sonnyyu:
For people are looking for alternate for Arduino WiFi shield;-We have few threads about it:
Replacement of Arduino WiFi shield - WIFI router(openwrt compatible), Pogoplug, Raspberry Pi .
Arduino as VPN client? - #3 by sonnyyu - Networking, Protocols, and Devices - Arduino Forum
WIFI router Tp-Link WR703N for Arduino
Arduino - Wifi - iPhone - #7 by sonnyyu - Networking, Protocols, and Devices - Arduino Forum
WIFI router Tp-Link TL-WDR3600 for Arduino
Pogoplug for Arduino wifi and even housing and power supply
The bottom line is to start testing wifi with Arduino , all you need is used/junk PC plus few dollar wifi usb stick.
WIFI router Tp-Link TL-WDR3600 is dual radio 802.11n 2.4/5.0 Ghz router, use it with Arduino, you make Arduino run on 5.0 Ghz.