Federal Communications Minister Helen Coonan announced further audits of CDMA coverage in Western Australia, Tasmania, Northern Territory and North Queensland will be conducted by the Australia Communications and Media Authority (ACMA).
The audits proceed reviews undertaken in August last year which assessed the coverage of Telstra's aging CDMA network amid plans to succeed it with a 3G850 network, based on 850 MHz WCDMA (Wideband Code Division Multiple Access).
Coonan said the audit will continue efforts to ensure Telstra maintains its CDMA coverage until January 28 next year, and to maintain the service levels of its CDMA and Next G networks.
"The audit process is an important assessment tool to ensure Telstra meets its own public commitment that it will not switch off the CDMA network until coverage on the Next G network is equivalent or better," Coonan said.
"At this stage, further regulatory measures remain an option of last resort, but I will be watching closely and expect that Telstra will meet its public commitment in full before any move is made to switch off their CDMA network.
"These additional audits will mean that every State and the Northern Territory will be sampled over the coming months."
CDMA coverage will be checked through mapping and field testing and will cover a mix of regional, rural and urban areas to give a higher degree of certainty to the results.
The 2006 audits covered about 100 rural, regional and remote sites and assess factors that could impact mobile phone signals such as mixed terrain including flat, mountainous and average terrain, wet rice-growing country and river flats.
"To people outside metropolitan Australia, adequate mobile phone coverage is not only important but a critical need,"Coonan said.
The audits are expected to conclude in the next few months after Telstra has confirmed coverage standards for its 3G850 network