Benefits of converged technologies

The result of all this technology is that users can eventually have a single phone that converges cellular, fixed and mobile VOIP. One market segment in which that idea will be particularly attractive is health care, where doctors and nurses in large facilities such as hospitals spend much of their day walking around visiting patients and colleagues and attending meetings. As in the warehouse scenario mentioned earlier, in-building cellular coverage can be spotty and, besides, VOIP is less expensive. As a result, many health care organizations already have given medical personnel voice-over-WLAN phones, and phones that combine cellular and VOIP would have obvious attractions.

In order for the vision of voice convergence to work, however, technology is needed to hand off calls between cellular and IP-based networks. Here, too, new technologies are emerging. The two with the most momentum are Unlicensed Mobile Access and IP Media Subsystem (IMS). In simple terms, the former technology is for use with GSM-based cellular networks such as those deployed by Cingular and T-Mobile in the U.S., while IMS is IP-based and uses SIP technology already commonly in use with fixed VOIP systems.

Technologies like these are essential for the vision of mix-and-match cellular and VOIP calling to work. Cellular operators and cell-phone manufacturers must incorporate technologies such as these into their infrastructures and phones before these transparent handoffs between networks can occur. The phone manufacturers, which ultimately will sell phones no matter what type of network is used, have been testing the technology and pushing carriers to adopt it. Similarly, vendors of infrastructure equipment used by cellular operators, such as base stations, have also been testing the technology. The carriers, however, have been less than eager, since the change would tend to migrate cellular minutes to VOIP. And that potentially would bring in a slew of new competitors.

The missing business models