This article talks about public network intercoms.

1: The communication distance is extremely long. In theory, as long as the signal of China Mobile, China Unicom and China Telecom is covered, intercom can be carried out. This is the biggest difference between it and radio intercom. Radio signals are greatly affected by the environment. There will be many signal blind spots in a building (such as basements, rooms within rooms, etc.), but public network intercoms can be used as long as there is a mobile phone signal, from Mohe in the north to Sansha in the south.
2: As mentioned earlier, public network intercoms can be regarded as simplified smartphones, which means that they can develop functions that radio intercoms do not have. For example, groups can be set up freely, and the screen can show who is currently calling. There can be a GPS function, which can see the location of any machine in the group. Intercom records can be played back, and other functions can be used to talk to other machines in the group separately.
3: Public network intercoms can be made very small, and if you don't want a screen, they can even be made the size of a button.
4: As a small-screen mobile phone with simplified functions, public network intercoms can save power compared to radio intercoms, and there will be no power anxiety with a standby time of more than three days.
Five: Strong anti-interference, no common background noise of radio walkie-talkies, clear intercom voice, just like making a phone call or WeChat voice.
Six: Whether the public network intercom can communicate normally depends not only on the mobile phone signal, but also on the stability of the intercom platform. If the platform server of a small brand is unstable or simply runs away, the intercom will become a decoration.

Use scenarios of public network intercom. In addition to general intercom applications (construction sites, security, self-driving, cycling, etc.), public network intercoms can also be used in some special scenarios: 1: For the elderly and children, just one-click calling function is enough. Especially for the elderly, who are dizzy and trembling and cannot or will not use mobile phones, just press and hold the button to call, and family members can also use the APP to locate the elderly or children. 2: Under the same brand or platform, a nationwide voice chat group can be formed. 3: Commercial freight fleets can chat with colleagues from all over the world without affecting normal driving.
The disadvantage is that public network intercoms can only be used in places with mobile phone signal coverage.