The combination of 3G and smartphones has made it easy to place a video call, so the number of smartphone video call users is bound to reach 29 million by 2015, according to market research firm Juniper Research.

However, the researcher warned, the video calling will not become a mass-market technology in the next five years as interoperability between different devices is likely to hold back its immediate uptake in the global market.

The launch of Apple's (News - Alert) FaceTime video calling feature with the iPhone 4 will give some impetus to the market for video calls over smartphone devices, but there are many hurdles still standing in the way of growth, said the researcher in its report titled "Next Generation Smartphones: Strategic Opportunities and Markets, 2010-2015."

"The use of video calling has had several false dawns and has remained flat in recent years," said Anthony Cox (News - Alert), senior analyst. "We forecast that there will be 29 million smartphone video users in 2015, but the market may be held back by a lack of interoperability between different devices."

Apple's latest handset, the iPhone (News - Alert) 4, lets its users make video calls using its FaceTime app. It works only with other iPhone FaceTime users and only over a Wi-Fi connection.

"In the longer term, the growth of WiFi (News - Alert) and 3G in developing markets may make video calling an attractive option for international calls for those working and living away from their families," the researcher added.

However, 3D functionality and dual core processors are among several technical developments which will drive the market forward over the next five years.

Functionality associated with today's smartphones, such as app store connectivity and touchscreens, will be present in over 84 percent of handsets shipped in the U.S. by 2015.

Analysts have often predicted that video call-enabled gadgets and TVs eventually make such communications as common as texting. They remind that it is the video call that has made Skype, the Internet-based voice and video chat service, popular.

According to the researcher, the value of global smartphone device shipments will reach $94 billion in 2015.

Additionally, the researcher said, recent developments, like the resignation of Meego's head Ari Jaaksi, and the decision of both Samsung and Sony Ericsson (News - Alert) to abandon Symbian will further boost the position of the Android operating system in the smartphone market over the next five years.

In the meantime, barriers to entry for consumer electronics players have reduced as operating systems have become open source and the component market has become increasingly standardized.