Sending BLE device data to server in background

I develop an application that reading data from BLE device and send this data to MQTT broker (server). But when application entering to the background, data sending stopped after 3 minutes (I use Background Tasks). How I can increase this time. Or maybe there is an official mechanism, that Apple promotes and will not reject on the confirmation step on App Store, for reading data from BLE and sending this data to the server in the background that not limited by time?
My Background Task:

AYBackgroundTask.h

@interface AYBackgroundTask : NSObject

@property (assign) UIBackgroundTaskIdentifier identifier;
@property (strong, nonatomic) UIApplication *application;

+ (void)run:(void(^)(void))handler;

- (void)begin;
- (void)end;

@end

AYBackgroundTask.m

@implementation AYBackgroundTask

+ (void)run:(void(^)(void))handler {
  AYBackgroundTask *task = [[AYBackgroundTask alloc] init];
  [task begin];
  handler();
}

- (void)begin {
  self.identifier = [self.applicationn beginBackgroundTaskWithExpirationHandler:^{
    [self end];
  }];
}

- (void)end {
  if (self.identifier != UIBackgroundTaskInvalid) {
    [self.application.application endBackgroundTask:self.identifier];
  }
  self.identifier = UIBackgroundTaskInvalid;
}

@end

There is here who faced with this problem?
Best regards,
Anton.