A mesh network is a local area network (LAN), wireless local area network (WLAN) or virtual LAN (VLAN) that employs one of two decentralized connection arrangements: full mesh topology or partial mesh topology. In a full mesh topology, each network node (workstation or other device) is connected directly to each of the others. In a partial mesh topology, some nodes are connected to all the others, but others are only connected to those nodes with which they exchange the most data.
The illustration below shows a full mesh network with six nodes. Each node is shown as a sphere and connections are shown as straight lines.
The illustration below shows a partial mesh network with six nodes. Each node is shown as a sphere and connections are shown as straight lines. The connections in either a full or partial network can be wired or wireless.
Mesh networks are expected to play an important part in the Internet of Things (IoT). Unlike nodes in a star topology, which require a router to deliver Internet service, network nodes can "talk" directly to each other without requiring the assistance of an Internet connection. A big advantage of this decentralized topology is that there cannot be a single point of failure (SPoF). If one node can no longer operate, the others can still communicate with each other, directly or through one or more intermediate nodes.
In the past, when mesh networks were always wired, the topology could be expensive (and complicated) to deploy because each node had to be physically connected to the other nodes. Today, however, advances in wireless communication and short-range wireless personal network (WPAN) specifications have removed the physical and financial barriers.