How does the contact time get into my iPod nano?
The sensor sends this information wirelessly to the receiver that is plugged into the iPod nano. The sensor communicates with the receiver via a proprietary low-power 2.4 GHz radio protocol; this is not Bluetooth or Wi-Fi. The Nike + iPod sensor has been engineered and tested to ensure that it does not interfere with Bluetooth, Wi-Fi, cellular, cordless phones, or similar electronic devices.