Pinky - TIEW is correct.
Ballina and Ayers Rock CA/GRS are both operated by a Melbourne-based company, name escapes me it used to be Ambidji, whereas Port Hedland AFIS is staffed by Airservices staff with a Flight Service Officer licence. They can provide a superior service because they are part of ATS and get access to the Perth ATC Centre overlying sectors and there is no traffic information duplication as occurs in the two CA/GRS. They would not be allowed to operate FR24 as a situation awareness tool because they are an ATS.