What happened when 4g became 2g?

There are two reasons why 4g becomes 2g: 1. There is no 4G signal coverage nearby or the signal is poor, but there is 2G signal coverage. The mobile phone can only access the 2G network, only in the deserted wilderness or high mountains. This may exist in certain regions; 2. If the user does not activate VoLTE, making or receiving calls will fall back from 4G to 2G.

The operating environment of this tutorial: MIUI12.5 system, Xiaomi 11 mobile phone.

What happened when 4g changed to 2g?

If you see that your mobile phone signal has changed from 4G to 2G, generally speaking, there are only two possibilities:

1. There is no 4G signal coverage nearby or the signal is poor, but there is 2G signal coverage, and the mobile phone can only access the 2G network. Nowadays, the level of optimization of 4G network construction is already high, especially in places where a large number of users gather, such as cities, counties, and villages; this situation may only exist in desolate wilderness and high mountain areas.

2. If the user does not activate VoLTE, making or receiving calls will fall back from 4G to 2G. This technology is called voice fallback (CSFB).

4G LTE is a fully packet-switched network. In other words, this network does not support voice calls. When voice services occur, the network needs to switch to 2G to support voice signal exchange.

VoLTE can essentially be understood as a service similar to WeChat Voice, which converts voice signals into data packets and then transmits and exchanges them through the LTE bearer/core network.

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