Mobile phones will carry 50 per cent of all voice traffic by 2008

By next year, half of all voice traffic in Western Europe is likely to be generated by mobile phones, according to IT, media and telecoms researcher Analysys.

But while fixed line operators are suffering the financial fall out of users' increasing fondness for mobility, not all mobile players are automatically benefiting from their loss.

Many mobile players have historically squeezed costs to reduce customer churn and increase loyalty. They've continued this trend to attract customers away from their landlines and towards fixed/mobile substitution (FMS), but some have made the mistake of assuming that usage will get to such a level that it will offset their hefty price cuts, claims Analysys.

"FMS is generally seen as a threat for fixed operators and an opportunity for mobile operators. However, while fixed operators' voice call revenue is falling substantially due to FMS, not all mobile operators are seeing revenue gains as a result," says Dr Alastair Brydon, co-author of Analysys' research report.

"To avoid declines in voice ARPU, mobile operators need to achieve significant increases in usage to compensate for price cuts, and some operators are doing much better than others."

Citing Finland and Portugal as prime examples of countries that have increased FMS adoption rates to their financial detriment, Analysys warned operators in other geographies to exercise caution.

In Finland, for example, the level of voice traffic originating on mobile phones rose from 55 per cent in 2004 to 70 per cent last year, but the average spend per mobile minute fell by 34 per cent. Mobile usage per capita increased by less than a quarter (23 per cent) during the same period, resulting in a net fall in average revenue per user (ARPU).