Voice over Internet Protocol (VoIP) is gaining in popularity, but many incumbent mobile network operators have not shown willingness to offer the service to subscribers.

The no-cost or low-cost VoIP service has already put a downward price pressure on voice services and even basic data service. As more people become aware that Internet Protocol (IP) is a cheap source of transport, the demand for VoIP and therefore Over the Top (OTT) VoIP alternatives will rise in the immediate future, according to recent findings from Research and Markets’ "Market Opportunity: Free VoIP over Wireless vs. VoLTE" report.

This report analyzes the current OTT Wireless VoIP service providers by evaluating the market prospects relative to the incumbent wireless carriers. It says wireless VoIP is a catalyst for growth incumbent operators to take action.

There is an opportunity for certain OTT VoIP providers to be acquired by incumbent wireless carriers. The report evaluates the transition strategy for mobile network operators to partner/acquire certain OTT providers as a means of positioning the former towards "dialable" VoIP via VoLTE, and also an offering for support of outbound roaming in non-LTE (News - Alert) areas.

Research and Markets analyzes key Value-added Service (VAS) capabilities that can be offered through VoIP. Particularly the research focuses on services such as presence, and one of the key presence-enabled VAS applications, Dynamic Address Book (DAB).

The report finds that incumbent operators are in the best position to leverage presence and other core network capabilities. The DAB, along with other presence and location based applications, is key to incumbent carriers’ success in differentiating themselves from OTT competitors, according to the Research and Markets report.

Recently a research from Point Topic highlighted that VoIP has more than 120 million subscribers worldwide. The VoIP market is set to generate $40 billion annual revenue by 2015, according to Point Topic. VoIP market grew 12.6 percent during 2010, but there are more opportunities left for VoIP around the world.

Want to learn more about the latest in communications and technology? Then be sure to attend ITEXPO West 2011, taking place Sept. 13-15, 2011, in Austin, Texas. ITEXPO (News - Alert) offers an educational program to help corporate decision makers select the right IP-based voice, video, fax and unified communications solutions to improve their operations. It's also where service providers learn how to profitably roll out the services their subscribers are clamoring for – and where resellers can learn about new growth opportunities. To register, click here.