The iPhone 4s doesn't support 4G WIFI. Although the iPhone 4s is equipped with an antenna and supports Wi-Fi and Bluetooth, it only supports 2.4 GHz and 5 GHz Wi-Fi bands, not 4G WIFI bands. It wasn't until the iPhone 5 that 4G WIFI was available for the first time.
The correct answer is: No, previously only 2G, 3G.