Plug in the wireless landline's v4 card and there is no signal, but you can see what happened to the message.

Because the signal reception of SIM is cut off and the network is unstable. If you use a vivo phone, this is a method that SIM card can't recognize:

1. Insert and unplug the SIM card again, or replace another SIM card. Cutting the card may cause the SIM card to be damaged and unrecognizable.

2. Try to turn on the mobile phone flight mode and then turn it off, or change the network environment.

3. If two telecom cards are used at the same time, the secondary card (non-data card) must open the VoLTE service and open the mobile phone VoLTE HD call. At the same time, the carrier network needs to support 4G VoLTE service to use dual telecom cards, otherwise one telecom card will have no signal.

Brief introduction of wireless landline:

China Mobile pushes wireless fixed line to counterattack China Unicom fixed line market. On February 8, 2008, 65438+65438+ news, while using 3G to encroach on China mobile communication market, China Mobile also made corresponding preparations, that is, using wireless fixed line to counterattack the fixed line market of China Telecom and China Unicom. Moreover, due to its considerable attack on functions and tariffs, it is expected to create troubles for China Telecom and China Unicom.

TD wireless landline is one of the important components of TD terminal 3+ 1 scheme, namely TD mobile phone, TD network card, notebook computer with built-in TD network card and TD wireless landline. This wireless landline is actually a wireless fixed line using TD network, which is quite similar to PHS of China Telecom in business characteristics, but more advanced than PHS technology.