The U.S. has fallen to No. 55 in LTE performance as speeds rise rapidly in countries that have leapfrogged some early adopters of the popular cellular system. The average download speed on U.S. 4G networks inched up to 10Mbps (bits per second) in the June-August quarter, according to research company OpenSignal. That was an improvement from 9Mbps in the previous quarter, but the country's global ranking fell from 43rd as users in other countries enjoyed much larger gains.
