4G is the the fourth generation wireless technology adopted by the ITU and carriers around the world. As with previous standards, 4G implements among carriers vary ranging from LTE to WiMax. So just how does 4G work?
4G has a number of capabilities including high-speed data transfers that are many times faster as compared to top 3G data transfer speed, smooth handovers between cell towers and disparate networks, uses IP-packets throughout the network.
LTE is a leading implementation of 4G. LTE Advanced is an enhancement to LTE making it easier for carriers to adopt; however, the approach does not allow existing LTE phones to work on an LTE advanced network. LTE advanced allows carriers to have more concurrent users on their existing spectrum, making unlimited data plans possible for consumers. Another implementation of 4G is WiMax.
WiMax is known as metro WiFi and is capable of delivering wireless internet to homes and business in rural areas. WiMax is a 4G technology and can deliver transfer speeds on par with LTE Advanced networks.
The underlying physical layer uses MiMO – multiple input, multiple output, antennas on phones and cells to improve communication performance and allow simultaneous voice and data. The physical layer also supports variable bit rates based on channel conditions on a per-user basis. 4G also offers advanced error checking and correction on the physical layer. The access scheme is OFDMA, to make better use of available spectrum. OFDMA is like CDMA yet is MIMO friendly and can avoid problems with multipath interference.