"Before VoLTE's arrival, 3G and 4G operators worldwide kept the legacy 2G networks because they needed it for voice [transmission]," Lai said. "Now that VoLTE enables voice traffic over 4G networks, operators can eventually phase out 2G and free up spectrum resources."
China Unicom started its VoLTE trials early this year, while China Telecom planned to launch VoLTE by the end of next year.
As of May 31, China Mobile had 409.316 million 4G subscribers out of a total user base of 835.406 million.
China Unicom had 68.182 million 4G users out of 260.117 million mobile subscribers in the same period. China Telecom, which recorded 205.51 million total mobile subscribers at the end of May, counted 84.55 million 4G mobile users.
David Dai Shu, spokesman for Shenzhen-based telecommunications equipment manufacturer ZTE, said expectations are rife that "China could accelerate the roll-out of 5G mobile services" to support high-bandwidth applications like augmented reality and virtual reality, which 4G networks would be hard-pressed to handle as demand grows.
Bernstein's Lane said initial mainland 5G deployments could be small, citing China Mobile's recent equipment test at The Bund in Shanghai as an example.
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