Introduction:
Wireless power is beginning to show great potential in the consumer market. The ability to power an electronic device without the use of wires not only provides a convenient solution for the users of portable devices, but also gives designers the ability to develop more creative answers to problems. This technology’s benefits can immediately be seen in any portable device that normally operates on battery power from cell phones to electric cars. Inductive coupling is the method that achieves efficient and versatile wireless power. For the ease of use and benefit to both designers and consumers, a standard has been developed. The Wireless Power Consortium (WPC) standard creates interoperability between the device providing power (power transmitter, charging station), and the device receiving power (power receiver, portable device). This standard defines the inductive coupling requirements (coil configuration), and the communication protocol. Any device operating under the WPC standard is compatible with any other WPC compliant device. One key benefit to this approach is the communication protocol, which makes use of the coils for communications between the power transmitter and the power receiver.
Also see "Introduction to the Wireless Power Consortium Standard"
http://focus.ti.com/general/docs/lit/getliterature.tsp?baseLiteratureNumber=slyt401
