Remote Desktop Problem

[matchstickredgti]

When I'm connected to my wifi at home, I can connect to my PC with my phone, but if I switch to my data connection, it says it can't connect. I've tried my 192.168.x.x IP that the router assigns and I've also tried my public IP.

I also can't connect (to my home PC) if I'm at my friends house, connected to his wifi.

For the 'computer' field, that's where I put my IP. Then my username and password. Domain name is blank, should I be putting anything there. I don't even know my domain name, if I have one.

Should I be trying to connect to the router's IP if I'm connecting from outside my own wifi network?

I have a Belkin router if that helps

thanks