Mobile networks are updating their billing infrastructures or introducing new ones to meet the demands of general packet radio service (GPRS).

Operators have been forced to rethink their pricing strategies as charges based on the length of a call are replaced by those based on the amount of data transferred, and by micro-payments for goods and services.

A report published this week by researcher Analysis said that some networks have opted to modify existing mechanisms to reduce costs, but that several have chosen new systems which will allow them to exploit opportunities offered by GPRS and third-generation services.

"As operators launch GPRS and experiment with a range of services and pricing options, they are demanding far greater functionality and flexibility from their billing and customer care systems," said report author Katrina Bond.

She added that mobile operators require systems that are capable of charging for a wide range of events and types of content. They also need to consider revenue sharing and billing on behalf of third-party content providers and mobile virtual network operators.

The latter have already begun to emerge on existing GSM mobile networks from the likes of Virgin, Carphone Warehouse, British Gas and Sainsbury's. Each has its own branding and customer service, but the backbone is provided by one of the four major networks.

This trend is creating demand for mobile companies to bill at different rates for both their own customers and those of the virtual network, a move for which existing telecoms and data billing systems were simply not designed.