Deutsche Telekom and Wi-Fi provider Fon are to roll out 2.5 million new Wi-Fi hotspots in Germany by 2016.

The hotspots will form the largest Wi-Fi network in Germany and will support Deutsche Telekom’s WLAN TO GO offering, in which users share their home Wi-Fi with other users in exchange for access to millions of hotspots around the world, free of charge.

“The partnership with FON fits perfectly with Telekom’s network expansion strategy. The astonishing increase in data traffic calls for network optimisation and expansion, as well as the implementation of new high-speed networks,” said Deutsche Telekom CEO René Obermann.

The tie-up with Fon is part of Deutsche Telekom’s “innovation by collaboration” approach in which it aims to build alliances with innovative partners. Obermann said in his keynote at last week’s Mobile World Congress that operators need to cooperate with third parties if they are to continue to remain relevant.

Fon currently operates the world’s largest Wi-Fi network with more than eight million hotspots and nine million subscribers.

Customers share their broadband in return for hotspot access in Belgium, Croatia, France, the Netherlands, Spain and the UK. Deutsche Telekom will launch the service through its divisions in Bulgaria, Greece, Romania, Slovakia and Hungary.

Fon also operates in Brazil, where Deutsche Telekom customers using Fon will be able to access the internet for free during the 2014 FIFA World Cup.