how to implement 2 way communication b/w android app and GPRS modem

Question

I am new in java and android programming and also eclipse environment. I have to make a run time connection b/w android app and GPRS modem placed in my home. I have to send numbers from GPRS modem to my app and vise verse. I read many questions on stackoverflow. I know i have to make a tcp/ip connection and a server b/w my app and GPRS modem. But I don't know where to implement server. Can anyone tell me step by step process?

** I want that my app use any available internet connection(wifi, gprs etc) on phone for communication, not specifically gprs connection.

Answer 1

I can suggest my way but there may be more ways to do it.

1) Android App should communicate with a web server in PHP ,ruby etc.

2)The web server communicates to GPRS modem with a public IP addrees

3)The state of GPRS modem is controlled by the web server.