Hong Kong mobile operator CSL has successfully conducted a High Definition (HD) voice over LTE (VoLTE) call hand-off to 3G with an eSRVCC-based pre-commercial network. HD voice will keep service continuity before and after hand-off. All network equipment used in this demonstration was provided by ZTE. This HD VoLTE call with end-to-end QoS assurance provide highly reliable user experience and help operators differentiate their services.
The Adaptive Multi Rate Wideband(AMR-WB) speech codec was supported in the HD VoLTE call demonstration. This HD voice speech codec provides improved speech quality due to a wider speech bandwidth from 50 to 7,000Hz and ensures no significant impact on radio-frequency capacity due to the efficiency of codec suitable. HD voice technology will significant promote the development of high quality voice service, such as speech recognition, speech-to-text and HD conferencing.
“VoLTE provides an improvement in spectral efficiency and is needed to increase network capacity and allow to re-farm the 3G spectrum in the future,” said Christian Daigneault, Chief Technology Officer of CSL. “This HD VoLTE call using eSRVCC will shorten call set-up time, assure good handover to 3G where required and creates a better user experience for our customers. CSL has been the first to bring Dual Band LTE at 1800/2600 MHz in Asia and will continue to bring a superior network experience to its customers. The success of this demonstration is an important milestone in the development of LTE voice services in the mobile industry.”