Huawei, a leading global information and communications technology (ICT) solutions provider, and Qualcomm Incorporated have completed an LTE FDD flash CSFB (Circuit Switched Fallback) voice call to UMTS using R9 protocol and Qualcomm’s latest Snapdragon™ S4 processor, the MSM8960, during a series of optimization tests.

The tests, based on the flash CSFB voice solution for the R9 protocol, resulted in lower call setup latency than that of the R8 protocol, and very close to that of a native UMTS voice call. During the CSFB testing, which also included LTE TDD calls, good call setup times were seen for both UMTS and GSM.

LTE networks have already met users’ need for higher speed mobile broadband data services. The introduction of R9 CSFB will further enhance users’ experiences and enable high quality voice services on their LTE-based smart phones, through CSFB to GSM and UMTS. CSFB is an industry standard voice solution that enables LTE devices to fully utilize existing 2G/3G networks for voice and SMS services.