Aircraft Communications Addressing and Reporting System (ACARS) is a digital datalink system for transmission of short,and relatively simple messages between aircraft and ground stations using the airband VHF radio link. The message protocol was designed by Aeronautical Radio Incorporated (ARINC) to replace their VHF voice service and deployed in 1978 using telex type format. SITA, a multinational information technology company, later augmented their worldwide data network by adding ground radio stations to provide ACARS service.