Why walkie-talkies don't need base stations and calling cards?

Generally when we see the walkie-talkie usually find that they are mainly used for some rescue activities, or for some special groups, as if only with the help of a small machine can be completed, neither like a cell phone as every month to recharge the phone bill, but also do not need to signal the help of the base station, so why walkie-talkie can not rely on the base station can also be used?

We have to be clear, that is to say, these walkie-talkies, its data signal frequency and cell phone data signal frequency is very different. When the network signal of the cell phone becomes more and more advanced, its frequency appears to become higher and higher, and the frequency of the 4G base station has long exceeded more than 2,000 megahertz.

In comparison, the average walkie-talkie only has frequencies ranging from 100 to 400 megahertz. We know that the lower the frequency, the wider the propagation area, so walkie-talkies are inherently more distant than cell phone signals, so within this area, there is no need to create a signal base station to assist in the transmission.