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In a mesh network topology there is no central connection point. Instead, each node is connected to at least one other node and usually to more than one. Each node is capable of sending messages to and receiving messages from other nodes. The nodes act as relays, passing on a message towards its final destination.

There are two types of mesh network topology:

• full mesh network topology
• partial mesh network topology

Mesh network topologies are becoming increasingly popular due to their efficiency.

With a full mesh network topology, each node is directly connected to every other node. This enables a message to be sent along many individual routes.

With a partial mesh network topology, not all nodes are connected directly to each other. A partial mesh therefore has fewer routes for a message to travel along than a full mesh, but it is simpler to implement.

Wired mesh network topologies tend to be uncommon, mainly because connecting all nodes to all other nodes is expensive and impractical. However, wireless mesh network topologies are increasingly being used since it is far simpler and cheaper to connect using radio signals.

Advantages and disadvantages of using a mesh network topology

Having nodes arranged in a mesh network topology brings some benefits:

• messages can be received more quickly if the route to the intended recipient is short
• messages should always get through as they have many possible routes on which to travel
• multiple connections mean - in theory - that no node should be isolated
• multiple connections mean each node can transmit to and receive from more than one node at the same time
• new nodes can be added without interruption or interfering with other nodes

However, mesh network topologies also have their disadvantages:

• full mesh network topologies can be impractical to set up because of the high number of connections needed
• having many connections means that a lot of maintenance is required
• a large part of the network may be redundant if there are better routes to connect nodes, making some connections unnecessary

Mesh network topologies in use

Mesh network topologies are used where the reliability of network communication is very important:

• military organisations often use mesh network topologies to avoid breakdowns in communication
• cities are increasingly using wireless mesh network topologies to help monitor traffic flow and sewage treatment, and to help control street lighting
• emergency services, such as police and fire services, also use wireless mesh network topologies to ensure that communication is reliable
• some utility companies who provide gas and electric use mesh network topologies to allow smart meters to send readings automatically