Understanding the Technology What Is LoRa? (For Beginners) LoRa stands for "Long Range." It is a radio modulation technique from Semtech that enables very long range wireless communication at very low power, at the cost of low data rates - the physical layer beneath Meshtastic and MeshCore. How it works LoRa uses chirp spread spectrum - the signal is spread across a wide frequency band using a continuously sweeping chirp tone. This spreading gives LoRa extraordinary resilience to noise. A receiver can decode a packet even when the signal is far below the background noise floor - a capability no conventional modulation scheme matches. Key characteristics Range: 1 - 15 km typical; 30 - 50+ km achievable with elevated antennas Data rate: 0.2 - 22 kbps depending on preset - slower than a 1990s modem, but sufficient for text and GPS Power: Nodes run days to weeks on a small battery; 8 - 50 mA active depending on hardware No subscription: Operates in the unlicensed 902 - 928 MHz ISM band in North America. No SIM, no carrier fees. License-free: Standard operation under FCC Part 15.247 requires no amateur radio license What LoRa is NOT Not WiFi: Far slower, far longer range. No web browsing or streaming. Not cellular: No towers, no coverage maps, no subscription. Works anywhere two nodes are within radio range of each other. Not LoRaWAN: LoRaWAN is a specific hub-and-spoke IoT architecture. Meshtastic and MeshCore are peer-to-peer mesh networks. Same radio hardware, completely different protocols. See the LoRa Mesh vs. LoRaWAN page for the full comparison. Not Bluetooth or Zigbee: Those are short-range (meters). LoRa is long-range (kilometers). Why 915 MHz? The 902 - 928 MHz ISM band is the North American LoRa mesh standard because it is unlicensed under FCC Part 15, has better building and vegetation penetration than 2.4 GHz, has a low ambient noise floor, and yields practical antenna sizes (~8 cm quarter-wave). The fundamental tradeoff LoRa's extreme range comes at the cost of speed. A 50-byte text packet takes several hundred milliseconds to transmit. This is fine for messaging and GPS tracking - and impossible for voice, video, or large files. Design your use case around this constraint and LoRa delivers remarkable results. LoRa Mesh vs. LoRaWAN Both use the same LoRa radio chips but operate completely differently. This is the most common source of newcomer confusion. LoRaWAN A hub-and-spoke network designed for IoT sensors reporting to the cloud. End devices transmit to fixed gateways; gateways forward over the internet to a server. No direct device-to-device communication. No gateway in range = no connectivity. Examples: The Things Network, Helium. LoRa Mesh (Meshtastic, MeshCore) A peer-to-peer network where nodes communicate directly and relay each other's messages. Works completely offline - no internet required. Messages hop: A → B (relay) → C → D. Adding nodes makes the network stronger. Examples: Meshtastic, MeshCore. Comparison table Feature LoRaWAN LoRa Mesh Architecture Hub-and-spoke Peer-to-peer Internet required Yes No Direct messaging No Yes Multi-hop relay No Yes Works without infrastructure No Yes Typical use case Sensor data to cloud Off-grid comms, group coordination They cannot communicate with each other. Different packet formats, addressing, and network stacks - they share hardware but speak different protocols. Important: LoRaWAN gateways won't build a mesh LoRaWAN gateways ($100 - $300) are one-way forwarders to the internet, not mesh relays. To build a LoRa mesh network you need Meshtastic- or MeshCore-compatible devices, not LoRaWAN gateways. How Mesh Routing Works When two nodes are too far apart to communicate directly, intermediate nodes relay the message. Meshtastic and MeshCore solve this differently. Flooding (Meshtastic) When a node receives a packet, it rebroadcasts to all neighbors. Each node rebroadcasts once (duplicate detection prevents loops). The message floods outward until it reaches its destination or exhausts its hop count (typically 3 - 5 hops). Simple and robust: No routing tables. New nodes work immediately. Self-healing if relay fails. Limitation: One message can trigger 30 - 50 transmissions across a dense network. Why faster presets (Medium Slow) are preferred in networks with many nodes. Path-based routing (MeshCore) MeshCore discovers explicit routes before sending data: Node A broadcasts a path discovery packet ; each relay appends its identity Destination node D sends back a path acknowledgment along the reverse path Node A caches the route A → B → C → D and uses it for all subsequent messages to D More efficient at scale: Messages travel only the established path - much less airtime than flooding in large networks Limitation: Route discovery adds latency to first contact. Topology changes require re-discovery. Which is better? Both work well in practice. Flooding is simpler and more resilient for small-to-medium networks (under ~100 nodes). Path-based routing scales better for large infrastructure deployments. In practice, your choice is determined by which protocol your local community uses. The mesh advantage Every additional node is a potential relay. A hilltop repeater that can hear both a valley and a distant mountaintop effectively bridges those two coverage zones for all messages. A few well-placed infrastructure nodes have outsized impact on total network reach.