@INTP
Thanks for your reply.
I practiced with some examples. I am using ardiono UNO, ethernet shield, DHT11 sensor, and a Relay switch. I made a web page using jsp, jquery mobile to show sensor value every 2 seconds, and it has on/off buttons to control relay.
But I didn't make database table yet, also the button on/off is not sended to arduino side.
I am going to use wifi, as I showed in the attached photo. Distance will be just a wifi range. Just a farmer can see and control his inside livestock house with his phone, in his shelter.