Cross-settlement wireless communication

LoRa, shortwave, mesh

In the aftermath of a societal collapse, re-establishing reliable communication between dispersed settlements is critical for survival, coordination, and rebuilding efforts. Cross-settlement wireless communication enables communities to share information, coordinate resources, and maintain social cohesion over distances that exceed the range of simple line-of-sight methods. This section provides a comprehensive guide to three primary wireless communication technologies suitable for early digital civilization recovery: LoRa (Long Range), shortwave radio, and mesh networks. Each technology has unique advantages, limitations, and implementation requirements, which will be explored in detail to help survivors select and deploy the most effective communication systems for their circumstances.

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Overview of Cross-Settlement Wireless Communication

Cross-settlement communication refers to wireless methods that connect multiple communities or nodes separated by kilometers or tens of kilometers, often over challenging terrain. Unlike local communication confined to a single building or camp, these systems must overcome obstacles such as hills, forests, and atmospheric conditions.

Key goals for cross-settlement wireless communication include:

• Long range: Cover distances from several kilometers up to hundreds of kilometers.
• Low power consumption: Operate on limited energy sources such as batteries or solar panels.
• Reliability: Maintain stable connections despite environmental interference.
• Scalability: Support multiple nodes or settlements in a network.
• Simplicity and maintainability: Use technology that can be repaired or built with limited industrial infrastructure.

The three technologies discussed here—LoRa, shortwave radio, and mesh networks—address these goals in different ways and are complementary rather than mutually exclusive.

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LoRa (Long Range) Communication

What is LoRa?

LoRa is a wireless modulation technique designed for long-range, low-power communication. It operates in sub-gigahertz frequency bands (typically 433 MHz, 868 MHz in Europe, and 915 MHz in North America), which allows signals to travel several kilometers in rural or semi-urban environments.

LoRa is often used in Internet of Things (IoT) applications today, but its properties make it highly suitable for post-collapse communication networks where power and infrastructure are limited.

Technical Characteristics

• Frequency bands: Unlicensed ISM bands (e.g., 433 MHz, 868 MHz, 915 MHz).
• Range: Typically 2–15 km in open areas; up to 30 km with ideal line-of-sight.
• Data rate: Low, from 0.3 kbps to 50 kbps, sufficient for text messages, sensor data, or short commands.
• Power consumption: Very low; devices can run for months or years on small batteries.
• Modulation: Chirp Spread Spectrum (CSS), which provides robustness against interference and multipath fading.

Advantages of LoRa for Cross-Settlement Communication

• Long range with low power: Ideal for battery-powered or solar-powered nodes.
• Robustness: Resistant to noise and interference, suitable for rural terrain.
• Simple hardware: Can be built or repaired with basic electronic skills.
• Network flexibility: Supports star or mesh topologies with gateways.

Limitations

• Low bandwidth: Not suitable for voice or large data transfers.
• Line-of-sight dependency: Range decreases with obstacles like hills or dense forests.
• Limited commercial availability post-collapse: Requires salvaged or homemade transceivers.

Implementing LoRa Networks

1. Hardware components:

   • LoRa transceiver modules (e.g., Semtech SX127x series).
   • Microcontroller (e.g., Arduino, ESP32) for control and data handling.
   • Antennas tuned to operating frequency.
   • Power source: rechargeable batteries with solar panels preferred.

2. Network design:

   • Use a star topology with a central gateway connected to multiple nodes.
   • Gateways can be linked to local servers or message relays.
   • Deploy repeaters or additional nodes to extend coverage.

3. Data protocols:

   • Use lightweight protocols such as LoRaWAN or custom simple messaging.
   • Implement error correction and acknowledgments for reliability.

4. Applications:

   • Sending text messages or alerts between settlements.
   • Transmitting sensor data (weather, water levels, security).
   • Coordinating resource sharing or emergency responses.

Example Use Case

A cluster of settlements within a 10 km radius sets up LoRa nodes on rooftops or hills. Each node relays messages to a central gateway connected to a local server. This system enables daily communication, weather alerts, and coordination of supply runs without relying on high-power radios or internet infrastructure.

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Shortwave Radio Communication

What is Shortwave Radio?

Shortwave radio uses high-frequency (HF) bands from approximately 3 MHz to 30 MHz to transmit signals over very long distances by reflecting radio waves off the ionosphere. This phenomenon, called skywave propagation, allows communication beyond the horizon, sometimes thousands of kilometers away.

Shortwave radio has been a backbone of global communication for decades and remains a powerful tool for cross-settlement communication in low-infrastructure environments.

Technical Characteristics

• Frequency range: 3 MHz to 30 MHz.
• Range: From tens to thousands of kilometers depending on frequency, time of day, and atmospheric conditions.
• Data rate: Variable; voice and Morse code (CW) are common; digital modes possible with specialized equipment.
• Power consumption: Moderate to high depending on transmitter power.
• Modulation: AM, SSB (Single Side Band), CW (Morse code), and digital modes like PSK31 or FT8.

Advantages of Shortwave Radio

• Very long range: Can connect distant settlements or regions.
• Mature technology: Many radios and parts exist in salvageable form.
• Multiple communication modes: Voice, Morse code, and digital data.
• No infrastructure needed: Can operate independently of local networks.

Limitations

• Power requirements: Transmitters often require tens to hundreds of watts.
• Complexity: Requires more technical skill to operate and maintain.
• Atmospheric variability: Signal quality depends on time of day, solar activity, and weather.
• Large antennas: Effective operation requires sizable antennas, often wire dipoles or long wires.

Implementing Shortwave Radio Systems

1. Hardware components:

   • Transceiver capable of HF bands (e.g., vintage military surplus, amateur radios).
   • Power amplifier for increased range if available.
   • Antennas: long wire, dipole, or vertical antennas tuned to operating frequencies.
   • Power source: batteries, generators, or solar with energy storage.

2. Operating procedures:

   • Select frequencies based on time of day and propagation charts.
   • Use voice for simple communication; Morse code for low-power, long-distance.
   • Digital modes can be used with computers and sound cards for efficient data transfer.

3. Network design:

   • Establish scheduled communication windows to conserve power.
   • Use call signs and protocols to identify settlements.
   • Maintain logs of transmissions for coordination.

4. Applications:

   • Emergency broadcasts and alerts.
   • Coordination of aid and resources over large distances.
   • Sharing news and information between isolated communities.

Example Use Case

A regional network of settlements uses shortwave radios to hold daily scheduled check-ins. Operators transmit weather reports, security updates, and requests for assistance. Morse code is used during low-power periods, while voice communication is preferred when power is abundant.

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Mesh Networks

What is a Mesh Network?

A mesh network is a decentralized wireless network where each node (device) connects directly, dynamically, and non-hierarchically to as many other nodes as possible. This creates a resilient network where data can hop from node to node until it reaches its destination.

Mesh networks can be implemented using various radio technologies, including Wi-Fi, LoRa, or other RF protocols, depending on range and bandwidth needs.

Technical Characteristics

• Topology: Decentralized, self-healing, and scalable.
• Range: Depends on radio technology; can be from hundreds of meters (Wi-Fi) to several kilometers (LoRa).
• Data rate: Varies widely; Wi-Fi mesh supports high bandwidth, LoRa mesh supports low bandwidth.
• Power consumption: Varies; low for LoRa mesh, higher for Wi-Fi mesh.
• Routing: Dynamic routing protocols determine optimal paths.

Advantages of Mesh Networks

• Resilience: Network can route around failed nodes or obstacles.
• Scalability: Easily add new nodes to extend coverage.
• No central infrastructure: Avoids single points of failure.
• Flexible deployment: Can cover complex terrain and urban environments.

Limitations

• Complexity: Requires knowledge of network protocols and configuration.
• Power usage: Nodes must be powered continuously or regularly.
• Range limitations: Wi-Fi mesh nodes typically require line-of-sight or short distances.
• Hardware availability: Requires compatible radios and computing devices.

Implementing Mesh Networks

1. Hardware components:

   • Wireless routers or single-board computers with Wi-Fi or LoRa radios.
   • Power sources: mains, batteries, or solar panels.
   • Antennas optimized for range and environment.

2. Software and protocols:

   • Use open-source mesh routing protocols such as BATMAN, OLSR, or Zigbee mesh.
   • Configure nodes for automatic discovery and routing.
   • Implement security measures like encryption and authentication.

3. Network design:

   • Deploy nodes at strategic locations to maximize coverage.
   • Balance node density to optimize performance and power consumption.
   • Monitor network health and adjust topology as needed.

4. Applications:

   • Local internet sharing or intranet services.
   • Messaging and file sharing between settlements.
   • Sensor networks for environmental monitoring.

Example Use Case

A group of settlements within a 5 km radius sets up a Wi-Fi mesh network using solar-powered routers on rooftops. The mesh supports local file sharing, voice-over-IP calls, and emergency messaging without relying on external infrastructure.

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Comparative Summary and Integration Strategies

Feature	LoRa	Shortwave Radio	Mesh Networks
Typical Range	2–15 km (up to 30 km line-of-sight)	Tens to thousands of km (skywave)	Hundreds of meters to several km
Data Rate	Low (up to 50 kbps)	Variable (voice, Morse, digital)	Medium to high (Wi-Fi mesh) or low (LoRa mesh)
Power Consumption	Very low	Moderate to high	Medium to high
Infrastructure Needed	Minimal	Antennas, power amplifiers	Multiple nodes, routers
Complexity	Low to moderate	Moderate to high	High
Best Use Case	Local to regional text/data	Long-distance voice/data	Local area networks

Combining Technologies

For robust cross-settlement communication, survivors should consider integrating these technologies:

• Use LoRa for low-power, daily messaging and sensor data within a 10–15 km radius.
• Deploy shortwave radios for long-distance communication beyond LoRa’s range, especially for emergency broadcasts.
• Establish mesh networks within and between settlements for local high-bandwidth communication and resource sharing.

This layered approach ensures redundancy, flexibility, and coverage across various distances and conditions.

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Practical Considerations for Post-Collapse Deployment

Salvage and Repair

• Scavenge electronic components from old radios, IoT devices, and computers.
• Learn basic electronics repair: soldering, antenna tuning, and circuit testing.
• Fabricate simple antennas from wire, metal rods, or tubing.

Power Solutions

• Prioritize renewable energy: solar panels with battery storage.
• Use energy-efficient devices and duty cycling to conserve power.
• Maintain backup power sources like hand-crank generators or fuel-based generators.

Training and Knowledge Sharing

• Train community members in radio operation, maintenance, and troubleshooting.
• Document frequencies, protocols, and schedules for consistent communication.
• Establish communication etiquette and emergency codes.

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Conclusion

Cross-settlement wireless communication is a cornerstone of rebuilding a connected and resilient society after collapse. LoRa, shortwave radio, and mesh networks each offer unique capabilities that, when combined, provide a comprehensive communication infrastructure adaptable to varied environments and resource availability.

By understanding the technical principles, advantages, and limitations of each technology, survivors can design and implement effective wireless networks that enable information flow, coordination, and mutual support across dispersed communities.

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