Mesh Networking

Mesh networking is a decentralized communication system in which each device (or “node”) acts as both receiver & repeater, automatically relaying data for other nodes. Instead of relying on a central router, access point, or cellular tower, messages “hop” from node to node until they reach their destination.

The lack of central authority in mesh networks makes them extremely popular for those looking to bypass traditional ISP monopolies, cell towers, and draconian censorship laws.

Fig. A: A comparison of several common network topologies.

Mesh networks are typically crowdsourced operations which rely on a predefined set of standards to define the rules of the network. Since there is no central authority to the network beyond the rules of the protocol everyone settled upon at the beginning, anyone can spin up new nodes on the network. This creates a resilient, self-healing network that can cover large areas, operate without internet or cellular infrastructure, and continue working even if some nodes fail or go offline.

Most other types of networks have bottlenecks which packets pass through, such as central gateways or routers. When those bottlenecks fail (or are targeted for sabotage) vast swaths of the network go down with them. Mesh networking avoids this problem through the use of multiple redundant nodes. See Figure A for a visual comparison.

Mesh networks come in many forms & protocols, and these protocols are not interchangeable. However, they all share the core advantage of operating independently of traditional telecom infrastructure, making them valuable for remote areas, emergency situations, or censorship-resistant communication.

If you are looking to communicate with people outside your immediate periphery, you will need to dive into one of the popular long-range mesh networks. The biggest and most robust networks will be of this type. Here are some major ones:

LoRa (for Long Range) is a radio modulation technique for long-range, low-power communication over amateur radio and the sub-gigahertz ISM bands (915MHz in the US, and 433MHz & 868MHz in Europe). It achieves ranges of 1-9mi (2–15km) while consuming minimal energy, making it ideal for simple text-messaging & IoT sensors that only need to transmit small packets occasionally. LoRA has been adapted for use with several types of mesh-based and non-mesh networks, such as Meshtastic and LoRaWAN (see below).

LoRaWAN is one of the most popular LoRa implementations. Before we continue, it should be noted LoRaWAN is not a true mesh network. Rather it is extended-star (or “star-of-stars”) topology, ie: devices talk only to gateways. It trades very low data rates (0.3–50kbps) for exceptional range and robustness against interference. LoRaWAN devices can last 5–10 years on a single battery, and operate over distances of 2–15km, while sending data only a few times per hour or day.

Unlike true mesh systems, devices in standard LoRaWAN do not relay messages for each other — all traffic goes through gateways connected to the internet or private backhaul. We mention it here because other mesh systems oftentimes work on the same hardware, which is a major source of confusion for mesh newbs. However, LoRa can also be used in pure peer-to-peer mesh configurations such as Meshtastic (see below).

Unlike LoRaWAN, Meshtastic is a true long-range mesh system built on LoRa hardware where every device is its own independent node. Meshtastic nodes automatically rebroadcast messages from nearby Meshtastic nodes, creating self-reliant off-grid text messaging & location-sharing networks that can transmit data up to a whopping 37kbps! It's not practical at all for transmitting media (or anything with a large file size) but it excels at plaintext, which is quite versatile if you know how to work it.

The Meshtastic firmware can be installed on any compatible ESP32-based device. There are many prebuilt Meshtastic devices on Amazon, some of which have Bluetooth and smartphone connectivity. It is especially popular with hikers, preppers, and disaster-response groups. Range per hop is typically 2-10 miles or 5–15 kilometers in good conditions, but records of 100-200 miles have been achieved.

If you are new to mesh networking, Mestastic is one of the easier entry points. If you are looking to DIY your own Arduino-esque off-grid texting device with a 3D printed case, this is the network most hobbyists are doing that on. For more information on Meshtastic devices and how to use them, read our Meshtastic guide.

Helium is a LoRaWAN-based network originally launched in 2019, which uses community-deployed “Hotspots” that people buy and host at home. These hotspots provide long-range LoRaWAN coverage, relay data to the internet, and form a global blockchain-based network where participants originally earned $HNT cryptocurrency for proof-of-coverage & data transfer. Because of the financial incentive, Helium became notorious for its users setting up hotspots in National Parks & Forests.

In 2023–2024 the original project split: The IoT/LoRaWAN portion migrated to the Solana blockchain as Helium IoT, while a separate Helium Mobile network now focuses on 5G/cellular offloading using the same hotspot model & tokenomics. Today it remains one of the largest crowdsourced LoRaWAN networks, with hundreds of thousands of hotspots worldwide.

Project OWL (Organization, Whereabouts & Logistics) is an open-source initiative that centers on “DuckLink” devices: small, solar- or battery-powered LoRa nodes that form ad-hoc clusters called ClusterDuck networks. DuckLink nodes relay small data packets like location, messages, and sensor readings over distances up to 1 km per hop. Specialized nodes can be set up to communicate with smartphones and even function as internet gateways.

Like Meshtastic, it is a true open-source mesh system that can be run on any compatible device. Unlike Meshtastic, there is far more fine-grained control over how ClusterDuck networks behave. If you find yourself feeling 'limited' by Meshtastic, this option might be worth considering.

An opportunistic mesh network is a decentralized, self-forming wireless network in which nodes automatically discover each other, connect, and relay data only when they happen to be within radio range of each other. It does not require any pre-existing infrastructure, fixed topology, or central coordination. It’s a mesh that works by taking advantage of whatever temporary contacts happen opportunistically, rather than assuming constant connectivity or fixed relays.

Unlike traditional or planned meshes (e.g., city-wide Wi-Fi mesh or Meshtastic’s long-range LoRa mesh) opportunistic meshes rely on mobility and chance encounters: Nodes carry messages in a “store-carry-forward” fashion, holding data until they physically move close enough to another node (or another node moves close to them) to exchange or forward it.

Briar is an open-source, peer-to-peer messaging app for Android (with desktop support) specifically designed for censorship-resistant and offline communication. It can synchronize encrypted messages, contacts, and group chats directly via Bluetooth and Wi-Fi, and optionally through Tor. When multiple devices are in range, Briar automatically forms a temporary mesh, relaying messages hop-by-hop through intermediates even if the sender and recipient are not directly connected.

Syncthing is an open-source, peer-to-peer file synchronization tool that continuously keeps folders identical across multiple devices (phones, laptops, servers) without relying on any central cloud server. It normally uses the internet for discovery and relaying, but when devices are on the same local network (ie: Wi-Fi or Bluetooth) or when internet is unavailable, it can automatically fall back to direct local connections and even route traffic through other nearby Syncthing nodes, effectively creating an ad-hoc mesh for file transfers.

While the above applications & protocols make some types of mesh networking easier, you do not need any of them. Any LAN or local area network can be set up as a type of mesh network. Pretty much every major operating system has LAN support, meaning all you have to do is plug your computer into the LAN and it will usually autodetect. There is nothing stopping you from running miles of LAN cables and wifi repeaters with your friends to create a city-wide LAN. In fact, residents of cities like Havana, New York, Barcelona, Berlin, Rome, Toronto and more, have done exactly that to varying degrees of success.

If your mesh requires persistent connections, fast speeds and the ability to transfer large files, this is the type of mesh you will want to build.

For the ease of teaching this subject, we focus our R&D on the mesh deployments covered above. However, those deployments are just a sampling of the many types of mesh networks out there - particularly actively-maintained ones enjoyed by our students. If you need more examples of this concept, check out some of these projects:

The goTenna is a commercial mesh networking device using ISM bands, controlled by your smartphone. Like Meshtastic, it is a true peer-to-peer mesh system. Unlike Meshtastic, it is proprietary system marketed mainly to tactical response teams and professional outdoorsmen. Not worth investing in this one unless you are working with other goTenna users.

The Serval Project was one of the earliest smartphone-based mesh projects (2010s) that turned Android phones into walkie-talkies & text relays over Wi-Fi and/or Bluetooth. It is largely inactive now, but it was very influential on the development of modern mesh-based ecosystems.