Cristiano Amon, Qualcomm: VoIP-over-LTE Hurdle Cleared

February 02, 2012

Qualcomm working with Ericsson, has successfully completed the first voice call handover from an LTE mobile network to a WCDMA network using Single Radio Voice Call Continuity (SRVCC). An important technology required for voice-over-LTE (VoLTE) support, SRVCC is a 3GPP specified feature that enables continuity of service by seamlessly switching to a WCDMA network when a consumer on a VoLTE call leaves the LTE network’s coverage area. This milestone occurred on December 23, 2011 with an Ericsson network using a handset which incorporated Qualcomm’s Snapdragon S4 MSM8960 3G/LTE multimode processor. A demonstration will be available at Qualcomm’s booth at Mobile World Congress in Barcelona, Spain February 27 – March 1, 2012.

“As LTE networks are deployed alongside 3G networks, the ability for multimode 3G/LTE mobile devices to connect to different network technologies will be an important part of providing the best possible mobile voice and data experience to consumers,” said Cristiano Amon, senior vice president of product management, Qualcomm. “Qualcomm is committed to the successful deployment of LTE networks worldwide in conjunction with 3G networks, and the milestone we’ve achieved with Ericsson is another step towards making VoLTE technology a commercial reality.”

SRVCC is the next logical step in the 4G LTE voice roadmap following the commercial launch of circuit-switched fallback technology (CSFB) on smartphones in 2011. CSFB allows a single radio in the handset to dynamically switch from an LTE data connection to a 3G connection when the user needs to make or receive a call. Similarly, SRVCC support enables a single radio in the handset to execute a seamless handover of a voice call from an LTE network to a 3G network. Furthermore, SRVCC and CSFB allow both LTE and 3G network connections to be supported on a single chip, eliminating the need for smartphones to use separate LTE and 3G radios and modems. This allows OEMs to design handsets with lower power consumption and component costs and a smaller size. Given that 3G networks will continue to be deployed in conjunction with LTE networks for quite some time, SRVCC and CSFB are essential to provide a seamless voice experience to customers using LTE multimode handsets once VoLTE is commercially deployed. Qualcomm is committed to ensuring the best voice performance to users in LTE networks through industry-leading CSFB and SRVCC technologies.