For emergency calls, when a caller dials 9-1-1, the phone number from which they call determines which 9-1-1 center receives the call for assistance. Cell phone calls are processed based on the closest cellular tower. Once the dispatcher analyzes the EMS situation, they will notify the closest appropriate EMS agency for response. Many 9-1-1 centers communicate with the EMS agencies via computer-aided dispatch software. Scheduled and non-emergency calls do not get dispatched through 9-1-1. Rather the referring hospital, skilled nursing home, or other caretakers or facilities will coordinate the transport directly with the EMS agency. Dispatch software is often used as a tool to coordinate schedules between facilities and EMS agencies.