Radio & Mesh Networks

When the internet dies—censorship, blackout, infrastructure collapse—the ability to communicate doesn't have to die with it. Radio waves don't need fiber cables, cell towers, or ISP accounts. They travel through walls, across valleys, over mountains. This is the knowledge of building communication networks that work when everything else fails.

The Spectrum: Understanding Radio

Radio is electromagnetic radiation, just like light but at frequencies our eyes can't see. Different frequencies have different properties—some penetrate buildings, some bounce off the ionosphere, some require line-of-sight.

Frequency Bands (Practical Overview)

AM/FM Broadcast (530 kHz - 108 MHz):

AM (530-1700 kHz): Long range, especially at night, susceptible to interference
FM (88-108 MHz): Higher quality, shorter range, less interference
Uses: Receiving emergency broadcasts, news when internet is down

Citizens Band (CB) Radio (26.965-27.405 MHz):

40 channels, no license required (US)
Range: 1-10 miles depending on conditions
Uses: Local coordination, trucker networks, emergency communication

Family Radio Service (FRS) (462-467 MHz):

No license required (US)
Limited power (0.5-2 watts), short range (1-2 miles)
Uses: Family/hiking communication, neighborhood networks

General Mobile Radio Service (GMRS) (462-467 MHz):

License required (no test, just fee, covers family)
Higher power (5-50 watts), repeater access
Range: 5-25 miles with repeaters
Uses: Neighborhood watch, community coordination, regional nets

Amateur Radio (Ham) (Multiple bands):

Technician class: VHF/UHF (2m, 70cm bands)
General/Extra class: HF (shortwave, global range)
Uses: Emergency communication, long-distance contacts, technical experimentation

LoRa (Long Range) (433/868/915 MHz):

Low power, long range (miles), low bandwidth
Uses: Mesh networks, IoT, off-grid messaging

WiFi (2.4/5 GHz):

High bandwidth, short range, line-of-sight challenged
Modified/adapted for mesh networking

Getting Started: Unlicensed Options

You don't need a license to start building resilient communications.

CB Radio

Equipment:

Handheld units: $30-80
Mobile/base units: $50-200
Antennas: $20-100 (magnet mount for vehicles, base station for home)

Range:

Handheld: 1-3 miles
Mobile with good antenna: 5-15 miles
Conditions matter: elevation, obstacles, atmospheric conditions

Channels:

Channel 9: Emergency (monitored by REACT and some emergency services)
Channel 19: Truckers/road info
Channel 17: North-South traffic
Channel 14: General use
Channel 3: Prepper network (unofficial)

Legal considerations:

Power limit: 4 watts AM, 12 watts PEP SSB
No license required
No modified amplifiers (illegal)
Keep it clean (FCC enforces obscenity rules)

FRS/GMRS Radios

Popular models: Baofeng UV-5R (requires license for GMRS frequencies), Motorola Talkabout, Midland radios

FRS (no license):

Channels 1-7 (shared with GMRS, low power)
Channels 8-14 (FRS only)
Simple, immediate use

GMRS (license required):

Channels 15-22 (higher power allowed)
Repeater channels (requires tone/offset programming)
License: $35 for 10 years, covers immediate family

Advantages:

Compact, portable
Clearer than CB
More private (not monitored like CB)
Easy to use

Mesh Networks: The Digital Underground

When internet infrastructure fails but you still need digital communication—file sharing, messaging, web services—mesh networks step in.

What is a Mesh?

Traditional networks: Central hub (router/cell tower) connects all devices. If hub dies, network dies.

Mesh networks: Every device connects to multiple neighbors. If one node fails, traffic routes around it. No central point of failure.

Meshtastic: The Off-Grid Messenger

What it is: Open-source firmware for cheap LoRa radios that creates an encrypted, off-grid messaging network.

Hardware:

TTGO T-Beam: ~$30, GPS, display, battery
Heltec LoRa 32: ~$20, basic mesh node
Rak Wireless WisBlock: Modular, professional

Features:

Text messaging (no infrastructure needed)
GPS location sharing
Encrypted channels
Range: miles between nodes, potentially regional with enough nodes
Solar-powered nodes run indefinitely

Use cases:

Neighborhood communication
Hiking group coordination
Emergency messaging when cell towers fail
Protest communication (no central infrastructure to seize)
Rural areas without cell coverage

Setup:

Flash Meshtastic firmware to ESP32-based LoRa board
Configure via Bluetooth app or serial
Set channel encryption (critical)
Deploy nodes with power (USB, battery, solar)
Messages hop from node to node until they reach destination

Limitations:

Low bandwidth (text only, no images/voice)
Range depends on terrain and node density
Requires multiple nodes for regional coverage
900MHz (US) has power limits

Reticulum: The Network for Resilience

What it is: A networking protocol designed specifically for resilience—works over any transport (LoRa, packet radio, WiFi, ethernet, even paper).

Philosophy: If you can send data by any means, Reticulum can route it. It handles the complexity of multiple transport types automatically.

Use with:

LoRa radios (low-bandwidth, long-range)
Packet radio (ham bands)
Standard internet (when available)
Sneakernet (physical media transport)

Features:

Automatic routing around failures
End-to-end encryption
Identity system
File transfer
Remote command execution
Works when internet is down

Status: Active development, early adoption phase

WiFi Mesh: For When Power and Equipment Exist

Commercial: Eero, Netgear Orbi, Ubiquiti UniFi

DIY/Open Source:

batman-adv: Linux mesh networking kernel module
openwrt: Router firmware with mesh support
libremesh: Community mesh firmware

Setup:

Flash OpenWrt to compatible routers
Configure mesh interface
Deploy nodes with power and line-of-sight where possible
Internet gateway optional (local mesh works without it)

Use cases:

Apartment building networks
Neighborhood internet sharing
Temporary event networks
Disaster recovery (quick deployment)

Limitations:

Requires power (AC or substantial battery/solar)
Range limited by WiFi propagation (buildings, terrain)
Higher power consumption than LoRa

Packet Radio: The Digital Ham

What it is: Sending digital data (text, files, images) over amateur radio frequencies.

Requirements: Amateur radio license (Technician class minimum)

Equipment:

Radio: Baofeng UV-5R (~$25), Yaesu, Icom, Kenwood
Interface: Signalink USB (~$120), or homemade cable
Software: Dire Wolf (TNC), VARA (modem), Winlink (email)

Modes:

Packet (AX.25): Original digital mode, slow but reliable
Pactor: Faster, proprietary but standard for Winlink
VARA: Modern, fast, efficient, software-based
APRS: Automatic Position Reporting System, location/messaging

Winlink: Radio email system

Send/receive email over HF/VHF/UHF
No internet required
Gateway stations connect to internet when available
Used by emergency services, boats, remote areas

Use cases:

Email when internet is down
Emergency communication infrastructure
Remote monitoring (weather stations, etc.)
Long-distance digital communication

Learning path:

Get Technician license (easy test, $35 exam fee)
Buy VHF/UHF radio (2m/70cm)
Build/buy interface cable
Install software, configure
Join local packet network

Going Licensed: Amateur Radio

If you're serious about off-grid communication, get your ham license.

The License Classes

Technician:

Entry level
VHF/UHF privileges (line-of-sight, local/regional)
Some HF privileges (limited)
Test: 35 questions, multiple choice
Study: 1-2 weeks of evening study
Cost: ~$15 exam fee

General:

Full HF privileges (shortwave, global communication)
The real reason to get licensed
Test: 35 questions
Requires Technician first

Extra:

Full spectrum privileges
Extra test questions
Vanity call signs
Not essential for most purposes

Why Bother?

Legal transmit power: Unlicensed devices (FRS, CB) are limited to milliwatts to watts. Ham radio allows 50-1500 watts legally.

Access to infrastructure: Repeaters, networks, emergency organizations.

Knowledge community: Hams are technical, self-reliant, and often share knowledge.

Emergency privileges: When declared emergency, hams can operate outside normal bands (if necessary).

Getting Licensed

Study resources:

HamStudy.org (free/paid, excellent)
ARRL study guides
YouTube: Ham Radio Crash Course
Practice tests until consistently passing

Finding exams:

ARRL website exam search
HamStudy exam finder
Local ham clubs (often free testing)

Equipment after license:

Handheld: Baofeng UV-5R ($25) - technically requires Part 90 for GMRS, but widely used
Mobile: Yaesu FT-2980R ($150), any 2m mobile
Base: Various options $200+
Antennas: DIY copper J-pole ($10 in parts), commercial antennas

Building Antennas

Antennas are critical—often more important than radio. Good antennas are cheap to build.

The J-Pole (2m/70cm)

Materials: Copper pipe, fittings, SO-239 connector Construction: 3/4 wavelength radiating element, 1/4 wavelength matching section Performance: Omnidirectional, low angle radiation (good for distance), easy to build Cost: ~$10-15

The Dipole

Materials: Wire, insulators, balun (optional), coax Formula: Length (feet) = 468 / frequency (MHz)

2m band (146 MHz): ~3.2 feet total
70cm band (446 MHz): ~1 foot total

Construction: Center insulator, two equal legs, end insulators, hung horizontally or inverted V

Directional Antennas

Yagi: Directional, high gain, requires pointing

Materials: PVC pipe, aluminum rods, coax
Performance: 5-15 dB gain (significant range extension)
Use: Fixed direction links, emergency communication beams

Moxon: Simpler directional, smaller than Yagi

Good for emergency use
Easier to build and tune

Feedline

Coaxial cable: Carries signal from radio to antenna

RG-58: Lossy, cheap, only for short runs
RG-8X: Better, good for mobile
LMR-400: Low loss, expensive, worth it for permanent installations
Hardline: Lowest loss, expensive, commercial use

Keep coax runs short: Every foot loses signal. Better antenna with longer coax often worse than worse antenna with shorter coax.

Power Systems

Off-grid communications require off-grid power.

Battery Systems

Lead-acid (deep cycle):

Cheap, heavy, proven
12V common voltage
Solar charge controllers widely available
Maintain with distilled water

Lithium (LiFePO4):

Lighter, longer life, more expensive
Flat discharge curve (full voltage until empty)
No maintenance
Requires battery management system (BMS)

Sizing: Calculate radio power consumption, desired runtime, solar charging capacity.

Example: 50W radio, 8 hours/day = 400Wh/day. 400Wh ÷ 12V = 33Ah. Battery sized for 2 days autonomy = 66Ah minimum. With 50% depth of discharge (lead-acid) = 132Ah battery.

Solar Charging

Panels: 50-200W typical for radio setups Charge controller: PWM (cheap) or MPPT (efficient) Mounting: Fixed angle, adjustable, or tracking

Location: Clear view of sky, oriented for maximum sun

Wind/Human Power

Small wind turbines: Supplement solar, works at night Hand-crank generators: Emergency backup Bicycle generators: Exercise + power

Operational Security

Radio signals can be intercepted, located, and jammed.

Interception

Encryption:

Legal on some ham bands (not on voice in US)
Always legal on non-ham frequencies (FRS/GMRS rules vary by country)
Use available encryption (Meshtastic is encrypted)

Codes/ciphers:

Legal alternative (obscurity, not security)
Pre-arranged codes, book codes, one-time pads
Slow, but secure if done right

Direction Finding (DF)

The threat: Directional antennas can locate your transmitter.

Mitigation:

Use lowest power necessary
Keep transmissions short
Move after transmitting
Use directional antennas pointed away from adversary
Use repeaters (they transmit, you don't reveal location)

Jamming

The threat: Flooding frequencies with noise to block communication.

Mitigation:

Multiple frequencies (frequency agility)
Multiple modes (voice, digital, CW)
Directional antennas (reject off-axis jamming)
Frequency hopping (advanced)

Community and Practice

Nets

Regular on-air gatherings:

Emergency nets: Weekly check-ins, disaster response prep
Swap nets: Buying/selling equipment
Technical nets: Learning, troubleshooting
Social nets: Just chatting

Join nets to practice, learn, build community.

Field Days

ARRL Field Day: Annual event, practice emergency deployment

Set up in field
Generate own power
Make contacts
Test equipment

Local groups often have mini field days for practice.

CERT/RACES/ARES

Community Emergency Response Team (CERT): Local emergency response training Radio Amateur Civil Emergency Service (RACES): Government-activated ham emergency service Amateur Radio Emergency Service (ARES): ARRL emergency coordination

All provide structure, training, relationships for when disasters happen.

The Philosophy of Mesh Communication

Decentralization: No single point of failure, no central authority to compel, censor, or surveil.

Resilience: When infrastructure crumbles, community-built networks persist.

Autonomy: The ability to communicate is a prerequisite for self-organization.

Knowledge as infrastructure: The network exists in the knowledge of how to build it, not in the hardware. Hardware can be lost, seized, destroyed. Knowledge persists.

The commons: The electromagnetic spectrum belongs to everyone. Using it collectively for mutual aid is reclaiming the commons from corporate enclosure.

Practice: Building and maintaining these networks before they're needed ensures they'll work when they are.

Quick Start: Get Communicating This Week

Immediate (no license):

Buy FRS radios ($30/pair)
Test with friends/family
Determine range in your area
Establish channels for different purposes

This month:

Study for Technician license (HamStudy.org)
Find exam session
Buy Baofeng UV-5R or similar
Program local repeaters, emergency frequencies

This year:

Pass Technician exam
Join local ham club
Build antenna, deploy
Participate in nets, field day
Explore packet radio or Meshtastic
Build community communication plan

Resources

Organizations:

ARRL (amateur radio): arrl.org
REACT International (CB emergency): reactintl.org

Learning:

HamStudy.org (license prep)
Ham Radio Crash Course (YouTube)
Meshtastic documentation

Equipment:

BaofengTech (radios)
Gigaparts, Ham Radio Outlet (equipment retailers)

Communities:

Local ham clubs (find via ARRL)
Reddit: r/amateurradio, r/meshtastic, r/preppers

Remember: The network is made of relationships. Equipment enables, but people build resilient communication. Practice, train, build trust, establish protocols before emergencies.

The airwaves are waiting. The mesh is growing. Tune in.