Plug-and-fight is the military equivalent of plug and play as applied to commercial and personal computer systems. Plug-and-fight refers to the capability of certain large military systems such as the Medium Extended Air Defense System (MEADS) to automatically recognize and assemble various system elements, like sensors, weapons, and control nodes, into a single integrated supersystem or system-of-systems. Plug-and-fight systems can be rapidly reconfigured without interrupting operations – adding, removing, and rearranging system elements in response to evolving threats and changing defense strategies. The architecture of such modular systems is often described as netted-distributed.
Plug-and-fight system elements connect to an open wired or wireless communication network through a standardized interface, and have the ability to interact with other system elements on that network to accomplish specific combat objectives. To maximize product applicability, and to ensure the general acceptance of system developers, any plug-and-fight standardized interface should be based on protocols and standards that are widely recognized, well defined, strongly controlled, and non-proprietary. Modern examples include Ethernet, IP, TCP, CORBA, and any specific message structure that can be freely disseminated and used without licensing.
In November 2011, MEADS system elements successfully performed a simulated engagement against real-world air and representative missile threats demonstrating plug-and-fight capabilities. Sensors, shooters, and tactical operations centers (TOC) simply act as nodes on the network, and a military commander can dynamically add or subtract these elements as the situation dictates without shutting the system down.