Japan provides the slowest LTE high-speed wireless cellphone service among nine countries with advanced telecommunications networks, according to a study of download speeds.

Sweden ranked at the top in average bandwidth speed with 22.1 megabits per second on its 4G network, while Japan brought up the rear with just 7.1 megabits, according to the study by OpenSignal Inc.

Hong Kong came in second with 19.6 megabits, followed by Denmark with 19.1 and Canada with 18.1. The United States came in second to last with only 9.6 megabits per second.

"The countries where we recorded the fastest average speeds tend to be ones where the population is heavily concentrated in a small number of urban centers," OpenSignal said.

Among Japan's carriers, the study found that Softbank Corp. delivered the fastest service — 16.2 megabits per second — via its long-term evolution network, followed by KDDI Corp. with 14.8. NTT Docomo Inc. logged a mere 5.5 megabits.