I am working in an Angular 4 application ,In this I need to call a API in every 15 minutes interval.I read some stackoverflow post but I couldn't get what I exactly looking for .

This is what I have tried so far.

```
 UPDATE_USER_SESSION() {

        this.publicIp.v4().then(ip => {
            this.END_USER_SESSION(ip)
        })

        this.publicIp.v4().then(ip => {
            this.INSERT_USER_SESSION(ip)
        })
    }

```

I have this method out side of my ngOnInit .and I want call this method every 15 minutes interval.

Inside ngOnInit I have the following 

```
import 'rxjs/add/observable/interval';

    this.call = Observable.interval(10000)
                .subscribe((val) => { this.UPDATE_USER_SESSION() });

```

Can any one guide me to solve this .