Smoke Signals transmit data at about 2 bits per second. Use it as a last resort.
Text and Talk without the Grid
Instead, use walkie talkies and long range (LoRa) radio transmitters over a Meshtastic network to communicate by voice and to text, respectively, when internet and cellular service is unavailable.
Walkie Talkies
These are very useful during a grid-down situation, or on the occasion when cell service isn’t available. Walkie Talkies don’t rely on cell towers and allow voice communication over distances up to about a mile (1600m).
In urban settings where there are plenty of obstructions, communication distance might degrade to about 500m.
Standard Family Radio Service (FRS) walkie talkies are simple to use, can be bought off the shelf and don’t require a license.
More powerful General Mobile Radio Service (GMRS) walkie talkies have much longer range (1 mile to 5 miles) and can access radio frequencies that FRS radios cannot. They require an FCC license to operate.
Their limitation is their range and power consumption, although many newer models, like the Rocky Talkie below, can operate for several days before requiring a recharge.
Meshtastic + LoRa Radio Transmitters
Meshtastic is a project that combines open-source software with off-the-shelf hardware to create a low-cost, long-range, and decentralized mesh network. This decentralized network is primarily designed for sending text messages and GPS locations between users, making it ideal for outdoor activities, emergencies, or situations where traditional communication networks are unavailable or unreliable. The network operates over LoRa (Long Range) radio technology, which allows for communication over distances of tens of kilometers, depending on the terrain and hardware used.
The throughput of Meshtastic LoRa networks is low compared to traditional Wi-Fi or cellular networks as the system prioritizes long-range communication and low-power consumption over high data rates. In other words, sending short text messages is fine, however voice communication is impossible.
The Meshtastic project aims to provide a flexible and accessible communication solution that can be used with various devices, including dedicated Meshtastic devices built from compatible LoRa modules and GPS units, as well as smartphones via Bluetooth connection to a Meshtastic device. The software allows for the encryption of messages, ensuring privacy and security for its users.
LoRa is Device Agnostic
Meshtastic can work with many different types of LoRa radios. The project is designed to be hardware-agnostic to a significant extent, supporting a range of LoRa modules and development boards. This flexibility allows users to build Meshtastic devices from various off-the-shelf components based on their specific needs, preferences, and budget.
The software is primarily developed and tested with a few popular LoRa modules and boards, such as those based on the ESP32 microcontroller combined with a SX127x or SX126x LoRa transceiver. The ESP32 chip is older and consumes more power than the newer nRF52 chip, but is equipped with both WiFi and Bluetooth.
Examples of commonly used ESP32 hardware include:
- Heltec WiFi LoRa 32
- LilyGo T-Beam and LilyGo TTGo LoRa
While Meshtastic LoRa devices are gaining most popularity with the hobbyist crowd, most devices are cheap to buy ($30-$40) and easy to get started with despite their intimidating minimalist appearance.
Meshtastic provide comprehensive documentation, downloads and a guide to getting started with their LoRa network, in addition to recommendations on hardware to use.
Walkie Talkie + Meshtastic LoRa Radio Solution
Having on hand both walkie talkies for shorter distance voice communication and Meshtastic LoRa devices connected to your cellphone for texting over longer distances make a comprehensive solution in the event that cellular and internet communication isn’t possible.