The three major operators have set up business halls on university campuses.

Major operators have launched campus card packages specially designed for students.

For example, a package of China Unicom now has 30G ordinary traffic and 40G directional traffic in 38 yuan every month.

SIM card is the subscriber identification card of digital cellular mobile phone, and its full name is "subscriber identification module". In GSM digital mobile phone system, SIM card plays an extremely important role.

It is not only an important part of mobile phone, but also the ID card of every GSM mobile phone user. So SIM card realizes the idea of recognizing people but not phones.