[Nexus 7 3G Android Development] lordfreyr:
I downloaded an app which tries to ping the router every 15 minutes and reconnects if can't reach it, but it didn't work. According to it I had no WLAN connection from 02:35 til 08:00 when my alarm went off and I disabled/re-enabled the WLAN myself.

Now, what does this mean:

D/WifiService( 579): Client connection lost with reason: 4

Logcat with grep Wifi:

05-28 23:09:19.218 D/WifiService( 579): New client listening to asynchronous messages
05-28 23:09:19.219 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@2028a108}
05-28 23:09:19.403 E/WifiService( 579): Multicaster binderDied
05-28 23:09:19.405 D/WifiService( 579): Client connection lost with reason: 4
05-28 23:09:19.559 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@2028a108}
05-28 23:09:19.574 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@43d174c}
05-28 23:09:19.897 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@43d174c}
05-28 23:09:25.301 D/WifiService( 579): New client listening to asynchronous messages
05-28 23:09:30.935 D/WifiService( 579): Client connection lost with reason: 4
05-28 23:23:43.693 D/WifiService( 579): New client listening to asynchronous messages
05-28 23:23:43.694 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@7d035eb}
05-28 23:23:43.736 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@7d035eb}
05-28 23:23:43.739 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@22d6bf48}
05-28 23:23:43.801 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@22d6bf48}
05-28 23:38:43.852 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@1fb59a08}
05-28 23:38:43.883 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@1fb59a08}
05-28 23:38:43.884 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@3f7135a1}
05-28 23:38:43.905 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@3f7135a1}
05-28 23:53:22.463 E/WifiService( 579): Multicaster binderDied
05-28 23:53:22.463 D/WifiService( 579): Client connection lost with reason: 4
05-28 23:54:43.002 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@36a3faa8}
05-28 23:54:43.043 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@36a3faa8}
05-28 23:54:43.044 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@1036f566}
05-28 23:54:43.078 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@1036f566}
05-29 00:00:00.697 D/WifiService( 579): Client connection lost with reason: 4
05-29 00:05:29.533 D/WifiService( 579): Client connection lost with reason: 4
05-29 00:09:28.943 D/WifiService( 579): New client listening to asynchronous messages
05-29 00:09:28.943 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@1ce3dc99}
05-29 00:09:29.036 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@1ce3dc99}
05-29 00:09:29.037 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@358ca955}
05-29 00:09:29.072 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@358ca955}
05-29 00:16:16.695 I/ActivityManager( 579): Start proc 13747:org.fdroid.fdroid/u0a164 for broadcast org.fdroid.fdroid/.receiver.WifiStateChangeReceiver
05-29 00:16:17.196 D/WifiService( 579): New client listening to asynchronous messages
05-29 00:16:32.205 I/ActivityManager( 579): Waited long enough for: ServiceRecord{f9a4bd3 u0 org.fdroid.fdroid/.net.WifiStateChangeService}
05-29 00:23:43.523 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@b75003c}
05-29 00:23:43.554 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@b75003c}
05-29 00:23:43.555 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@314b91c5}
05-29 00:23:43.584 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@314b91c5}
05-29 00:40:20.854 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@1de7347d}
05-29 00:40:20.885 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@1de7347d}
05-29 00:40:20.885 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@31d9f72}
05-29 00:40:20.956 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@31d9f72}
05-29 00:53:43.495 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@1cba1eff}
05-29 00:53:43.662 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@1cba1eff}
05-29 00:53:43.662 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@28eb14cc}
05-29 00:53:43.690 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@28eb14cc}
05-29 01:12:01.373 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@33e98393}
05-29 01:12:04.192 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@33e98393}
05-29 01:12:04.193 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@1735ffd0}
05-29 01:12:04.232 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@1735ffd0}
05-29 01:25:01.280 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@3169bb94}
05-29 01:25:01.337 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@3169bb94}
05-29 01:25:01.341 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@29a4263d}
05-29 01:25:01.369 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@29a4263d}
05-29 01:38:43.665 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@884773}
05-29 01:38:43.977 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@884773}
05-29 01:38:43.978 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@35bda630}
05-29 01:38:44.001 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@35bda630}
05-29 01:54:02.291 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@89687fa}
05-29 01:54:02.339 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@89687fa}
05-29 01:54:02.344 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@2ae241ab}
05-29 01:54:02.368 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@2ae241ab}
05-29 02:00:24.853 D/WifiService( 579): New client listening to asynchronous messages
05-29 02:08:43.730 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@24937f0a}
05-29 02:08:43.784 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@24937f0a}
05-29 02:08:43.785 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@f3e537b}
05-29 02:08:43.811 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@f3e537b}
05-29 02:23:43.602 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@d3686dc}
05-29 02:23:43.642 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@d3686dc}
05-29 02:23:43.645 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@2776a3e5}
05-29 02:23:43.698 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@2776a3e5}
05-29 02:35:35.168 D/WifiService( 579): Client connection lost with reason: 4
05-29 02:38:43.786 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@22267285}
05-29 02:38:43.817 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@22267285}
05-29 02:38:43.818 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@192178da}
05-29 02:38:43.840 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkNetworkAccess type=1 binder=android.os.BinderProxy@192178da}
05-29 02:41:59.766 D/WifiService( 579): New client listening to asynchronous messages
05-29 02:42:15.560 I/ActivityManager( 579): Waited long enough for: ServiceRecord{19a56d3d u0 org.fdroid.fdroid/.net.WifiStateChangeService}
05-29 02:42:27.606 D/WifiService( 579): Client connection lost with reason: 4
05-29 02:42:31.094 D/WifiService( 579): Client connection lost with reason: 4
05-29 03:42:51.009 D/WifiService( 579): New client listening to asynchronous messages
05-29 03:42:51.169 D/WifiService( 579): acquireWifiLockLocked: WifiLock{MyWifiLock type=3 binder=android.os.BinderProxy@3e087fcb}
05-29 03:43:08.479 D/WifiService( 579): releaseWifiLockLocked: WifiLock{MyWifiLock type=3 binder=android.os.BinderProxy@3e087fcb}
05-29 05:29:16.805 D/WifiService( 579): Client connection lost with reason: 4
05-29 05:29:28.131 D/WifiService( 579): New client listening to asynchronous messages
05-29 05:29:28.132 D/WifiService( 579): acquireWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@d51494a}
05-29 05:29:28.160 D/WifiService( 579): releaseWifiLockLocked: WifiLock{checkWifiStatus type=1 binder=android.os.BinderProxy@d51494a}
05-29 05:30:28.386 D/WifiService( 579): setWifiEnabled: false pid=6473, uid=10015
05-29 05:30:28.386 E/WifiService( 579): Invoking mWifiStateMachine.setWifiEnabled
05-29 05:30:28.775 D/WifiService( 579): setWifiEnabled: false pid=6473, uid=10015
05-29 05:30:28.776 E/WifiService( 579): Invoking mWifiStateMachine.setWifiEnabled
05-29 05:30:31.684 D/WifiService( 579): New client listening to asynchronous messages
05-29 05:30:45.878 D/WifiService( 579): setWifiEnabled: true pid=6473, uid=10015
05-29 05:30:45.878 E/WifiService( 579): Invoking mWifiStateMachine.setWifiEnabled
05-29 05:30:49.849 D/WifiService( 579): New client listening to asynchronous messages
05-29 05:30:55.604 D/WifiService( 579): Client connection lost with reason: 4
05-29 05:30:55.730 D/WifiService( 579): Client connection lost with reason: 4
05-29 05:30:56.590 E/WifiService( 579): Multicaster binderDied
05-29 05:30:56.590 D/WifiService( 579): Client connection lost with reason: 4
05-29 05:31:31.477 D/WifiService( 579): Client connection lost with reason: 4
05-29 05:33:01.552 D/WifiService( 579): New client listening to asynchronous messages
05-29 05:33:09.073 D/WifiService( 579): Client connection lost with reason: 4
05-29 05:33:09.074 E/WifiService( 579): Multicaster binderDied
05-29 06:25:20.218 D/WifiService( 579): Client connection lost with reason: 4
05-29 06:26:09.906 D/WifiService( 579): New client listening to asynchronous messages
05-29 06:26:14.675 D/WifiService( 579): New client listening to asynchronous messages
05-29 06:26:24.909 I/ActivityManager( 579): Waited long enough for: ServiceRecord{132a4aea u0 org.fdroid.fdroid/.net.WifiStateChangeService}
05-29 06:26:40.560 D/WifiService( 579): New client listening to asynchronous messages
05-29 06:26:40.569 D/WifiService( 579): acquireWifiLockLocked: WifiLock{MyManualSyncWifiLock type=3 binder=android.os.BinderProxy@2bb5a778}
05-29 06:26:40.969 D/WifiService( 579): releaseWifiLockLocked: WifiLock{MyManualSyncWifiLock type=3 binder=android.os.BinderProxy@2bb5a778}
05-29 06:26:53.822 D/WifiService( 579): Client connection lost with reason: 4
05-29 06:27:09.140 D/WifiService( 579): acquireWifiLockLocked: WifiLock{BaseSyncManager type=1 binder=android.os.BinderProxy@2589076d}
05-29 06:27:13.587 D/WifiService( 579): releaseWifiLockLocked: WifiLock{BaseSyncManager type=1 binder=android.os.BinderProxy@2589076d}
05-29 06:28:26.785 I/ActivityManager( 579): Start proc 1937:org.fdroid.fdroid/u0a164 for broadcast org.fdroid.fdroid/.receiver.WifiStateChangeReceiver
05-29 06:28:27.265 D/WifiService( 579): New client listening to asynchronous messages
05-29 06:28:42.273 I/ActivityManager( 579): Waited long enough for: ServiceRecord{c5430f8 u0 org.fdroid.fdroid/.net.WifiStateChangeService}
05-29 06:30:57.763 E/WifiService( 579): Multicaster binderDied
05-29 06:30:57.763 D/WifiService( 579): Client connection lost with reason: 4
05-29 07:31:14.591 D/WifiService( 579): New client listening to asynchronous messages
05-29 07:31:14.607 D/WifiService( 579): acquireWifiLockLocked: WifiLock{MetadataSyncService type=1 binder=android.os.BinderProxy@1ce64f67}
05-29 07:31:20.182 D/WifiService( 579): releaseWifiLockLocked: WifiLock{MetadataSyncService type=1 binder=android.os.BinderProxy@1ce64f67}
05-29 08:00:56.321 D/WifiService( 579): New client listening to asynchronous messages
05-29 08:01:02.255 D/WifiService( 579): Client connection lost with reason: 4
05-29 08:23:40.157 I/ActivityManager( 579): Start proc 13518:org.fdroid.fdroid/u0a164 for broadcast org.fdroid.fdroid/.receiver.WifiStateChangeReceiver
05-29 08:23:40.602 D/WifiService( 579): New client listening to asynchronous messages
05-29 08:28:34.700 I/ActivityManager( 579): Waited long enough for: ServiceRecord{3dd89050 u0 org.fdroid.fdroid/.net.WifiStateChangeService}
05-29 09:10:15.697 D/WifiService( 579): Client connection lost with reason: 4
05-29 09:10:15.923 E/WifiService( 579): Multicaster binderDied
05-29 09:10:15.923 D/WifiService( 579): Client connection lost with reason: 4
05-29 09:10:16.592 D/WifiService( 579): Client connection lost with reason: 4
05-29 09:10:18.607 D/WifiService( 579): Client connection lost with reason: 4
05-29 09:21:17.169 I/ActivityManager( 579): Start proc 16061:org.fdroid.fdroid/u0a164 for broadcast org.fdroid.fdroid/.receiver.WifiStateChangeReceiver
05-29 09:21:18.799 D/WifiService( 579): New client listening to asynchronous messages
05-29 09:21:33.813 I/ActivityManager( 579): Waited long enough for: ServiceRecord{365c62eb u0 org.fdroid.fdroid/.net.WifiStateChangeService}
05-29 09:31:14.451 D/WifiService( 579): Client connection lost with reason: 4
05-29 09:47:43.745 D/WifiService( 579): New client listening to asynchronous messages
05-29 09:49:22.422 D/WifiService( 579): New client listening to asynchronous messages
05-29 09:49:26.656 D/WifiService( 579): Client connection lost with reason: 4
05-29 09:51:56.086 D/WifiService( 579): Client connection lost with reason: 4
05-29 09:52:49.659 E/WifiStateMachine( 579): cancelDelayedScan -> 520
05-29 09:53:20.697 E/WifiStateMachine( 579): WifiStateMachine L2Connected CMD_START_SCAN source -2 519, 520 -> obsolete
05-29 10:04:49.415 E/WifiStateMachine( 579): cancelDelayedScan -> 521
05-29 10:04:54.899 D/WifiService( 579): New client listening to asynchronous messages
05-29 10:04:58.758 D/WifiService( 579): New client listening to asynchronous messages
05-29 10:05:09.908 I/ActivityManager( 579): Waited long enough for: ServiceRecord{1bed1de0 u0 org.fdroid.fdroid/.net.WifiStateChangeService}
05-29 10:05:26.112 D/WifiService( 579): Client connection lost with reason: 4
05-29 10:08:26.135 D/WifiService( 579): Client connection lost with reason: 4
05-29 10:09:23.788 D/WifiService( 579): New client listening to asynchronous messages
05-29 10:09:31.643 D/WifiService( 579): acquireWifiLockLocked: WifiLock{ES Wifi Lock type=3 binder=android.os.BinderProxy@10a35809}
05-29 10:09:31.657 D/WifiService( 579): releaseWifiLockLocked: WifiLock{ES Wifi Lock type=3 binder=android.os.BinderProxy@10a35809}
05-29 10:09:32.630 D/WifiService( 579): acquireWifiLockLocked: WifiLock{ES Wifi Lock type=3 binder=android.os.BinderProxy@1602191a}
05-29 10:09:32.795 D/WifiService( 579): releaseWifiLockLocked: WifiLock{ES Wifi Lock type=3 binder=android.os.BinderProxy@1602191a}