What is an upgrade package in the SMS era?

1. Literally, according to the time when your mobile phone number is online, you will send 500 text messages every month after meeting the requirements.

This means expanding the capacity to 500 minutes of voice. On the Internet, the voice function must be upgraded before it can be extended.

Generally speaking, it means that voice can be sent for a longer time. Soluble speech means that its volume has been deducted and many people can hear it.