Running NSTimer background for more than 10 min

Question

Iam working on Alarm application, I need to repeat a timer in background for every one minute to checke the fire date of Alarm,and when the alarm fired i need to play audio for 15 min

So for running timer in background i have written the bellow code,but it doesnot work, it is working upto 10 min background after that my app is terminating, please help me what i did wrong and how i should implement.

My code is:

- (void)applicationDidEnterBackground:(UIApplication *)application
{
    //Making background task Asynchronous
    if([[UIDevice currentDevice]   respondsToSelector:@selector(isMultitaskingSupported)])
    {
        __block UIBackgroundTaskIdentifier  taskId = 0;     taskId =
        [application beginBackgroundTaskWithExpirationHandler:^
         {
             taskId = UIBackgroundTaskInvalid;
         }];

        if(self.callTimer)
        {
               if([self.callTimer isValid])
               [self.callTimer invalidate];
              self.callTimer = nil;
        } 
         self.callTimer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(recall_timer) userInfo:nil repeats:YES];
         [[NSRunLoop currentRunLoop] addTimer:self.callTimer forMode:NSRunLoopCommonModes];
     }
  }