Telstra said the fault is impacting one sector of a tower, which causes dropouts or calls not to connect.

They have shut down that sector to reduce dropouts while they complete the repairs and because there is overlapping coverage from another tower, so a number of calls will get picked up by that coverage.

It is when the faulty sector is on it blocks them, which is why they have closed it.

A Telstra spokesperson said, “we wish to apologise for the interruption to some 3G services, which is the result of a hardware fault at one of one mobile towers”.

“We are in the process of completing the repairs and hope to restore services as soon as possible.”