I'm sharing the answer for my own question as this might help others
Steps:
1: Add "Required background modes" key in your application-info.plist and assign value as "App provides Voice over IP services" to its item.
2: In your appdelegate.m file, implement the "applicationDidEnterBackground:" method as below code snippet.
static int counter;
- (void)applicationDidEnterBackground:(UIApplication *)application
{
//Minimun keepAliveTimeout is 600 seconds
[[UIApplication sharedApplication] setKeepAliveTimeout:605 handler:^{
//do your task
counter ++;
NSLog(@"Counter # %d", counter);
}];
}
Here for example, i'm printing the counter variable in the given time interval
Below is the Output Log message:
2012-08-27 14:06:09.216 BackgroundApplicationForVOIP[1129:207] Counter # 1
2012-08-27 14:16:14.218 BackgroundApplicationForVOIP[1129:207] Counter # 2
2012-08-27 14:26:19.219 BackgroundApplicationForVOIP[1129:207] Counter # 3
2012-08-27 14:36:24.220 BackgroundApplicationForVOIP[1129:207] Counter # 4
2012-08-27 14:46:29.221 BackgroundApplicationForVOIP[1129:207] Counter # 5
2012-08-27 14:54:21.000 BackgroundApplicationForVOIP[1129:207] Counter # 6
2012-08-27 15:19:48.099 BackgroundApplicationForVOIP[1129:207] Counter # 7
2012-08-27 15:26:03.201 BackgroundApplicationForVOIP[1129:207] Counter # 8
2012-08-27 15:39:50.167 BackgroundApplicationForVOIP[1129:207] Counter # 9
2012-08-27 16:07:28.112 BackgroundApplicationForVOIP[1129:207] Counter # 10
2012-08-27 16:13:43.217 BackgroundApplicationForVOIP[1129:207] Counter # 11
2012-08-27 16:23:48.218 BackgroundApplicationForVOIP[1129:207] Counter # 12
2012-08-27 16:33:53.219 BackgroundApplicationForVOIP[1129:207] Counter # 13
2012-08-27 16:43:58.220 BackgroundApplicationForVOIP[1129:207] Counter # 14
2012-08-27 16:54:03.221 BackgroundApplicationForVOIP[1129:207] Counter # 15