France's space agency the Centre National d'Etudes Spatiales (CNES) will put its engineering expertise to work on Google's Project Loon in return for help from the search company on its own balloon projects.

Google and the French government have recently been at loggerheads over issues like privacy and copyright, but the pair have teamed up on Loon, agreeing on an exchange of expertise that should deliver mutual benefits.

Google's Project Loon is one way Google's X team thinks it can tackle broadband connectivity constraints in remote and rural areas of the world. Since 2013, it's launched Loon air balloons in Australia, Brazil, and New Zealand, delivering web traffic through its balloon network via a relay to mobile operator-owned base stations on Earth.

In a joint statement, Google and CNES said the collaboration will allow them to pool resources and research.

CNES will help Google with balloon flight analysis and the development of next generation balloons.

"It is a unique experience for CNES to work with a leading light of Silicon Valley like Google. Collaborations like this bring down barriers and spawn new cross-disciplinary projects. We are proud to be providing our expertise while benefiting in return from the assistance of such a great global company," said CNES president Jean-Yves Le Gall.

Google for its part will help CNES conduct "Stateole-type long-duration balloon campaigns" on a larger scale than the agency has done in the past.

"Internet connectivity can improve lives, but more than 4 billion people still don't have access today," said Mike Cassidy, Google's vice president in charge of Project Loon.

"No single solution can solve such a big, complex problem. That's why we're working with experts from all over the world, such as CNES, to invest in new technologies like Project Loon that can use the winds to provide internet to rural and remote places."

Internet balloons, however, may not have the biggest impact on delivering broadband to the most underserved parts of the world, according to Ericsson's CEO Hans Vestberg.

Asked by ZDNet about Project Loon at Ericsson's headquarters in Stockholm last week, Vestberg said 92 percent of the world would ultimately get online through standard technologies such as 4G, which would help drive down the cost of internet access. The biggest challenge in delivering broadband to the last eight percent of the world is power, the CEO said.

"I see the largest challenge here being the power grid. How are you going to handle the power grid for the last eight percent? Remember there are one and half billion people who don't have power or electricity in the world. And that of course is inefficient with diesel - it's too expensive for the last eight percent. There are other things you can think about other than Loon, but that could be part of it," said Vestberg.

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