Smartphones and tablets have provided video calling features and apps for some time now. Built-in applications such as Apple's Face Time and third-party app Skype have enabled visual communication over wireless networks, and the increase in popularity of tablets has made video calling a more rewarding visual experience.

In the last few years, video calling over cellular networks has become possible, if not yet financially comfortable. Users who are only interested in making basic phone calls think of the smartphone as the preferred conduit for talk and text.

There is a growing trend in Asia, and so far nowhere else, to use an Internet-connected tablet as a telephone, in place of the more traditional hand-held smartphone.

This may seem ungainly, to hold a tablet with a 7-inch or larger screen as one would a telephone, but mostly in the interests of device consolidation, Asian users are more often relying on their tablets to double as cell phones. As tablets become lighter and thinner, the trend should continue.

The popularity of the "phablet," a cell phone with a large-enough screen to border on tablet-size status, is leading to consumer acceptance of the concept of a big-screened cell phone. As smartphone screen sizes enlarge, the idea of using a tablet in place of a smartphone for telephone functions does not seem so far-fetched. Over time, data plans for tablets have eased down in price, and data allotments have considerably enlarged. Both have helped promote data-intensive voice calling use.

Asian customers are also interested in cost consolidation, to economize on gadgets. Nor do consumers want to be burdened with carrying around multiple devices.

In a way, it's similar to another seemingly Asian-led trend; using iPads and other large tablets in place of cell phone cameras, or even traditional digital cameras.

The voice call craze has been reported in China, India, Indonesia, Malaysia and Thailand, according to Avinash Sundaram, an IDC analyst. Reports on the trend exclude Japan and Korea for the time being.

This trend is being monitored carefully by smartphone providers such as Samsung and other phone makers who are trying to figure out how to capitalize on the popularity of tablet voice calling without cannibalizing the sale of their smartphone products.

"If we look at advertising campaigns in India and Indonesia, they call it a tablet with voice option," Sundaram said. "Vendors could conceivably put cellular features into all their tablets, But bigger companies such as Samsung might refrain from doing so, to better position their smartphone products," he added.