As for why there is no 4G network, it is not clear. But it is almost inevitable that the mobile phone network is better than other places in the university town. Because there are 10 universities and 4 villages in the university town, the number of mobile phones is specific, and the data processing load of the fixed base station server in the university town is heavy. At present, data sharing only depends on mobile base stations. In addition, the signal in the teaching area of the university town is generally poor, partly because of the service base station and partly because the school has interference signals. Finally, you can make phone calls in class, but it's up to you to surf the Internet.