1. A fixed, mobile, or transportable structure, including (a) all installed electrical and electronic wiring, cabling, and equipment and (b) all supporting structures, such as utility, ground network, and electrical supporting structures.
2. A network-provided service to users or the network operating administration.
3. A transmission pathway and associated equipment.
5. A real property entity consisting of one or more of the following: a building, a structure, a utility system, pavement, and underlying land.
Source: from Federal Standard 1037C and from MIL-STD-188 and from the Department of Defense Dictionary of Military and Associated Terms