China Unicom and equipment supplier ZTE announced they completed a 5G call with the vendor’s 5G prototype smartphone in a commercial field trial in Shenzhen.

In a joint statement, the two said the call was a world’s first using non-standalone (NSA) mode, which is compliant with 3GPP Release-15.

They said the test also completed the verification of services including WeChat group voice call, online video and web browsing.

The trial used ZTE’s end-to-end network equipment, which included its radio access network, core network, transport network and intelligent device.

Shenzhen, one of the operator’s first 5G pilot cities, is verifying the 5G network equipment’s networking capabilities, special services, roaming and interconnection in phases.

China Unicom and rivals China Mobile and China Telecom are involved in third-phase 5G tests for core network performance stability and security function. Under the guidance of the Ministry of Industry and Information Technology, the IMT-2020 (5G) Promotion Group initiated third phase 5G R&D tests in November 2017.

The 3GPP approved the NSA 5G New Radio specification in December 2017.