Why does my Android Service sleep when the phone is inactive.

Dear Reader,

During my development of an Android app for reporting periodic wifi scans, I encountered that the android service responsible for reporting the wifi-scans halted when the phone went inactive.

I searched Google and found this newsgroup thread, which gave me the answer to my problem.
Greate newsgroups answer
It also suggests how to use the AlarmManager to make a service periodically to do work.

Kind Regards Dan L. Christensen