Cycling along the Nujiang River from Liuku Town in Lushui, Yunnan Province to Bingzhongluo Village, which carrier’s network reception is better along the way?

I am currently using China Unicom. If I arrive at Nujiang, I am afraid that the network will be poor and I will not be able to receive it. How is the use of China Unicom in Nujiang? If not, what carrier is better?