A government auction of airwaves for use in mobile broadband has blown through presale estimates, becoming the biggest auction in the Federal Communications Commission’s history and signaling that wireless companies expect demand for Internet access by smartphones to continue to soar, Edward Wyatt reports. Companies bid more than $34 billion as of Friday afternoon for six blocks of airwaves, more than three times the $10.5 billion reserve price that the commission put on the sale. Prices are likely to rise, because the auction could continue for days or weeks.