title: Android, wifi active scans
body: <p>I need a frequent wifi scan on my android application (I'm trying to build a local indoor positioning system based on wifi RSSI values). IF I call wifi.startScan() I have onReceive() called back once every 6 seconds (I suppose by default it's scanning passively): how do I get more frequent callbacks? Should I ask for "active" scans? How is it done? Are there any drawbacks?</p>