NFC operates in the unlicensed 13.56 MHz band and can be used as an out-of-band communication link for in-vehicle and Bluetooth. Setting up a link via Wi-Fi or Bluetooth is a complicated process that the average consumer is unable to accomplish, but by implementing NFC, consumers can simply touch their phone to the NFC receiver in a car and secure a wireless connection, rather than having to search for networks or set up a W2A pass phrase. One in-vehicle primary advantage of using NFC to provision a Bluetooth or Wi-Fi connection is that NFC is easier to set up than more complex radios, and the setup time is generally shorter (on the order of milliseconds). NFC leverages the principle of magnetic induction to establish a communication link between two devices employing loop antennas. The effective range of link is no more than a few centimeters, so in-vehicle the user experience for setting up the connection is built around close proximity or touch.
refer to: http://embedded-computing.com/articles/wireless-accelerate-next-wave-in-vehicle-innovation/
