Working pattern of background service

[beppo-ivel]

I implemented a simple app, which runs 3 services in parallel.

1. simple custom service with interval 5s
2. location service that frequently called about 30s
3. foreground notification service that starts if app is paused and starts if app resumes

The problem is, if I turn off the display, then simple service is not running frequently anymore. The location service has also no exact interval. But the point is, that the frequency of location service is independent from turning off the display. Why there is this difference between simple service and location service?

log file:

[17:24:55] background location service ... 
[17:24:56] simple custom service ...  
[17:25:01] simple custom service ...  
[17:25:06] simple custom service ...  
[17:25:11] simple custom service ...  
[17:25:16] simple custom service ...  
[17:25:21] simple custom service ...  
[17:25:25] background location service ... 
[17:25:26] simple custom service ...  
[17:25:31] simple custom service ...  
[17:25:36] simple custom service ...  
[17:25:41] simple custom service ...  
[17:25:46] simple custom service ...  
[17:25:51] simple custom service ...  
[17:25:55] background location service ... 
[17:25:56] simple custom service ...  
**[17:25:57] notification service ...** 
[17:26:01] simple custom service ...  
[17:26:06] simple custom service ...  
[17:26:12] simple custom service ...  
[17:26:17] simple custom service ...  
[17:26:22] simple custom service ...  
[17:26:28] simple custom service ...  
[17:26:29] background location service ... 
[17:26:34] simple custom service ...  
[17:26:41] simple custom service ...  
[17:26:46] simple custom service ...  
[17:26:53] simple custom service ...  
[17:26:58] background location service ... 
[17:27:01] simple custom service ...  
[17:27:08] simple custom service ...  
[17:27:17] simple custom service ...  
[17:27:24] simple custom service ...  
[17:27:28] background location service ... 
[17:27:32] simple custom service ...  
[17:27:39] simple custom service ...  
[17:27:48] simple custom service ...  
[17:27:58] simple custom service ...  
[17:27:58] background location service ... 
[17:28:07] simple custom service ...  
[17:28:14] simple custom service ...  
[17:28:19] simple custom service ...  
[17:28:25] simple custom service ...  
[17:28:28] background location service ... 
[17:28:34] simple custom service ...  
[17:28:40] simple custom service ...  
[17:28:50] simple custom service ...  
[17:28:55] simple custom service ...  
[17:28:58] background location service ... 
[17:29:05] simple custom service ...  
[17:29:11] simple custom service ...  
[17:29:20] simple custom service ...  
[17:29:25] simple custom service ...  
[17:29:30] background location service ... 
[17:29:41] simple custom service ...  
[17:29:54] simple custom service ...  
[17:30:00] background location service ... 
[17:30:07] simple custom service ...  
[17:30:22] simple custom service ...  
[17:30:30] simple custom service ...  
[17:30:36] background location service ... 
[17:30:47] simple custom service ...  
[17:31:00] simple custom service ...  
[17:31:06] background location service ... 
.
.
.
[17:35:31] background location service ... 
[17:35:44] simple custom service ...  
[17:35:55] simple custom service ...  
[17:36:05] background location service ... 
[17:36:11] simple custom service ...  
[17:36:24] simple custom service ...  
[17:36:36] background location service ... 
[17:36:37] simple custom service ...  
[17:36:54] simple custom service ...  
[17:37:07] simple custom service ...  
[17:37:07] background location service ... 
[17:37:16] simple custom service ...  
[17:37:24] simple custom service ...  
[17:37:41] simple custom service ...  
[17:37:41] background location service ...