bluetooth-central UIBackgroundModes is enabled.
As application goes to background calling
[centralManager scanForPeripheralsWithServices:[NSArray arrayWithObjects:[[NSUUID alloc] initWithUUIDString:SERVICE_UUID], nil] options:nil];
but no callback recieved for (waited for longer than 10 min also)
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI;
once un-lock the phone immediately get the didDiscoverPeripheral callback and the BLE device discovered.