Cicero Networks has launched a platform that could enable smart phone users to roam between Wi-Fi hotspots and cellular networks without dropping their voice calls. Cicero's offering is unusual in this space because fixed line carriers wishing to offer the converged service to users won't need to forge partnerships with mobile operators, which may see such converged services as a threat to their main revenue source.

The offering has two components: software for smart phones and a backend controller. The software can be downloaded to Windows Mobile smart phones. When customers dial a phone call using the software, it identifies which networks are in range. If a free hotspot, such as one a customer might have at home or in the office, is available, the software will route the call over Wi-Fi. Without a Wi-Fi network in range, the software will route the call over the cellular network.

Cicero, based in Dublin, is showcasing the product on HTC's Qtek 8310, a smart phone that includes Wi-Fi and GSM (Global System for Mobile Communications) connectivity.

The controller, which the company expects to release in mid-December, is deployed by an operator that offers the service to end users and handles intelligent routing and quality of service functions. The controller connects to a SIP gateway in the operator's network, and helps support handoffs between the Wi-Fi and cellular networks.

When a call starts out using a Wi-Fi hotspot, for example, the Cicero platform regularly polls the strength of the Wi-Fi connection. When the signal reaches a certain weakness, the software on the phone requests that the controller initiate a call handoff. The controller then calls the GSM radio in the user's handset, establishing a GSM connection between the handset and the controller. Once that call is connected, the software on the phone switches the call from the Wi-Fi radio to the GSM radio. The connection between the controller and the person being called remains the same throughout the process.

Key to the offering is that a wireline operator doesn't have to team up with a cellular operator to deliver the service. "In order to do that handover, you don't need the cellular operator's involvement," said Ross Brennan, chief executive officer of Cicero.

He expects that operators that decide to offer the service to end users are likely to target enterprise customers. "Purchasing managers understand that cellular telephony is a big pain point," he said. A converged product like Cicero's can cut calling costs by routing calls inside the corporate campus as well as at conferences or other public places over a Wi-Fi network rather than a cellular network, which is often more expensive to use.

Brennan envisages that a wireline operator might sell a subsidised handset to end users. The handset can either have the software pre-installed or users can download it from the operator's Web site. The user must also have a SIM card to access a cellular network, and a VoIP service, both of which could come from the wireline service provider.

Brennan said that somee operators in the US and Europe are testing the offering but he couldn't reveal which.

"In general, I agree that these services are going to be a real lifesaver for wireline carriers," said Caroline Gabriel, research director at Rethink Research Associates. Such an offering can boost revenue for fixed line operators because the Wi-Fi portion of the service will be carried across their networks.

The service won't work with Skype, and that's just as well for Cicero's target customer. Because Skype uses a proprietary protocol, third party companies like Cicero can't deliver calls through Skype. "Service providers aren't particularly keen on enabling Skype," Brennan said. "They're more keen on enabling what we have so they can provide something that is more compelling than Skype."

Some mobile operators have shown interest in the UMA (Unlicensed Mobile Access) standard, which allows the mobile operator to control and charge for calls whether they are made over Wi-Fi networks or cellular networks.

UMA is seen by some experts as an interim technology that works well with legacy cellular networks but in the future is likely to be replaced by SIP-based offerings that take advantage of all-IP backend networks, said Gabriel.

Several companies have emerged recently to deliver such converged offerings, some using the UMA standard and others leveraging SIP. Earlier this week, Stoke introduced itself as a company developing a fixed/mobile convergence platform. Other players include Kineto Wireless, BridgPort Networks and Tatara Systems.