Hii friends I was using a TATA DOCOMO sim untill the last month it was very bad network, so I ported to airtel which shows advertisements as their network is very good but after I ported I am getting irritated by their internet, when I stand outside my house I get 3G signal but when I come inside my house its 2G but their quality of calls is at the top than any other network in india and network coverage is also good that is why I am still keeping this sim. Once they were the best in their field now their quality has fallen