In this chapter, you have learned about some wireless terminology and available hardware, and sent some bytes over the air. Your XBee network is even secured against eavesdropping. You have already used an Arduino as a simple forwarder of data, but it is time to put your Arduinos in control of the XBee modules and get them talking to each other! The next chapter will show how to connect your XBee modules to your Arduino and how to exchange some simple sensor data.