Want internet access on my desktop using my airtel 4G without having to physically connect my smartphone using tethering. As my desktop is old I don't want to spend much. Will this be enough: Terabyte Usb 2.0 Wireless Wifi 802.11N USB Adapter - Terabyte : Flipkart.com! Can I expect decent speed using above adapter? I get 10 to 20 mbps with tethering by using cable.