Communication groups are formed based on mobile station location history. The process includes receiving, at a controller device, a group formation request from a requesting device, the request specifying a location and a time window, identifying one or more mobile stations determined to be within a threshold area relative to the location during the time window, and causing a communication group to be created including the identified one or more mobile stations. A further process includes a requesting device configured to identify a location and time window associated with an event, transmit a group formation request specifying the location and the time window and requesting formation of a communication group comprising mobile stations located within a threshold area relative to the location during the time window, and transmit using a communication group identifier provided to the requesting device.