Wireless Ad-hoc Station
Observer has sensed ad-hoc network activity. Since most corporate WLANs are infrastructure networks (in other words, they depend up APs to create a wireless portal to the wired LAN), ad-hoc activity may be considered a security breach or possible misuse of company laptops.
Possible reasons for the event:
A user has deliberately or inadvertently configured the local LAN setup options to ad-hoc mode.
Observer is sensing ad-hoc traffic from an outside network.