Ericsson Claims First LTE-TDD to CSFB Call
Ericsson today said that it has demonstrated the first call using LTE-TDD to circuit switched fall back (CSFB) technology in public. The call was made with Ericsson networking gear and a device using a multi-mode LTE chipset from Qualcomm. CSFB is one solution that may be used by wireless network operators to transition phone calls from LTE networks to GSM networks. CSFB allows both LTE and 3G network connections to be supported on a single chip, which lets handset makers design smaller, less expensive, more power-efficient phones that can make voice calls over LTE networks, and then switch to GSM-based networks when LTE coverage is not available. Earlier this year, Ericsson and Qualcomm used Single Radio Voice Call Continuity (SRVCC) to achieve the same effect for VoLTE-to-WCDMA handoffs. Today's announcement expands the handoff scenario from standard LTE to LTE-TDD, which is an updated version of LTE.