LTE voice evolution: Phase one. "Circuit-switched fallback. The first phase of voice evolution for mobile LTE services"
As an all-IP data-only transport technology, LTE presents challenges in satisfying established quality of service (QoS) expectations for mobile telephony for LTE-capable smartphones being served on the LTE network.
In this paper, Qualcomm and Ericsson share their insights on using circuit-switched fallback, (CSFB) as a solution to this challenge. Find out more about recent deployment experiences and extensive testing that has been conducted on the first phase of voice evolution between packet and circuit-switched networks.
The paper details call setup reliability, incoming and outgoing call setup time, voice network acquisition, the network architecture of CSFB and the three phases of LTE voice and communication services evolution.
Ericsson and Qualcomm also demonstrated that CS fallback provides a satisfactory voice service experience on commercial LTE smartphones. The world's first handover of a voice call from LTE to WCDMA (SRVCC, Single Radio Voice Call Continuity) was also demonstrated at Mobile World Congress earlier this year. See the recorded demonstrations here.