Even in USA, there is no proper 4G coverage for many mobile networks. but there are number of 4G ready phones available in the market. the biggest advantage of the 4G is it's massive internet speed. 4G can practically achieve about 128Mbps internet speed.
Samsung again released a new 4G phone, this time it's for the ATT network. it's Samsung I997 Infuse. this phone has a 4.5 inch huge Super AMOLED Plus capacitive touchscreen and the screen resolution is 480 x 800 pixels. the outer glass is made by scratch resistant Gorilla Glass material. Samsung I997 Infuse runs Android 2.2 OS but it can upgrade to the 2.3 version. it powered by a 1.2 GHz ARM Cortex A8 processor and has a 512MB RAM.
Samsung I997 Infuse has 16GB internal memory and supports up to 32GB memory cards. other than 4G, this phone has a 21Mbps HSDPA modem and a 5.76Mbps HSUPA modem. it also has bluetooth and wi-fi. the main camera of this phone is 8MP and it supports 720p video recording. also the camera application supports Geo-tagging, touch focus, face and smile detection features. it has a 1.3MP camera at the front for video calling and you can even take pictures with it.
like all other android phones, Samsung I997 Infuse comes with many pre installed applications. it also has a good GPS receiver and a digital compass.