Definition
A computer network that connects devices, systems, or facilities across large geographic distances — typically spanning cities, regions, or countries — using leased telecommunications links, satellite, or internet infrastructure. In aviation, WANs link air traffic facilities, flight service stations, weather systems, and operational centers so they can share data in near real time.
Plain English
A network that links computers and systems spread out over a wide area, so locations far apart can share information as if they were connected in the same building.
Context Anchor
Seen in aviation acronyms and in discussions of electronic weather, flight planning, airport, dispatch, or information systems that depend on connected computers.
Derivation
From 'wide' (broad in extent) and 'area network' (a group of connected computers serving a region). The name simply contrasts with a LAN — a local area network confined to one building or site.
Why Pilots Care
Many of the data services pilots rely on — flight planning systems, weather feeds, NOTAMs, ATC coordination — move across WANs behind the scenes. When a WAN outage occurs, services can degrade or go offline simultaneously across many locations.
Intuition Check
WAN does not mean a wireless network. It means a network spread over a wide area; it may use wired, wireless, satellite, or internet-based connections.
Example Sentence 1
The flight planning provider distributes weather and NOTAM data to subscribers through its WAN.
Example Sentence 2
Air traffic facilities exchange radar tracks over a WAN that spans multiple states.