WWAN refers to wireless high-speed data networks covering a large geographic area. This broad category can include 2.5G, 3G, 4G, WiMax, and other types of technology where each base station (tower) is designed to reach an area measured in miles.
The term WWAN is used primarily to distinguish this group of diverse technologies from WLANs (Wireless Local Area Networks,) which typically cover a much smaller area, such as 100-1000 feet per base station. WLAN includes technology like Wi-Fi.