A Wireless LAN (WLAN) is a Wireless Local Area Network that uses radio waves as its carrier. The backbone network is usually wired and provides one or more wireless access points connecting the wireless devices to the wired network. So, communication distance is often constrained by the availability and location of access points. A Wireless Mesh Network on the other hand relies on all the nodes in the network to facilitate communication, thus extending the transmission distance upto the farthest node, where each node has atleast one reachable neighboring node that is closer to the base station. Since each node acts like a repeater in mesh networks, the more the number of nodes, the more the bandwith and the stronger the signal that reaches the access point.

If you are looking for a definition of a Mesh Network –

A mesh network is a network that employs one of two connection arrangements, full mesh topology or partial mesh topology. In the full mesh topology, each node is connected directly to each of the others. In the partial mesh topology, nodes are connected to only some, not all, of the other nodes.

  • Wireless Mesh Networking (O’Reilly Network)
  • From the Editor: Mesh Networking Matters (TechnologyReview.com)

Last week, PacketHop released its TrueMesh mobile mesh networking software and a suite of multimedia applications that provide instant wireless group communication. According to InformationWeek –

The concept could be especially useful for law-enforcements agencies that need to set up a network around an incident scene. They can use the suite of multimedia applications to instant message each other, send photos of suspects, whiteboard on the photos, and stream video if they have cameras connected to their mobile devices. Additionally, they can locate and track different law-enforcement units that are part of the network on electronic maps.

An Instant and Mobile Wireless Mesh Network (Roland Piquepaille’s Technology Trends)