Why is there no network to send messages to each other? The network can't be opened.

Send a message to the other party when there is a network, and the other party will definitely not receive it when there is no network.

At this time, you can check whether your mobile phone traffic is turned on. If the wireless LAN is connected, you can check whether the wireless transmitter is damaged.

A network is a graph composed of several nodes and links connecting these nodes, representing many objects and their relationships. The network has the characteristics of resource sharing, rapid information transmission, improved system reliability, easy distributed processing and comprehensive information service.