Silicon Labs, a US-based silicon, software and IoT developer, has demoed here their Flex Gecko 32-bit wireless multi-protocol SoC that runs on ARM's mbed platform. It has support for 2.4GHz frequency band and 6LoWPAN, allowing for transmission over IEEE 802.15.4. It can also support Bluetooth Low Energy specification. The MCU can use ARM Cortex-M3 or M4 for processing. If you have a license for white band or sub Ghz band then it can also be configured to send and receive the data at 600Mhz and 700Mhz. It can work with a power as high as 20 dBm.