Microsoft seeking to regain its footing in the fiercely competitive mobile market is expected to unveil a new smartphone platform at the industry’s biggest trade show. The US software giant has remained tight-lipped about what CEO Steve Ballmer will announce at the Mobile World Congress in Barcelona, Spain, but analysts widely believe he will reveal an upgrade of the Windows operating system.

Microsoft has been up against strong competition from telecommunications giant Nokia’s Symbian platform and internet giant Google’s Android. “They do seem to have been pushed on to the backfoot with the Android which seems to have caught them on hoof,” said Jeremy Green, mobile analyst at research firm Ovum.

Google plans to build a fibre optic broadband network that will connect customers to the internet at speeds 100 times faster than most existing broadband connections in the US, the company announced on its corporate blog.

"Our goal is to experiment with new ways to help make internet access better and faster for everyone," two Google product managers, Minnie Ingersoll and James Kelly, wrote in the blog post Wednesday.

They said that Google plans to build and test the network in trial communities around the country starting later this year and that the tests could encompass as many as 500,000 people. They cited 3-dimensional medical imaging and quick, high-definition film downloads among the applications of such high-speed internet access.

"We'll deliver internet speeds more than 100 times faster than what most Americans have access to today with 1 gigabit per second, fibre-to-the-home connections," the post said. "We plan to offer service at a competitive price to at least 50,000 and potentially up to 500,000 people."

"We're doing this because we want to make the web better and faster to everyone," said Kelly, who also promised that the network would operate on open access network, in which users could choose various internet providers and which would not give preference to any one kind of content. Kelly appealed to local officials who were interested in having their community participate in the trial to contact the internet giant.

The announcement continued Google's recent initiative to expand into market sectors beyond its core web search speciality. In the last year it has made a splash in the mobile phone market with its Android operating system and Nexus One handset, and Tuesday announced a social networking feature aimed at taking on Facebook and Twitter.

While broadband industry incumbents may fear the entry by Google, Federal Communications Commission chairman Julius Genachowski welcomed the move, the Washington Post reported.

"Big broadband creates big opportunities," he said in a statement. "This significant trial will provide an American testbed for the next generation of innovative, high-speed internet apps, devices and services."