This chart here summarizes the two methods that are being standardized in the industry among the various alliance groups. For WPC Qi, the induction method currently define Baseline Power Profile (BPP) up to 5 W and Extended Power Profile (EPP) up to 15 W. The switching frequency for these two are from 110 kHz-205 kHz. The, WPC group is in the process of defining medium power specs up to 60 W/120 W. In 2016, the PMA and Rezence groups combined to formed AirFuel Alliance. The PMA induction method is specified up to 5 W for <480 kHz, while the Resonance method is specified up to 6 W at 6.78 MHz. NFC is another Magnetic Resonance standardization group that currently specs power up to 3 W at 13.56 MHz.