Telstra Countrywide officially declared its new CDMA tower at Hill Top to be operational on Wednesday, but its own research shows only around 20 per cent of mobile users would benefit immediately.

Area general manager Mark McKenzie said Telstra had followed its policy of "rolling out" CDMA services in non-metropolitan areas, despite

research showing 80 per cent of mobile phone users had a GSM digital phone.

"The CDMA network givers greater coverage from each tower and has far more potential with high speed data transfers through wireless computers, faxes and phones," Mr McKenzie said.

"We are building a network for the future rather than for now."

One Hill Top resident estimated more than 90 per cent of mobile users in the village would have to upgrade to CDMA to take advantage of the new tower.

Mr McKenzie said mobile phones usually only lasted for about two years, and said the cost of purchasing and using a CDMA phone was similar to a GSM phone.

He paid tribute to Hume MP Alby Schultz, whose serious eye injury stopped him attending the opening, for campaigning long and hard for the Hill Top tower.

"This tower will cover Colo Vale, Balmoral Village and down to Thirlmere, completing this north-north-western corner of the Southern Highlands," Mr McKenzie said.

He said a similarly "non-intrusive" Bundanoon tower would soon follow the Hill Top one, as Telstra had found a new site the community was happy with, after a proposed Exeter village site was rejected.

Wingecarribee Shire Council Emergency Management Officer Alan Hollis congratulated Telstra for putting the tower into a bushfire-prone area.

"We know we can send any of our people out here and know that they will have mobile coverage, if necessary," he said.