The more powerful phones are rapidly replacing the simpler, less voracious devices in many countries, raising traffic levels and pressure on operators to keep pace. In countries like Sweden and Finland, smartphones now account for more than half of all mobile phones, Mr. Zarandy said. About 35 percent of Finns also use mobile laptop modems and dongles, or modems in a USB stick; one operator, Elisa, offers unlimited data plans for as little as 5 euros, or $6.40, a month.

As a result, Finns consume on average 1 gigabyte of wireless data a month over an operator’s network, almost 10 times the European average. As more consumers buy smartphones, the level of mobile data consumption and congestion will rise in other countries.

“This of course is bad news for operators because it means that more traffic is coming and they need to invest to stay ahead of the curve,” Mr. Zarandy said.

Mr. Flanagan at Arieso said one European operator, which he declined to identify, last year installed 250 miniature base stations, called microcells, to handle the traffic of extreme users. The operator, he said, did not wish to publicize the work because it did not want to draw attention to the strains that its network was experiencing.

Patrik Cerwall, the head of strategic marketing and intelligence at Ericsson, which is based in Stockholm, Sweden, said most operators were beginning to look for ways to make their networks more efficient, whether by dumping data quickly into a fixed-line network, imposing volume limits on customers or installing miniature base stations at congestion points.

Ericsson expects the volume of global mobile data to rise tenfold from 2011 to 2016.

The rate is likely to accelerate as more consumers integrate the mobile Web into their daily lives. Last year, for example, 40 percent of smartphone owners in an Ericsson survey used their devices to gain access to mobile broadband connections even before getting out of bed.

The heaviest users of mobile data, according to Ericsson, watched videos 40 percent of the time, surfed the Web an additional 20 percent, and used up the rest of their online time in e-mails, social networking, file sharing and software downloads.