My mobile phone is r8 17 dual card dual standby. How to set up a card to surf the internet and a card to answer the phone and send text messages?

In general, default cards can be set for mobile phone data service and voice service respectively. You can set the card you want to surf the Internet in the data access settings. Even if there is no signal, the mobile phone will not use the second card to surf the Internet, but the settings of various mobile phones are different. Some mobile phones can choose the prompt method, which can use the first card to make a phone call and send a text message by default, or prompt every time you make a phone call and send a text message. Or you can see two icons every time you make a phone call or send a text message, card 1 and card 2. Use whichever you order, because I haven't used r8 17 and I don't have time to read it carefully. I can only remind you.