PhoneStateListener onCellLocationChanged does not get called in background

I've implemented a sticky-service which runs in the background. I want my app to handle gsm-Cell-changes. But my PhoneStateListener does not get called reliably. Sometimes it just gets called after i pressed a button and the phone resumes from sleep mode. How am i able to force the phone开发者_运维问答 to recognize gsm-Locationchanges reliably in a background service? Why does it sometimes work and other times not?

Put PhoneStateListener in the service and then put the requests for listening in the onStartCommand. If the service stops listening for the changes, try to create a Timer that calls for a TimerTask class inside the service which contains the listening requests and make the Timer call for the TimerTask class every X milliseconds. That worked for me.