Is global telecom revenue growing, flat or shrinking? It turns out analysts disagree. Researchers at Ovum think global telecom revenues will remain roughly flat over the next few years, with a decline in spending on voice services counterbalanced by growth in spending on mobile and fixed (broadband) data services.

Gartner researchers however, expect 4.3 percent revenue growth, globally, for 2013. While, IDC is forecasting low single digits revenue growth.

Those service provider revenues will be unevenly distributed, growing in most regions, but shrinking in Europe.

What is clear is the rapid growth of mobile usage and revenues, notably with European weakness. In 2001, there were about one billion mobile phone subscribers in total, most of them in developed countries. By about 2012 there were six billion subscribers, and 73 percent of those (4.4 billion) were in developing countries that account for just 20 percent of the world’s total gross domestic product.

In just 10 years, mobile phones have almost reached saturation point in countries where people earn just a few dollars per day. Smartphone adoption is following a similar sort of trajectory.

In 2009, the Asia-Pacific region had 86 million smart phone users. In 2013, 738.2 million smartphone users. By way of comparison, that means the Asia-Pacific region has more than four times as many smartphone users as the next largest region, Western Europe, which will have 161.1 million by the end of the year, and North America, which will have 152.2 million.

Furthermore, nearly 2.5 billion of the world’s 4.3 billion mobile phone users in 2013 will be in the Asia-Pacific region, according to research firm eMarketer.

It estimates that 2.43 billion people in Asia-Pacific will use a mobile phone at least monthly in 2013, representing 56.3 percent of the world’s mobile phone users.

More than one billion of these mobile users will be in China alone, and about half that number will reside in India. By 2017, eMarketer estimates, Asia-Pacific will have nearly three billion mobile phone users out of a total 5.10 billion across the globe.

So smart phones might be the fastest-adopted technology in human history.

Mobile phone usage is growing exponentially in the Middle East and Africa as well, with Africa expected to become the second-largest mobile phone region, after Asia.

In the Middle East and Africa, 525.8 million people use a mobile phone at least monthly. .

Smart phone use in the region will nearly double to 112.2 million, up from 67 million in 2012, while penetration of smartphones among the population as a whole in will increase from 5.1 percent to 8.3 percent.

We’ll have to wait and see though, whether global revenue actually remains flat, or grows.