Unicom has covered 3G networks in most parts of the country, but it does not rule out that rural or urban 3G networks in some areas are not fully covered. Sometimes the 3G network coverage is incomplete or the 3G signal has blind spots in some places, which will cause your mobile phone to search the 3G network signal online, or the 3G signal searched is very weak. At this time, you can switch to the 2G signal. If there is no 2G signal, it may be that the construction of your local Unicom base station is not strong enough, and the coverage of the base station is small, resulting in the mobile phone not receiving Unicom signal. People can solve this problem by optimizing wireless networks and increasing the density of base stations and distribution systems. Because the project construction needs a process, China Unicom is also adding base stations and distribution systems to improve network signal coverage.