The Atmel AT86RF212B single-chip radio transceiver provides a complete radio transceiver interface between an antenna and a microcontroller. It comprises the analog radio，digital modulation and demodulation including time and frequency synchronization，as well as data buffering. A single 128-byte TRX buffer stores receive or transmit data. Communication between transmitter and receiver is based on direct sequence spread spectrum with different modulation schemes and spreading codes.