Despite the rise in the number of 3G mobile users, 2G continues to underpin Optus' revenues, the company said.

Despite the rise in the number of 3G mobile users, 2G continues to underpin Optus' revenue, the company said.

In an ASX presentation, group director products and delivery Chris Lane said mobile data usage was underpinning mobile phone revenues.

For the Q4 FY06 quarter, mobile data was expected to grow 16 percent through increased use of its SMS service. The average revenue per user (ARPU) for SMS was expected to grow 17 percent in the same period.

Year-on-year this represented 34 percent growth from an average of 34 messages per user in Q4 FY05 to 46 in Q4 FY06.

Non-SMS services also continued to grow but at a more modest rate, increasing from 1.1 percent of data use to 2.4 percent over the same period.

Premium SMS services also grew 150 percent, content downloads by 85 percent, and data browsing by 120 percent between Q4 FY05 to Q4 FY06.

While three 3G services were expected to account for an increasing proportion of mobile data revenues, the expectation for 3G's role was now an “evolution not revolution,” with a gradual roll-out of coverage planned, the company said.

As at March, 50 percent of the population was covered through some 1200 3G base stations. By March 2007, this was expected to grow to only 60 percent of the via a planned 2000 base stations, Optus said.