The SIM Card suddenly not working (no service)

I has an iPhone 7 Plus. I used my SIM card for 1 year more (almost 2 year) in this phone. I never drop my phone or got a water and something else. Also i using this phone for normal activity, like gaming, browsing and listen some music. I dont know why, my sim card is suddenly stop working (no service). How could its possibly happen? Please give me solution for this problem