I tried calling you on your mobile.
　　我试着打过你的手机。

　　A：I tried calling you on your mobile.
　　A：我试着打过你的手机。

　　B：What time was that?
　　B：什么时候?

　　A：It was about an hour ago. But I couldn’t get you.
　　A：大约1小时以前。但是不能和你联系上。

　　B：I was on the subway. I don’t think you can get a signal underground.
　　B：我在地铁上。我想地铁里没有信号。

　　There are various situations and reasons for not receiving a phone call.
　　有很多情形和原因不能接到电话。