Why does didenterregion triggers multiple times even I am already in that beacon region? - ionic2

Question

I have added one beacon region for monitoring.I am using the method didenterregion to identify when ever he enters into beacon region but the thing is even I am already in beacon region then also I am getting multiple times didenterregion signal.Can anyone help me why is this happening?
`
#Injectable()
export class BeaconProvider {
delegate: any;
region: any;
constructor(public platform: Platform, public events: Events,public IBeacon:IBeacon,public appService:AppService) {
}
initialise(): any {
let promise = new Promise((resolve, reject) => {
if (this.platform.is('cordova')) {
// Request permission to use location on iOS
this.IBeacon.requestAlwaysAuthorization();
this.IBeacon.getMonitoredRegions().then(data=>{
console.log(data);
});
this.IBeacon.getRangedRegions().then(data=>{
console.log(data);
});
this.delegate = this.IBeacon.Delegate();
// Subscribe to some of the delegate's event handlers
this.delegate.didEnterRegion()
.subscribe(
data => {
this.events.publish('this.delegate.didEnterRegion', data);
},
error => console.error()
);
this.delegate.didExitRegion()
.subscribe(
data => {
this.events.publish('this.delegate.didExitRegion', data);
},
error => console.error()
);
this.appService.getBeacons()
.subscribe(beacons => {
console.log(beacons);
var i=0;
for(i=0;i<beacons.length;i++){
// setup a beacon region – CHANGE THIS TO YOUR OWN UUID
this.region = this.IBeacon.BeaconRegion(beacons[i].beaconDetailes.beaconId,beacons[i].beaconDetailes.uuid,beacons[i].beaconDetailes.major,beacons[i].beaconDetailes.minor);
this.region.NotifyEntryStateOnDisplay = true;
this.region.NotifyOnEntry = true;
this.region.NotifyOnExit = true;
// start ranging
this.IBeacon.startMonitoringForRegion(this.region)
.then(
() => {
resolve(true);
console.log("monitor for region");
},
error => {
resolve(false);
}
);
}
}
);
} else {
resolve(false);
}
});
return promise;
}
}
`
This is the provider for beacon monitor.In some other pages I am triggering the method initialize to register beacon and start monitoring the beacons.Using events publish I am getting the beacon details when ever I entered into region in other pages.