“eSIM One Phone Number Multi-Terminal (一号多终端)” means that one phone number can shared with the user’s smartphone and wearable devices, without the need for a physical SIM card. For example, using eSIM users can go out exercise without carrying an additional mobile phone; the data recorded by the watch can be synchronized to the phone in real time.
Apple Watch 3 was the first end-product to support the eSIM. Last year November, this caused connection failure problems as Chinese carriers were not ready, and one month later Apple decided that Apple Watch Series 3 customers are eligible for a refund in China. The problem was that the eSIM allows users to subscribe to any carrier they choose and thus loosening the government’s ability to tracking users. The previous two generations of Apple Watch must be connected to the iPhone via Bluetooth to receive calls. Now that China Unicom also launched eSIM, Apple Watch 3 users can independently access the mobile cellular network.
China Unicom is currently the only operator that launched eSIM business in China, and made its first eSIM wearable product after two years’ work. From this date until December 31, 2018, China Unicom users who initiate this service can pay a lower fee on secondary eSIM card, from the activation date to 12 months later.