German telecommunications service provider Deutsche Telekom on Thursday launched a bundled service that combines mobile phone and Wi-Fi telephony services, targeting customers who seek attractive fees and greater mobility.The converged T-One offering from T-Com, Deutsche Telekom\u2019s fixed-line unit, features a new dual-mode phone, which allows users to make wireless voice-over-IP (VoIP) calls within their homes or public hot spots and cellular calls outside of these areas.The German telco follows BT Group, which last year launched one of Europe\u2019s first converged services, called Fusion. The service, which initially used Bluetooth short-range wireless technology to connect to BT\u2019s broadband network, now includes Wi-Fi.Last month Nokia, the world\u2019s largest handset maker, began testing Unlicense Mobile Access technology, which lets users make calls on both cellular and Wi-Fi networks and switch between networks without interruption.Nokia\u2019s new 6136 phone automatically transfers voice or data connections from Global System for Mobile Communications (GSM) networks to Wi-Fi when the device recognizes a compatible wireless network. And vice versa, when users make a call or data transfer via Wi-Fi and step out of the Wi-Fi network\u2019s coverage area, the connection is transferred to a GSM link without interruption.The T-One offering is based on session initiation protocol, instead of UMA, according to a T-Com spokeswoman.T-One systems include a digital subscriber line connection, wireless LAN router, dual-mode cellular and Wi-Fi phone. Customers must pay, among other fees, a monthly fixed-line connection and DSL flat rate.For Wi-Fi telephony service, they can purchase either a VoIP flat rate or volume package, according to the spokeswoman. "The VoIP offering is by far the most attractive," she said.For the cellular service, users can choose among several options, including a 25-minute package for 10 euros (US$13) and a 200-minute package for 38 euros, with each additional minute costing 0.39 euros.By John Blau, IDG News Service (Dusseldorf Bureau)Check out our CIO News Alerts and Tech Informer pages for more updated news coverage.