New Chip Boosts Battery Life, Improves Call Quality

The two companies demonstrated a successful mid-call switch from a VoLTE network to a 3G one in late December, using a 3G LTE-based smartphone with a Snapdragon S4 processor. The success of the Qualcomm-Ericsson demonstration hints future handsets will combine 3G and Voice over LTE technologies, enabling a single processor to shift between 3G and 4G LTE networks without dropping calls.

The in-call switching capability stems from two relatively recent advances, single radio voice call (SRVCC) continuity and circuit-switched fallback technology. CFSB is in today's handsets and enables users to switch from 4G data streaming to make calls using more commonly available 3G CDMA networks.

However, phones on the market need two "radios" to handle both older, 3G CDMA networks and the newer, faster LTE networks that give the "true" 4G speeds today's data-hungry consumers demand from smartphones. The newer SRVCC technology demonstrated enables a single "radio" in a cell phone to shift calls between 3G and 4G without drops or interruptions.

This capability will allow devices to seamlessly drop back to 3G on voice calls in areas where 4G LTE network coverage is spotty, and to handle both data streaming and voice calling simultaneously without the battery drain issues common in many LTE handsets on the market today.

The call handover technology will also make VoLTE more widely available, which will help reduce strain on 3G networks and pave the way for carriers to begin using advanced voice-call technology, even in areas where they lack high-speed coverage.

This capability holds promise for wireless carriers, particularly Verizon, which is testing Voice over LTE in two U.S. cities and expects to roll it out nationwide in 2013.

The nation's number-one carrier also aims to make all its smartphones LTE devices moving forward, and this new call-switching technology may help it achieve that aim, because it will enable handset manufacturers to produce devices that can easily accommodate both 3G and 4G for voice calls, without doubling up processors, increasing the size of the devices or overtaxing the batteries.

Seamless call handover will also allow Verizon to guarantee better call quality as it rolls out Voice over LTE, because its next generation of smartphones will likely be able to fall back to 3G CDMA mid-call in areas where VoLTE hasn't been rolled out yet.

"As LTE networks are deployed alongside 3G networks", said Cristiano Amon, senior vice president of product management at Qualcomm in a statement, "the ability for multimode 3G/LTE mobile devices to connect to different network technologies will be an important part of providing the best possible voice and data experience to customers".

Qualcomm plans to repeat the call handover demonstration at the Mobile World Congress in Barcelona, Spain later this month.