By Richard Martin

Beefing up its offerings for cable operators, equipment vendor Sonus Networks said it has added a fixed-mobile convergence (FMC) application to its ASX application server. The new application allows cable subscribers to add multiple devices to their landlines so that calls to the fixed line ring through to their smartphones.

Users can add up to five SIP-enabled devices, including 3G/Wi-Fi enabled smartphones. The new application was demoed at the CableLabs Summer Conference in Keystone, Colo.

For several years a much-hyped buzzword among service providers, FMC has lost some luster as powerful smartphones like the iPhone and Android-based devices have, for many people replaced their landlines altogether. The advent of Web-based telephony programs like Google Voice and Phone.com have also enabled users to achieve many of the benefits of FMC without a dedicated application.

Business users, however, remain committed to systems that enable FMC, and Sonus is betting that cable customers will appreciate the chance to easily receive and make calls using their fixed line on any device. MSOs are looking for ways to add more value for fixed line customers, and also get more involved in offering mobile services,” said Greg Zweig, director of access product management at Sonus Networks, in a statement.

Sonus has been on something of a roll in 2010, even as larger rivals have stumbled. The companys share price has risen by more than half since early February, and with its negligible debt and more than $350 million in cash reserves, the vendor has become the subject of acquisition rumors specifically by Cisco.