iPhone useless when phone in lock screen mode even if wifi on
I have lost my iPhone at home, and I have setup find my iphone on it (and used it before successfully).
The wireless on my iPhone is on, and it's at home, so it can connect to the wifi if it wants to.
BUT, seems that iPhone automatically turns off wifi (presumably to save power?) when it goes into lock screen mode, and never pings the wifi again.
How am I supposed to find it?? Very frustrating...
iPhone 5s, iOS 7.1.1