Android wifi power question

I have observed that by default the wifi adaptor goes into (power saving mode) PSM mode. When Certain applications such as youtube appear to buffer video, the adaptor leaves PSM mode into CAM state or full power mode. Once the buffering is done, the wifi adaptor goes back into PSM mode. I have observed this behavior with other applications as well. Is there 开发者_JAVA技巧an API call that supports this kind of behavior? It's not clear from the documentation how to switch the WIFI adapator in and out of PSM mode.

WiFi goes PSM or CAM not under Application's control, it's the 802.11 Power Management Mode -- whenever there is traffic, the WiFi goes to CAM, when transfer is done, it goes back to PSM. On application layer, you simply generate some traffic, the NIC driver will automatically transit to right mode.