Is the children's watch card optional?

Children's smart watches need a calling card, and the smart wearable card provided by the operator is called 1 1 bit IOT voice card, which has the functions of calling and traffic, and no SMS. 20 17, children's watches mainly use Unicom IOT voice card. Since the second half of 20 18, Unicom has switched to mobile IOT voice card after shutting down the 2G network. In addition to the mobile 2G network, the signal is also the most stable among the three operators. The voice card of IOT is produced by the operator, and the service provider is directly responsible for selling the terminal. Neither the service hall of the operator nor the official website can be consulted, so it is not affected by the outside world to ensure the safety of children.