ZTE and German operator E-Plus are planning to launch a commercial VoLTE service, after jointly deploying a core IMS network infrastructure.
The service has been in testing for some time although the operator refused to reveal when VoLTE would go live to its customers.
Li Jun, CEO of ZTE Deutschland, said: "We are very honoured to provide IMS network and VoLTE solutions for E-Plus. ZTE's VoLTE solution will help E-Plus to provide high-quality voice services and guarantee high-bandwidth data services based on LTE access, [as well as] help improve E-Plus's network profitability."
VoLTE offers superior voice quality to standard circuit switched fall back (CSFV), where voice services “fall back” onto 3G or 2G networks, as it offers more capacity and requires less bandwidth.
Additionally, enhanced single RAN voice call continuity (eSRVSS) flow allows voice service to be smoothly switched to the 3G network when there is a gap in 4G coverage.
In March, the Global mobile Suppliers Association (GSA) announced that 100 operators in 71 countries have now launched HD voice services.
Vodafone UK held its first VoLTE trials in August, meanwhile its Dutch arm announced it hoped to begin testing by the end of the year with the aim of rolling out the service in 2015.
Alan Hadden, President of GSA, said: “Approaching 1 in 5 HSPA operators now offer HD voice service [and] the choice of HD phones more than doubled over the past 12 months. Market momentum is positive for mobile HD voice, and growing.”