How does Unicom use SMS to open idle traffic?

Different provinces in China have different ways to open idle traffic packets through SMS. Tianjin Idle Traffic Package charges 10 yuan Package 1GB local traffic, which can be used from 23: 00 every day to 8:00 the next day, and you can enjoy the traffic discount. Traffic charges outside the package, during busy hours and outside the province are charged according to the package traffic you choose. The time-free traffic package is applicable to users who rent 3G packages in 36 yuan and above every month. If you need to open it, you can send KT3GXS 10 to 100 10 to open it immediately. You can call 100 10 to learn how to open a free traffic package in other provinces by SMS.