Ericsson has said that it enabled the commercial deployment of CSFB (Circuit Switched FallBack) technology during the second half of 2011 for several LTE operators. The vendor said that it had upgraded equipment to support the 3GPP standardised functionality in "several networks" in North America, Europe and the Asia Pacific region.
"We now introduce telecom grade voice services to work in combination with the superior data connection speeds that are available in LTE smartphones for the global GSM/WCDMA market. These commercial deployments of Circuit Switched Fallback prove the market maturity of this new technology and demonstrate Ericsson’s technology leadership and commitment to helping operators launch services on the latest consumer devices," Magnus Furustam, Head of Core & IMS at Business Unit Networks at Ericsson, said.
Circuit Switched Fallback network functionality means that mobile broadband data traffic is run over LTE, or HSPA when LTE coverage is not available, while voice and SMS services are provided using GSM or WCDMA circuit-switched networks. It is designed to provide continuity and availability of voice and SMS services for users of LTE phones who are moving in and out of LTE coverage.
CSFB is a software upgrade to operators’ core and radio networks, which include circuit-switched core (Mobile Softswitch Solution), Evolved Packet Core (Serving GPRS Support Node-Mobility Management Entity or SGSN-MME) and radio access (GSM, WCDMA and LTE).
In time, many operators will move to "full" VoLTE sevices, but the easier availability of CSFB form a device and equipment perspective means many will also deploy CSFB as a stepping stone measure. That means that for quite a while, operators will be supporting CSFB and VoLTE in their networks, as users and devices are eventually ported to being VoLTE capable.
The switching on of CSFB capability essentially means that LTE operators are readying themselves for the near-term deployment of phones on LTE networks, as well as tablets and USB data dongles.