Cellular carriers seek smooth handoffs from LTE to 3G

February 09, 2013

Mobile engineers have successfully demonstrated the handoff of a voice call from LTE to 3G, a capability that may prove critical in carriers' plans to put voice on their new, fast data networks. Engineers from Telefonica Deutschland used SRVCC (Single Radio Voice Call Continuity) to move a call without disruption from an LTE to a 3G network. The test took place in a lab and was carried out over equipment from at least six different vendors in an effort to emulate mixed real-world networks, according to Telefonica. Keeping a subscriber's call going as they move out of an LTE coverage area will probably be important to the deployment of VoLTE (voice over LTE), a technology that breaks a voice call into packets and transmits it as data traffic. Carriers that can't fill their whole coverage area with LTE will need a way to make the handoff. SRVCC, part of the 3GPP family of standards that underlies GSM and LTE, has wide support to become that mechanism. Products from Ericsson, Huawei Technologies, Nokia Siemens Networks, Acme Packet, Qualcomm and Sony Mobile were included in Telefonica's demonstration network. However, the need for SRVCC is expected to trail demand for VoLTE itself, which is only slowly emerging. Even most carriers that have extensively deployed LTE are still transmitting voice over their older 3G networks, which are expected to remain online for many years. To read this article in full or to leave a comment, please click here

Link: http://www.pcworld.com/article/2027763/cellular-carriers-seek-smooth-handoffs-from-lte-to-3g.html