Wireless mesh network technology was first researched by Defense Advanced Research Projects Agency (DARPA) in the mid-1990s for battlefield communications purposes, but study of meshes soon expanded into such research and development (R&D) companies as SRI International. Currently such startups as MeshNeworks, Tropos, FireTide, BelAir, and PacketHop, among others highlighted, say their offerings will transform the wireless landscape. Wireless meshes use a topology of redundant connections between nodes to build an auto-configuring, automatic-healing network. Very few nodes need be wired into the network, so mesh networks reduce the need for costly backhaul and provide other benefits, including dynamic optimized routing and automatic load balancing. A spokesman for Tropos Networks says his systems clients do not participate in the mesh, and that meshing is done by infrastructure devices. MeshNetworks and PacketHop permit clients to actively take part in the mesh, but both depend on infrastructure nodes for the core of the mesh networks. Fixed mesh can be a cable replacement, and a spokesman for Strix Systems says mesh technology permits deployments of wireless LANs in areas where Ethernet is problematic, costly, or not available at all. Among topics covered are the different types of mesh topologies; meshes as opposed to wireless LANs (WLANs); and use of mesh technology from PacketHop by the California Governor's Office of Emergency Services in implementation of a mobile network of boats, cards, and officers on foot.