On the sea from Jiuzhou Port in Zhuhai to Shekou Port in Shenzhen, China Unicom wcdma 3g has no signal.

It is entirely possible, even normal, that there is no Unicom wcdma 3G signal at sea. Because Unicom's wcdma frequency band is 2 100MHz, which is a very high frequency band, the signal coverage is very small, and a base station is needed from several hundred meters to more than one thousand meters. Unicom's 3G base station is completely different from its 2G base station. 3G signal coverage can only be achieved by building a brand-new base station, but not by upgrading 2G. Therefore, the poor 3G signal of China Unicom will last for a long time, and now it can only guarantee the coverage of most urban areas.

At present, the best 3G signal is China Telecom, because 3G signal is CDMA2000 standard, which is directly upgraded from CDMA 1X and inherits the advantages of low radiation and high confidentiality of CDMA. It can be said that except for extremely remote mountainous areas and rural areas, as long as there is a 3G signal, there will be a 3G signal.

The worst 3G signal is China Mobile. TD-CDMA 3G has serious congenital defects, such as large investment, small coverage and slow speed. Now China Mobile basically doesn't expect 3G, and hopes to upgrade 3G directly after three years. At present, she mainly relies on CMMB mobile TV to fool customers who don't understand 3G. She claims to have the largest number of 3G users in China, but in fact many of them are wireless landline customers.