Obstacles are common for the communications industry. However, because communications are the infrastructure that supports people's lives, if obstacles actually occur, the whole of Japan will be thrown into chaos. The communication failure in NTT DoCoMo just a few days ago illustrates the seriousness of the matter.
Until recently, the "Dual SIM usage" of two kinds of SIM was used only for businessmen who needed "two phone numbers", heavyweight users seeking "high-capacity data communication" environments, and so on.
But the monthly fee for SIM fell sharply in 2021. Dual SIM operations can be easily used by anyone.
The biggest advantage of using two SIM is that you can use two lines from "docomo", "Softbank", "au" and "Rakuten Mobile". Even if there is a communication failure on the primary line, contact or payment can be made if the secondary line is connected.
If you use a smartphone for a long time, you may experience a "communication failure". No one knows how long that will take. Everything is like this, as long as you are prepared for the critical moment, there is no worry. It is precisely because communication has become an indispensable thing in life, so "preparation" is even more necessary.
To use two kinds of SIM cards, you first need a smartphone to match them. Although almost all smartphones sold recently are "Dual SIM" specifications, there is only one SIM for the OPPO Reno5A5G released by way Mobile. It will vary according to the specifications of the sales store, so be sure to confirm whether it has "double SIM" and so on before buying.
Whether your smartphone supports "Dual SIM" or not, just look at the SIM card information in "Settings". Even without using SIM, if the number is divided into "1" and "2", it can basically be used.
Even if there is only one card slot, there are "eSIM+ physical SIM" such as "iPhone (iPhone XS, iPhone XS Max, iPhone XR after iOS 12.1)," Pixel5a "," OPPO A73 ", which can use two kinds of SIM terminals. If you are not clear, go to the official website.
SIM information for OPPO A73 (from OPPO)
Smartphones have a corresponding "frequency band", so even a "Dual SIM" cannot communicate if it does not match the "frequency band" of the correspondent. The corresponding tape of the terminal must be written in the manufacturer's specification section, so don't forget the confirmation here.
Sent by the Ministry of General Affairs.
Many people don't know how to distinguish between two kinds of SIM cards. In most cases, the phone can wait with two numbers at the same time, but few terminals can set up data communication at the same time. Therefore, the switch from "primary SIM" to "secondary SIM" is done manually.
Although it may seem troublesome, as long as you remember this method, almost all manufacturers' smartphones can simply switch between SIM for data communication.
First slide from the screen and display the Control Center, and then press the Mobile Communications icon. Now, the shortcut set by the SIM card (depending on the manufacturer's display). Switching the SIM used for data communication from master to "sub-SIM" can be done.
Xiaomi's smartphone is easier because it can switch data communication SIM cards in the control center. The number of people using Dual SIM will certainly increase in the future, and it is hoped that other manufacturers will also install this feature.
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