Swisscom said it is the first operator in Europe to combine voice-over-LTE (VoLTE) with Wi-Fi calling to overcome weak mobile signals in heavily insulated buildings.
The operator launched its Wi-Fi calling service in Switzerland and Liechtenstein on Thursday and said it planned to extend the service to other countries over time. The Wi-Fi element forms part of the operator's Advanced Calling service, which it announced in June when it launched VoLTE in the same two countries.
Marc Werner, Swisscom's head of residential customers, said it plans to launch Wi-Fi calling in other markets "over the course of the coming year."
The service automatically switches subscribers to Wi-Fi networks if the signal is stronger than their mobile reception. Swisscom said that can help to improve mobile phone battery life by eliminating the process of switching between 2G, 3G and 4G networks, and that making calls over Wi-Fi would not affect users' web browsing speeds.
Swisscom is offering Advanced Calling to subscribers on its Natel packages, and said Wi-Fi calls are charged at the standard mobile calling rate.
Werner said the rollout of Advanced Calling in other countries would boost the value of Swisscom's Natel Infinity plus subscriptions, which already offer "between 30 and 365 days of unlimited calls per year" to users roaming in other European Union markets.
While the company is working to deploy the Wi-Fi service to all Natel subscribers, it is presently only available to customers with a Samsung Galaxy S6 edge smartphone. Swisscom said it would expand availability to other smartphones by the end of the year.
The operator last week said it plans to launch an upgraded LTE network offering data rates of up to 450 Mbps by the year end as part of a push to match growing demand for mobile broadband services. The volume of mobile data transmitted on the operator's network in the opening half of 2015 doubled compared to the same period of 2014, it said.
Swisscom also plans to launch three-carrier aggregation combining LTE FDD and TDD modes in a commercial network by summer 2016, following a recent demonstration run in conjunction with Ericsson and Qualcomm in Zurich.
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