The voice group call service (VGCS) is a mobile communication service for GSM, that allows subscribers to communicate to multiple other subscribers at the same time. For this special mobiles are required that support this function. A first deployment was seen with European Railways. This service is a feature of ASCI (Advanced Speech Call Items) in GSM. The voice group call service (VGCS) is a mobile communication service for GSM, that allows subscribers to communicate to multiple other subscribers at the same time. For this special mobiles are required that support this function. A first deployment was seen with European Railways. This service is a feature of ASCI (Advanced Speech Call Items) in GSM.