I am currently using a Nokia smartphone and it is giving me a headache. I don’t know where to go. Can an expert give me some advice?

I usually choose GPRS Internet. In fact, they are all the same, the key is to activate the monthly Internet subscription. Displaying open applications refers to things running in the background. Because it is intelligent, many functions can be performed at the same time. You can check which functions are enabled at any time so that you can close programs that are not in use temporarily. Regarding traffic, your situation is normal. Smartphones consume more traffic than ordinary machines, which is also a prerequisite for fast Internet access. My 5320di monthly 150M traffic is barely enough.