After testing the waters with consumers for more than a year, BT Group plans to extend its converged fixed-mobile communications service to businesses early next year. The move follows a successful field test with a government organization.BT Corporate Fusion, announced Thursday, combines Wi-Fi and mobile phone service for voice calls, using voice-over-IP (VoIP) technology when calls are made over a wireless network to lower phone costs.The service will be rolled out initially in the United Kingdom\u00a0and Italy early next year, with Germany, France, Spain and the Benelux countries to follow. The operator plans to announce handset deals in the coming weeks.The new service works like this: Calls made from dual-mode Wi-Fi-GSM (Global System for Mobile Communications) phones within an office building are connected through Wi-Fi access points and routed over existing fixed-line infrastructure. Using VoIP technology to route those calls saves money.Outside corporate premises, the dual-mode phone operates like a mobile phone, providing ubiquitous coverage and global roaming. These calls, however, are more expensive because they are carried over mobile phone networks.The Leeds City Council has been testing the new converged service at two locations. Several operators, including Deutsche Telekom and the Danish subsidiary of Sweden\u2019s TeliaSonera, have launched new converged fixed-mobile services, but these offerings are targeted at consumers, largely in a move to keep customers from abandoning traditional fixed-line telephone service.On Thursday, BT also said the group expects to more than double revenue from networking services for enterprises in the United States, Japan, China and India. The company did not pen a number to its prediction.-John Blau, IDG News Service (Dusseldorf Bureau)Related Link:\n\nBT Reveals Plans for All-IP NetworkCheck out our CIO News Alerts and Tech Informer pages for more updated news coverage.