined
Antenna Gain LimitWith 1W TX: max ~6 dBi antenna gain to stay under 4W EIRP
LicenseNone required — ISM band, Part 15
EncryptionAllowed — Meshtastic uses AES-256 by default

MeshCore — Store-and-Forward Alternative

MeshCore is separate firmware for the same LoRa hardware. Key difference: messages are stored at relay nodes and forwarded when recipients come in range.

Meshtastic vs MeshCore

FeatureMeshtasticMeshCore
RoutingFlood (every node rebroadcasts)Managed routing with distinct roles
Node TypesAll roughly equalRoom nodes (servers), Repeaters, Companions (clients)
EncryptionPSK per channelPer-contact end-to-end (like Signal)
MessagesIn transit only — if no one hears it, it's goneStored at Room nodes, forwarded later
Community SizeLarge, mature, many nodes in PNWSmaller, growing
Best ForReal-time mesh, discovery, communitySparse networks, guaranteed delivery
Interoperable?NO — MeshCore and Meshtastic cannot talk to each other

Recommendation for Anderson Island

Run Both

Primary: Meshtastic — larger community, more relay nodes, better for real-time emergency comms during an event.

Secondary: MeshCore Room node at the tower — acts as a message board. People check in, leave messages, come back later to read replies. Perfect for post-earthquake coordination when not everyone is awake/available at the same time.

Same hardware, different firmware. Buy extra nodes — flash some Meshtastic, some MeshCore.

Get Involved

For the Anderson Island Community

1
Buy a node and join the mesh — Even one node on your roof extends the network for everyone.
2
Check into the Wednesday night AI ARC Net — 7pm on 147.300 MHz (tone 88.5). Meet the radio community.
Need a radio? →
3
Join Anderson Island Preparestogether@aiprep.us or aiprep.us/get-involved
4
Join the Emergency Communications Groupandersonislandecg.org — they maintain the island's GMRS and HAM infrastructure.
5
Get your GMRS license — $35, no exam, covers your whole family. This is the backbone of the AI Prepares coordinator network.
Recommended GMRS radio:
6
Get your HAM Technician license — Study at hamstudy.org, take the exam online. 2 weeks of study.
Starter radio: +

Resources

Meshtasticmeshtastic.org — firmware, docs, community
Flash Firmwareflasher.meshtastic.org — web-based flasher
Live Mesh Mapmeshmap.net — see active nodes near you
MeshCoreSearch "MeshCore firmware" on GitHub
AI Preparesaiprep.us — Anderson Island disaster preparedness
AI ECGandersonislandecg.org — emergency communications group
PNW Meshtastic CommunitySearch "PNW Meshtastic" on Discord and Reddit
Ham Studyhamstudy.org — free license exam prep

The Puget Sound Mesh Network

The Puget Sound corridor is one of the densest Meshtastic meshes in the US — estimated 500-1,500+ active nodes along the I-5 corridor from Olympia to Bellingham, roughly doubling every 6 months.

Known High-Site Relay Locations

LocationElevationCoverage
Tiger Mountain (Issaquah)3,004 ftSeattle metro, east to Snoqualmie — critical relay hub
Capitol Peak (Olympia)2,658 ftSouth Sound, Olympia basin
Gold Mountain (Bremerton)1,761 ftKitsap Peninsula, Bainbridge, cross-sound links
Cougar Mountain (Bellevue)1,595 ftEastside Seattle, overlaps Tiger
Queen Anne / Capitol Hill~500 ft + buildingsCentral Seattle rooftop nodes

How Far Can You Actually Reach?

Destination from AIDistanceHopsLatencyFeasibility
Steilacoom3 mi1 (direct)2-5 secEasy
Tacoma10 mi1-25-10 secEasy with tower
Key Peninsula / Gig Harbor8-12 mi1-25-10 secGood over water
Vashon Island15 mi1-25-15 secOver-water shot
Olympia20 mi2-310-20 secNeeds Capitol Peak relay
Seattle35 mi3-515-30 secVia Tiger Mtn relay chain
Portland130 mi5-830-60 secNeeds relay chain through Chehalis gap
East of Cascades100+ miN/AN/ACascades block RF — MQTT only
Anywhere (via MQTT)Global1 hop to gateway1-5 secIf any node has internet

MQTT Gateway — Local Mesh Goes Global

If your tower node has internet (WiFi or Starlink), it becomes an MQTT gateway — every message hitting your node bridges to the internet and can reach the entire world.

How It Works

Someone on Anderson Island sends a mesh message → Your tower node receives it via radio → MQTT bridge forwards to mqtt.meshtastic.org (or your own MQTT server) → Any Meshtastic user worldwide on the same channel receives it → Your VPS can subscribe and trigger alerts (Telegram, RocketChat, etc.) → Messages from the internet can come BACK down to the mesh via your gateway
What This Means for Anderson Island

With one internet-connected MQTT node on the island, you get:

  • Every mesh message backed up to the cloud — nothing gets lost
  • Telegram alerts — mesh messages forwarded to your phone
  • Global reach — messages from people with no internet reach people anywhere
  • Remote monitoring — see node health and mesh traffic from anywhere

Even during a Cascadia earthquake, if Starlink stays up (satellite = no ground infrastructure), your MQTT bridge keeps Anderson Island connected to the world.

Live Mesh Map

See active Meshtastic nodes near Anderson Island. Nodes that opt into position reporting show up here.

Open Live Mesh Map (meshmap.net)

Opens in new tab — centered on Anderson Island. Requires internet.

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