By Daniel Eran Dilger

Published: 03:35 PM EST

Australian mobile provider Telstra has awarded iPhone 4, when used with a case, a special "Blue Tick" approval for use in rural areas of poorer service coverage, due to the phone's antenna performance.

In a blog posting titled "tips for great iPhone reception, Telstra says iPhone 4, without the use of any accessories, has been approved for use in metro and major regional coverage areas.

The carrier notes that "to help maximise coverage performance in metro and major regional areas, Telstra recommends that customers team their iPhone 4 with an approved rubberised bumper or case."

The tip adds, "we’ve found that an approved bumper or case can also improve the consistency of data speeds when customers are using a fast network like the Telstra Next G™ network. So if frequent mobile internet is important to you, we suggest you grab a bumper or case."

Blue Tick worthy for rural customers, when a case is used

"The great news for our regional and rural customers," Telstra says, "is that an approved rubberised bumper or case can help to maximise the coverage performance of the iPhone 4. In fact, the handheld coverage performance is improved so that it is equivalent to one of our Telstra ‘Blue Tick’ devices."

The posting explains, "we award our Blue Tick to mobiles that have the best coverage performance and recommend them to customers working or living in regional and rural coverage areas."

Telstra adds that it "uses a two-phase methodology to test the coverage performance of each mobile phone model it offers to customers. The first test is conducted at Telstra’s anechoic chamber in Sydney and examines a mobile’s handheld receiver sensitivity. The second test is conducted out in the field. Testing looks at elements like voice quality and how successfully a handset makes and receives calls at the edge of coverage."



iPhone 4 launches in Australia tomorrow, along with Austria, Belgium, Canada, Denmark, Finland, Hong Kong, Ireland, Italy, Luxembourg, Netherlands, Norway, New Zealand, Singapore, Spain, Sweden and Switzerland.