Ameren had operated several networked trunked systems for its operations , these frequencies have largely been turned over to StarCom21 for general subscriber use .
Ameren , a large utility company that operates in much of Illinois , is now also using StarCom21 .
utility company had operated several networked trunked systems for Ameren 's operations , these frequencies have largely been turned over to StarCom21 for general subscriber use .
Ameren , a large utility company that operates in much of Illinois , is now also using StarCom21 .