Mesh network

An example mesh network, where node "A" is able to reach node "Q" without a direct link. Multiple routes could be used.

A Mesh Network is a networking topology which utilizes non-hierarchical connections to between a series of nodes, to deliver messages through indirect paths. This network topology facilitates communication between two points which do not have a direct connection which one another. Each device (node) in a mesh network, will send out its own messages, while also relaying messages sent by others, not intended for itself. In this manner, a message sent by one device may "hop" through several other devices in undefined ways, before reaching its destination. While this does cause many unneeded re-sends (amounting to useless noise), it enables communication through paths which would otherwise be impossible.

Uses

Mesh networking has become popular for applications such as building out a Wireless Local Area Network (WLAN), reducing the need for cabling and other infrastructure. Traditionally, each wireless access point is cabled directly to a switch, through which all traffic destined for the wider network is routed. Instead, a mesh network can be created, whereby one access point receives a message, relays that message to its neighboring access points wirelessly, which themselves rebroadcast it again, until the message reaches an access point physically connected to an upstream switch. In this way, only one access point needs to be physically wired to the core switch, while others need only to be supplied with electricity. This does result in higher overheard, and thus lower throughput, but is simpler to deploy.

Similar logical designs are used for a variety of other things as well, such as enabling communication between two distant parties without the use of telecommunications systems. For example, the Briar messenger attempts to use a mesh network over Bluetooth and WiFi networks, to pass messages across a localized mesh. Similarly, Meshtastic forms a mesh network using an ISM band, to deliver messages through a longer-range mesh network.