LTE-Advanced has been making steady progress across the globe with many operators. A key features are its carrier aggregation techniques that bond two or more separate radio channels for more speed and capacity. Multiple input, multiple output (MIMO) antenna arrays of 2×2 or more on the devices and infrastructure for faster uplink and downlinks. Support for “hetnets,” which give operators ways to combine multiple access methods, including WiFi and 3G, at the RAN and the core network. Relay nodes, low-power radios that will provide improved coverage and capacity at the cell edge of the network.