The company estimated this by comparing the data from carriers worldwide and global population of nearly 6.9 billion people, as estimated by the US Census Bureau.
In 2000, there were 720 million wireless subscriptions. Most of the recent growth comes from developing countries like India and China.
In developed countries like the US, the number of new cell phone subscriptions has fallen drastically in the last six months.
Carriers are hoping to keep growth going by enticing more people to use multiple wireless devices, like e-book readers, tablet computers and Internet-connected GPS units.