An ad hoc node refers to a device in a wireless ad hoc network. Ad hoc networks (or more accurately, mobile, multi-hop, wireless networks) are a class of networks that does not depend on any central administration or infrastructure in its operations. Unlike wired networks, an ad hoc network could be working in an environment in which some or all nodes are mobile.
Nodes (devices) in an ad hoc network typically organize themselves in a temporary structure using short wireless links to immediate neighbours (hops) only. Enabling a node to communicate with other nodes requires the ability to discover and forward messages over multi-hop paths to the destination node. Limited computing resources, wireless channel impediments, and node mobility are some of the challenges that an ad hoc node must cope with to maintain connectivity to the rest of the network.
Ad hoc networks can be classified according to applications as Mobile Ad hoc Networks (MANET), Wireless Sensor Networks, and Vehicular Ad hoc Networks (VANET). Research in ad hoc networks is active in many areas including media access control, routing, and simulation.